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1
Papanikolaou, N., and I. Wierzba. "Effect of Burner Geometry on the Blowout Limits of Jet Diffusion Flames in a Co-Flowing Oxidizing Stream." Journal of Energy Resources Technology 118, no. 2 (June 1, 1996): 134–39. http://dx.doi.org/10.1115/1.2792704.
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The effects of changes in the jet nozzle geometry, i.e., nozzle shape and lip thickness, on the blowout limits of jet diffusion flames in a co-flowing air stream were experimentally investigated for a range of co-flow air stream velocities. Circular and elongated nozzles of different axes rations were employed. Preliminary results showed that nozzles with low major-to-minor axes ratios improved, while high ratios reduced, the blowout limit of attached flames compared with that for an equivalent circular nozzle. The nozzle shape had no apparent influence on the blowout limits lifted flames and the limiting stream velocity. The experimental blowout limits of lifted flames were found to be a function of the co-flowing stream velocity and jet discharge area. On the other hand, the stability of attached flames was a function of the co-flowing stream velocity, jet discharge area as well as the nozzle shape. The effect of premixing a fuel with the surrounding air was also studied. Generally, the introduction of auxiliary fuel into the surrounding stream either increased or decreased the blowout limit depending on the type of flame stabilization mechanism prior to blowout. The stability mechanism of the flame was found to be a function of the co-flow stream velocity and the auxiliary fuel employed.
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Papanikolaou, N., and I. Wierzba. "The Effects of Burner Geometry and Fuel Composition on the Stability of a Jet Diffusion Flame." Journal of Energy Resources Technology 119, no. 4 (December 1, 1997): 265–70. http://dx.doi.org/10.1115/1.2795000.
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The effect of the burner configuration and fuel composition on the stability limits of jet diffusion flames issuing into a co-flowing air stream is presented. Circular and elliptic nozzles of various lip thicknesses and aspect ratios were employed with methane as the primary fuel and hydrogen, carbon dioxide, and nitrogen as additives. It was found that the effects of nozzle geometry, fuel composition, and co-flowing stream velocity on the blowout limits were highly dependent on the type of flame stabilization mechanism, i.e., whether lifted or rim-attached, just prior to blowout. The blowout behavior of lifted flames did not appear to be significantly affected by a change in the nozzle shape as long as the discharge area remained constant, but it was greatly affected by the fuel composition. In contrast, attached flame stability was influenced by both the fuel composition and the nozzle geometry which had the potential to extend the maximum co-flowing stream velocity without causing the flame to blow out. The parameters affecting the limiting stream velocity were studied.
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Kirsanov, Yu A., D. V. Makarushkin, and A. Yu Kirsanov. "INFLUENCE OF THE SWITCHING PERIODS FREQUENCY ON THE THERMAL EMISSIVITY OF A REGENERATIVE AIR PREHEATER." Proceedings of the higher educational institutions. ENERGY SECTOR PROBLEMS 20, no. 7-8 (September 8, 2018): 35–46. http://dx.doi.org/10.30724/1998-9903-2018-20-7-8-35-46.
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A laboratory stand with a regenerative air preheater, an automated control system and measurement of airflow parameters and a nozzle designed to study the heat transfer of a packet of parallel plates under non-stationary conditions for different periods is described. The technique of measuring the unsteady temperature of cold and hot coolant flows adjusted for inertia of the thermocouples and the method of measuring the heat transfer co efficient of plates. The time variations of the Nusselt number and the heat load transmitted by the nozzle for individual periods are shown. Obtained in experiments with the packages of plates of different materials and thickness values of the average Nusselt number for the period criterial generalized equation for convenient engineering calculations RAPH with leaf nozzles of various types.
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Lee, Cheolwoo, Insu Kim, and Junggoo Hong. "Experimental Investigation of Air–Fuel Mixing Effects on Flame Characteristics in a Direct fired Burner." Energies 14, no. 12 (June 15, 2021): 3552. http://dx.doi.org/10.3390/en14123552.
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The length and pattern of air–fuel mixing plays a significant role in the uniformity, flame temperature, and emission characteristics, which can lead to a superior product quality in a non-oxidizing direct fired burner for a cold-rolled steel plate furnace. In this study, a diffusion-flame-type burner and partially-premixed-type burner were experimentally investigated to understand their effects on flame shape, flame temperature, and exhaust gas characteristics. With this aim, fuel nozzle size, nozzle hole number, fuel injection angle, and mixing distance of fuel and air were varied during the experiments. Computational fluid dynamics simulations were also performed to investigate the air–fuel mixing state for a nozzle-mixed burner and a partially-premixed burner. The results show that the flame temperature of the partially-premixed burner increases by up to 26 °C on average compared to that of the nozzle-mixed burner. It is also shown that the mixing distance plays an important role in the flame temperature of the partially-premixed burner. In addition, the residual oxygen concentration and volume ratio of CO/CO2 in the flue gas of the partially-premixed burner exhibit lower concentrations compared to those of the diffusion flame burner.
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Lambosi, Latip, Amir Khalid, Bukhari Manshoor, Shahrin Hisyam, and Lo Kok Hao. "Effect of Nozzle Angle to Combustion Characteristic in Biodiesel Burner." Applied Mechanics and Materials 773-774 (July 2015): 585–89. http://dx.doi.org/10.4028/www.scientific.net/amm.773-774.585.
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The increasing effort on the environmental impacts of fossil fuel based power generation has led to increased research with the aim of reducing emissions and improving combustion efficiency by turning to alternative fuel such as biodiesel. But the hazardous emission caused by biodiesel is still a problem that need to tackle. One of way to achieve this is by choosing the correct nozzle characteristic. In the current study, the effect of nozzle angle on mixture formation and combustion characteristic are investigate using air-assisted fuel atomizing biodiesel burner. The nozzle angle that was used are θ = 450 and 500. The results show with nozzle 450 produce lower spray penetration, but higher spray angle and spray area compare to nozzle 500. The result are similar on flame development. For the emission characteristic, the Carbon Monoxide (CO) and Hydro Carbon (HC) emission had a strong reduction by using nozzle with 450 angle compare to 500 angle.
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Ghaem-Maghami, E., and H. Johari. "Concentration Field Measurements Within Isolated Turbulent Puffs." Journal of Fluids Engineering 129, no. 2 (July 6, 2006): 194–99. http://dx.doi.org/10.1115/1.2409348.
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The structure of passive scalar concentration field within isolated turbulent puffs was measured using the planar laser Mie scattering technique. Puffs were generated by injecting seeded air through a 5-mm-diameter nozzle into a chamber with a weak air co-flow. The injection time and volume was varied by the use of a fast-response solenoid valve. Puffs were examined in the range of 25–55 diameters downstream of the nozzle. The Reynolds number based on the average velocity and nozzle diameter was 5000. The results indicate that as the injection volume increases, puffs evolve from a spherical geometry to that with a tail. The half-width of radial concentration profiles through the puff center decrease as the injection volume increases. On the other hand, the puff length in the axial direction increases with the injection volume. The volume of ambient fluid entrained by the puff, and normalized by the injected volume, decreases with increasing injection volume.
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Rao, A. K., C. H. Melcher, R. P. Wilson, E. N. Balles, F. S. Schaub, and J. A. Kimberley. "Operating Results of the Cooper-Bessemer JS-1 Engine on Coal–Water Slurry." Journal of Engineering for Gas Turbines and Power 110, no. 3 (July 1, 1988): 431–36. http://dx.doi.org/10.1115/1.3240139.
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Successful operation of the Cooper-Bessemer JS-1 engine on coal–water slurry (CWS) fuel has been achieved at full power output, part load, and part speed conditions with varying degrees of diesel pilot fuel including zero pilot (auto-ignition of CWS). Selected results of the effect of pilot fuel quantity, pilot fuel timing, and manifold air temperature on engine performance are presented. Also, the influence of injector nozzle hole size and CWS mean particle size on engine performance is studied. High injection pressures resulted in good atomization of CWS and in combination with heated combustion air resulted in short ignition delays and very acceptable fuel consumption. Low CO/CO2 ratios in exhaust gas analysis confirmed good combustion efficiency. NOx emissions are compared for CWS and diesel fuel operation of the engine. Effect of injector nozzle hole size and manifold air temperature on NOx emissions is studied.
8
Madanahalli, A. V., and S. R. Gollahalli. "Effects of Nozzle Orientation on the Structure and Emissions of Spray Flames." Journal of Energy Resources Technology 115, no. 3 (September 1, 1993): 183–89. http://dx.doi.org/10.1115/1.2905991.
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An experimental study of the effects of the orientation of the liquid fuel stream relative to the air stream from a twin fluid atomizer located in an open-jet wind tunnel is presented. The orientation angle was set at 0 (concurrent), 45, 90, 135, and 180 deg (directly opposed). At 45 and 90 deg, the flame length, the radiation emission, and the concentrations of carbon monoxide, carbon dioxide, nitric oxide, and soot are higher than those at co-flow conditions. At 135 deg, all these quantities decrease markedly from their values at 90 deg and again increase when the fuel and air streams are directly opposed (180 deg). These changes are discussed in terms of the influx of air and recirculation of combustion products into the salient zones of the flame.
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Stapper, B. E., W. A. Sowa, and G. S. Samuelsen. "An Experimental Study of the Effects of Liquid Properties on the Breakup of a Two-Dimensional Liquid Sheet." Journal of Engineering for Gas Turbines and Power 114, no. 1 (January 1, 1992): 39–45. http://dx.doi.org/10.1115/1.2906305.
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The breakup of a liquid sheet is of fundamental interest in the atomization of liquid fuels. The present study explores the breakup of a two-dimensional liquid sheet in the presence of co-flow air with emphasis on the extent to which liquid properties affect breakup. Three liquids, selected with varying values of viscosity and surface tension, are introduced through a twin-fluid, two-dimensional nozzle. A pulsed laser imaging system is used to determine the sheet structure at breakup, the distance and time to breakup, and the character of the ligaments and droplets formed. Experiments are conducted at two liquid flow rates with five flow rates of co-flowing air. Liquid properties affect the residence time required to initiate sheet breakup, and alter the time and length scales in the breakup mechanism.
10
Uchiyama, Tomomi, and Akihito Fukase. "Three-Dimensional Vortex Method for Gas-Particle Two-Phase Compound Round Jet." Journal of Fluids Engineering 127, no. 1 (January 1, 2005): 32–40. http://dx.doi.org/10.1115/1.1852490.
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This paper proposes a three-dimensional vortex method for a gas-particle two-phase compound round jet. The method can take account of the interaction between the two phases by calculating the motion of particles and the behavior of gas vortex elements through the Lagrangian approach. In order to discuss the validity of the method, an air jet, loaded with small glass particles, issuing from a round nozzle into the co-flowing air stream is simulated. The simulation demonstrates that the air turbulence modulations due to the particles, such as the relaxation of velocity decay, the decrement of momentum diffusion in the radial direction at the fully developed region, and the reduction of turbulent intensity and Reynolds shear stress, are successfully captured by the method.
11
Ozaki, Hitoshi, Takahito Mima, Hiroshi Kawakami, and Jippei Suzuki. "Cutting Properties of Austenitic Stainless Steel by Using Linear Polarized CO2 Laser without Assist Gas." Materials Science Forum 706-709 (January 2012): 2228–33. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.2228.
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Recently, laser cutting is used in many industries. Generally, in laser cutting of metallic materials, assist gas and its nozzle are needed to remove the molten metal. However, because of the gas nozzle should be moved closer to the position about 1 mm from the surface of a workpiece, it is thought that existence of the nozzle causes lack of flexibility of laser cutting. Therefore, the new cutting process, Assist Gas Free laser cutting (hereafter, called as AGF laser cutting), has been developed and investigated about cutting properties in our laboratory. In this process, the pressure at the bottom side of a workpiece is reduced by a vacuum pump, and the molten metal can be removed by the air flow caused by the pressure difference between both sides of the specimen. On the other hand, when cutting of metallic materials with a linear polarized laser is performed, it is known that the cutting kerf might slant. This phenomenon is also observed in AGF laser cutting. In the present study, cutting properties of austenitic stainless steel by using liner polarized CO2 laser in AGF laser cutting was investigated. Cutting speed and direction were varied in order to study the effect of these parameters on cutting properties. As a result, when the angle formed by the cutting direction and the polarized direction of laser was parallel, the kerf slant could be depressed, and the critical cutting speed could be the fastest in any other cutting direction.
12
Eades, Andrew, and W. J. Brignall. "Counter-current dissolved air flotation/filtration." Water Science and Technology 31, no. 3-4 (February 1, 1995): 173–78. http://dx.doi.org/10.2166/wst.1995.0527.
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Thames Water Utilities has developed and patented a Counter-current dissolved air flotation/filtration (COCO-DAFF) process as a compact water treatment system designed to remove particulate material from traditional water sources. In particular it has been developed to overcome operational problems with primary filters caused by seasonal blooms of filter blocking algae such as Melosira sp., Aphanizomenon sp. andAnabaena sp. The process can be run without flotation during periods when algae are not a problem, giving operational cost savings. This process differs from co-current dissolved air flotation in that the recycle water is introduced after the inlet structure, but above the filter media. This generates an even depth bubble blanket in the flotation tank through which all the flocculated water must pass. The advantages are that in moving the recycle inlet away from the flocculated water inlet the potential for floc damage by the recycle is eliminated. Also since the entire sludge blanket is supported by a deep, even, bubble blanket, on de-sludging any fall-out of sludge that occurs near the de-sludging weirs will have to go back down through the process, leading to subsequent re-floating, and a reduced potential for spiking of the floated turbidity. Process validation experiments have been carried out on a 1.4 Ml/d pilot plant based at the Kempton Advanced Water Treatment Centre, London. These tests have identified a required flocculation time of 15 minutes prior to counter-current flotation, and insensitivity to the depth of the air injection below top water level. Dissolved air distribution is achieved using a special high volume flow rate DAF nozzle designed to lower the number of nozzles required per unit area, and to maximise the spread of the bubble cloud for optimum bubble/particle contact. Computational fluid dynamics (CFD) has been used in the scale-up of the pilot plant experience into the first full scale of this design plant to be built, by PWT Projects, at the 200 Ml/d Walton AWTW, for Thames Water Utilities.
13
Banazadeh, Afshin, and Farzad Banazadeh. "A Computational and Analytical Study into the Use of Counter-Flow Fluidic Thrust Vectoring Nozzle for Small Gas Turbine Engines." Applied Mechanics and Materials 629 (October 2014): 97–103. http://dx.doi.org/10.4028/www.scientific.net/amm.629.97.
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This paper provides an understanding of counter-flow fluidic thrust vectoring, in the presence of the secondary air vacuum, applied to the exhaust nozzle of a micro-jet engine. An analytical and numerical study is performed here on a divergent collar surface adjacent to the cylindrical exhaust duct system. The vectoring angle is controlled by manipulating the momentum flux through a vacuum gap that is located on a circle concentric to the main nozzle. Three dimensional numerical simulations are conducted by utilizing a computational fluid dynamics model with two-equation standard k-ε turbulence model to study the pressure and velocity distribution of internal flow and nozzle geometry. Moreover, an analytical validation is carried out based on the known mathematical form of the governing equations of fluid dynamics over the sinusoidal wall. It is shown that the analytical results are in good agreement with numerical simulations, which also show that the pressure coefficient over the collar surface has the same trend as given by computational simulation. Similarly, the results of the numerical method are also verified against experimental results that were approved by previous research in area of numerical model for co-flow fluidic thrust vectoring technique.
14
Mahmud, T., J. S. Truelove, and T. F. Wall. "Flow Characteristics of Swirling Coaxial Jets From Divergent Nozzles." Journal of Fluids Engineering 109, no. 3 (September 1, 1987): 275–82. http://dx.doi.org/10.1115/1.3242661.
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The aerodynamic characteristics of free, swirling, coaxial jets issuing from an air model of a typical burner for pulverized bituminous coal have been studied. Detailed measurements of mean velocity and static pressure have been obtained in the region near the nozzle exit. The boundary of the reverse-flow zone has been mapped and the recirculated-mass flowrate measured in order to quantify the effects of velocity ratio and swirl in the primary and secondary jets. The influence of burner geometry (divergent-nozzle length and centre-line blockage) has also been studied. The type of flow pattern is found to depend upon the level of swirl in the primary and secondary jets. The recirculated-mass flowrate is predominantly influenced by secondary swirl. The measurements have been compared with predictions obtained by numerical solution of the governing conservation equations in orthogonal curvilinear co-ordinates. The general features of the flows are adequately predicted although discrepancies in detail seem to indicate deficiencies in the turbulence model.
15
Zebbiche, T. "Stagnation pressure effect on the supersonic minimum length nozzle design." Aeronautical Journal 123, no. 1265 (June 19, 2019): 1013–31. http://dx.doi.org/10.1017/aer.2019.42.
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ABSTRACTThe aim of this work is to develop a calculation model based on the method of characteristics making it possible to study the effect of the stagnation pressure of the combustion chamber on the 2D and axisymmetric minimum length nozzle design giving a uniform and parallel flow at the exit section. The model is based on the use of the real gas approach. The co-volume and the intermolecular interaction effect are taken into account by the use of the Berthelot state equation. The effect of molecular vibration is considered in our model to evaluate the behaviour of gas at a high temperature. In this case, the stagnation pressure and the stagnation temperature are important parameters in our model. The resolution of the algebraic equations is done by the finite difference corrector predictor algorithm. The validation of the results is controlled by the convergence of the critical section ratios calculated numerically as obtained by the theory. The mass and the thrust are evaluated to improve the efficiency of the nozzle. The comparison is made with the high temperature and perfect gas models. The application is made for air.
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Musavi, Zahra, Henrik Kusar, Robert Andersson, and Klas Engvall. "Modelling and Optimization of a Small Diesel Burner for Mobile Applications." Energies 11, no. 11 (October 25, 2018): 2904. http://dx.doi.org/10.3390/en11112904.
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While extensive research has been done on improving diesel engines, much less has been done on auxiliary heaters, which have their own design challenges. The study analyzes how to optimize the combustion performance of an auxiliary heater, a 6 kW diesel burner, by investigating key parameters affecting diesel combustion and their properties. A model of a small diesel heater, including a simulation of fuel injection and combustion process, was developed step-wise and verified against experimental results that can be used for scaling up to 25 kW heaters. The model was successfully applied to the burner, predicting the burner performance in comparison with experimental results. Three main variables were identified as important for the design. First, it was concluded that the distance from the ring cone to the nozzle is essential for the fluid dynamics and flame location, and that the ring cone should be moved closer to the nozzle for optimal performance. Second, the design of the swirl co-flow is important, and the swirl number of the inlet air should be kept above 0.6 to stabilize the flame location for the present burner design. Finally, the importance of the nozzle diameter to avoid divergent particle vaporization was pointed out.
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Mardani, Amir, and Sadegh Tabejamaat. "Numerical study of flame structure in the mild combustion regime." Thermal Science 19, no. 1 (2015): 21–34. http://dx.doi.org/10.2298/tsci120522091m.
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In this paper, turbulent non-premixed CH4+H2 jet flame issuing into a hot and diluted co-flow air is studied numerically. This flame is under condition of the moderate or intense low-oxygen dilution (MILD) combustion regime and related to published experimental data. The modelling is carried out using the EDC model to describe turbulence-chemistry interaction. The DRM-22 reduced mechanism and the GRI2.11 full mechanism are used to represent the chemical reactions of H2/methane jet flame. The flame structure for various O2 levels and jet Reynolds numbers are investigated. The results show that the flame entrainment increases by a decrease in O2 concentration at air side or jet Reynolds number. Local extinction is seen in the upstream and close to the fuel injection nozzle at the shear layer. It leads to the higher flame entertainment in MILD regime. The turbulence kinetic energy decay at centre line of jet decreases by an increase in O2 concentration at hot Co-flow. Also, increase in jet Reynolds or O2 level increases the mixing rate and rate of reactions.
18
Cranshaw, Whitney, D. Casey Sclar, Aaron Spriggs, and Jason Bishop. "Potato Insect Control, Ft. Collins, Co 1995." Arthropod Management Tests 21, no. 1 (January 1, 1996): 138. http://dx.doi.org/10.1093/amt/21.1.138.
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Abstract Plots were established at the Department of Horticulture Field Research Center; north of Ft. Collins, CO. Planting was done 12 May, establishing a series of 2-row plots, 30-ft in length. Plot design was a RCB with 4 replications. Admire applications were made to the soil along the sides of the hills and incorporated to a depth of 1-2 inches with a hand cultivator on 5 June, shortly after plant emergence. Soil applications of Granusol Magnesium were applied and incorporated into the hill on 24 June and 24 July. All foliar treatments were applied 27 June and 14 July (immediately after plot evaluations) using a CO2 compressed air sprayer with a single flat fan nozzle delivering 20 gal gal/acre at 45 psi in a series of passes that covered the top and both sides of each row. At the time of original treatment Colorado potato beetle mating and egg laying was common, with some recently hatched larvae present. Evaluations of Colorado potato beetle (CPB) larvae were made 30 June and 13 July by counting all larvae on the center 20-ft of each row. Populations dropped sharply after this point, preventing subsequent sampling. Potato flea beetle samples were taken on 4 dates, making 6 sweeps row (12 sweeps/plot) on the first two samples and 8 sweeps/plot on the subsequent samples. Green peach aphid and potato/tomato psyllid were enumerated by counting insects on 35 leaves per plot.
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Bhargava, Anuj, Med Colket, William Sowa, Kent Casleton, and Dan Maloney. "An Experimental and Modeling Study of Humid Air Premixed Flames." Journal of Engineering for Gas Turbines and Power 122, no. 3 (May 15, 2000): 405–11. http://dx.doi.org/10.1115/1.1286921.
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An experimental and modeling study has been performed jointly by UTRC and DOE-FETC to determine the effect of humidity in the combustion air on emissions and stability limits of gas turbine premixed flames. This study focuses on developing gas turbine combustor design criteria for the Humid Air Turbine (HAT) cycle. The experiments were conducted at different moisture levels (0 percent, 5 percent, 10 percent, and 15 percent by mass in the air), at a total pressure of 200 psi, pilot levels (0 percent, 1 percent, 3 percent, and 5 percent total fuel), and equivalence ratio (0.4 to 0.8 depending on the moisture levels). The moisture levels were achieved by injecting steam into dry air well upstream of the fuel-air premixing nozzle. Computations were made for comparison to the experiments using GRI Mech 2.11 kinetics and thermodynamic database for modeling the flame chemistry. A Perfectly Stirred Reactor (PSR) network code was used to create a network of PSRs to simulate the flame. Excellent agreement between the measured and modeled NOx (5–10 percent) was obtained. Trends of added moisture reducing NOx and the effects of equivalence ratio and piloting level were well predicted. The CO predictions were higher by about 30–50 percent. The CO discrepancies are attributed to in-probe oxidation. The agreement between the data and model predictions over a wide range of conditions indicate the consistency and reliability of the measured data and usefulness of the modeling approach. An analysis of NOx formation revealed that at constant equilibrium temperature, Teq, the presence of steam leads to lower O-atom concentration which reduces “Zeldovich and N2O” NOx while higher OH-atom concentration reduces “Fenimore” NOx.[S0742-4795(00)00703-1]
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Hemanandh, J., and K. V. Narayanan. "Experimental Studies of Emissions in a CI Engine Blended with Refined Palmolein Oil." Advanced Materials Research 773 (September 2013): 165–70. http://dx.doi.org/10.4028/www.scientific.net/amr.773.165.
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In this study, the emissions from Kirloskar Direct Injection 4-stroke Diesel engine, single cylinder air-cooled, 4.4 kW, constant speed at 1500 rpm, compression ratio 17.5:1, with different blends of diesel and Refined Palmolein oil has been analyzed. Methyl Esters of refined Palmolein was transesterified with animal fat before blending with diesel. The main objective of this study is to measure the CO, HC, NOx, Smoke Emissions by varying the Injection pressure and the load. The experiments were conducted with various blends of Refined Palmolein oil and diesel (10%+90% PD, 30%+ 70% PD, and 40%+ 60% PD) at different pressures (180 bar, 210 bar, & 240 bar) and at different loads (0%, 25%, 50%, 75%, 100%). A 3-hole nozzle was used to inject the fuel. The emissions results were studied using AVL gas analyzer. The results show that there is a decrease in HC and CO and also marginal increase in NOx with exhaust temperature
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Tseng, Yen Kuei. "To Gain the Burning Efficiency by Improving the Mixing Condition of Oil and Gas." Advanced Materials Research 361-363 (October 2011): 861–64. http://dx.doi.org/10.4028/www.scientific.net/amr.361-363.861.
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In this research, the burner used in current industry is modified to improve the state of mixture for air and oil, so that the burning efficiency could be promoted to save fuel as well as reduce emissions of waste gas and waste heat. The way of operating this modified burner was same as the traditional one by inducing the air and oil with high pressure to the furnace, then mixing and burning the compound inside the chamber. Moreover, the construction of this modified burner was a bit different with an extra device call spoiler, which will be fixed in front end of the nozzle to create a turbulent flow for better mixing of inlet air and oil, so as to increase the burning efficiency. As the cone shape spoiler is set up onto the burner, it will seperate the inlet oil and gas inside and outside the cone , when the oil is injected from the nozzle with a high speed flow, the air inside the cone will be brought out and form a low pressure zone, in this time, if some tiny holes are punched on the wall of the cone, the inlet air outside the cone will leak inside and create a turbulent flow, which can improve the mixing condition of oil and gas and gain burning efficiency. As with the standard burner used in industrial furnaces for testing, comparing the average fuel consumption for unit hour and contrast the emissions of burner with and without installing spoiler, one can find that, the energy saving can effectively reach to 15%，while the emissions of NOxand SOxwere at the utmost reduced by 13% and 9%, respectively. The measured data of CO, CO2and waste heat expelling to environment were keeping the same, but actually they were low down when considering the total volume of inlet air diminished by 10%. The above results show that, with the spoiler attached, the burning system will have obvious benefit for energy saving and emissions reducing, and that really fit the goal of nowadays’ situation to live without energy deficit and environment impact.
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Madadnia, Jafar, Deepak Kala, Dheerej Pillai, and Homa Koosha. "Design, Build and Testing of a Noise-Free Twin Shaft Co-Axial Wind Turbine for UTS Buildings." Advanced Materials Research 452-453 (January 2012): 1089–93. http://dx.doi.org/10.4028/www.scientific.net/amr.452-453.1089.
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Management and control of noise pollution in wind turbines are important to integrate wind turbines in building and urban areas. A scaled model of a horizontal-co-axial wind turbine was designed, built and tested in the wind tunnel of University of Technology Sydney (UTS) and its characteristics and aerodynamic-noise emissions were analyzed. The noise reduction capability of the horizontal-twin-shaft wind turbines was compared with wind turbines with the conical entry nozzle (stator), duct-shroud-envelop and vertical shafts. Air velocity, shaft rpm, electric-power generation, noise frequency and amplitude were measured. It was found that up to 15% reduction in the amplitude (dB) of noise emisit from twin shaft wind turbine compared to the single shaft bench mark turbine. The noise analysis performed as a result of these experiments may be used in the design and selection of a building integrated horizontal axis wind turbine for applications at UTS buildings.
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Lisiecki, A., D. Ślizak, and A. Kukofka. "Laser cladding of Co-based metallic powder at cryogenic conditions." Journal of Achievements in Materials and Manufacturing Engineering 1, no. 95 (July 2, 2019): 20–31. http://dx.doi.org/10.5604/01.3001.0013.7622.
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Purpose: of this paper was demonstration a novel technique of laser cladding by experimentally composed Co-based metallic powder and forced cooling of the substrate by liquid nitrogen under cryogenic conditions, at the temperature -190°C, for producing clad layers with enhanced microstructure characteristic and properties. Design/methodology/approach: Technological tests of laser cladding were conducted by means of a high power fibre laser HPFL with maximum output power 3.0 kW, and six-axis robot. The experimental Co-based powder was composed for providing high abrasive wear resistance, high resistance for impact load, and also for corrosion resistance at elevated temperature. The unique and novel technique of forced cooling of the substrate was provided by immersing the specimens in the liquid nitrogen bath. The three coaxial nozzle head was designed and custom made to provide precise deposition of the powder delivered into the laser beam irradiation region. The scope of the study included tests of conventional laser cladding at free cooling in ambient air in a wide range of processing parameters, and also trials of laser cladding under cryogenic conditions. The test clad layers produced by conventional laser cladding and by the novel technique of laser powder deposition under cryogenic conditions were investigated and compared. Findings: The obtained results indicate that the novel technique of forced cooling the substrate by liquid nitrogen bath provides lower penetration depth, as well as low dilution of the clad, and also provides higher hardness of the clads. Additionally, it is possible shaping the geometry of the individual bead, providing high reinforcement and low width. Research limitations/implications: The presented results are based just on preliminary test of the novel technique of laser cladding under cryogenic conditions. Therefore, further study and detailed analyse of the influence of the cooling rate on the quality, microstructure, and properties of the deposited coatings are required. Practical implications: The study is focused on practical application of the novel technique for manufacturing of wear resistance coatings characterised with enhanced performance compared to conventional range of application of the laser cladding. Originality/value: Novel technique of laser cladding at forced cooling under cryogenic conditions was demonstrated. The powder used for cladding trials was experimentally composed (not commercially available). The experimental stand custom made was used with custom made powder feeding rate, and also with custom made coaxial nozzle head.
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Banazadeh, A., F. Saghafi, M. Ghoreyshi, and P. Pilidis. "Experimental and computational investigation into the use of co-flow fluidic thrust vectoring on a small gas turbine." Aeronautical Journal 112, no. 1127 (January 2008): 17–25. http://dx.doi.org/10.1017/s0001924000001950.
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Abstract This paper presents the application of a relatively new technique of fluidic thrust-vectoring (FTV), named Co-flow, for a small gas-turbines. The performance is obtained via experiment and computational fluid dynamics (CFD). The effects of a few selected parameters including the engine throttle setting, the secondary air mass-flow rate and the secondary slot height upon thrust-vectoring performance are provided. Thrust vectoring performance is characterised by the ability of the system to deflect the engine thrust with respect to the delivered secondary air mass-flow rate. The experimental study was conducted under static conditions in an outdoor environment at Cranfield University workshop that was especially designed for this purpose. As part of this investigation, the system was modelled by CFD techniques, using Pointwise’s Gridgen software and the three-dimensional flow solver, Fluent. Also, Cranfield’s gas-turbine performance code (TurboMatch) was utilised to estimate boundary conditions for the CFD analysis with respect to the integrated nozzle. The presented technique is easy-to-use approach and offers better result for thrust-vectoring problems than previously published works. Experimental results do show the overall viability of the blowing slot mechanism as a means of vectoring the engine thrust, with the current configuration. Computational predictions are shown to be consistent with the experimental observations and make the CFD model a reliable tool for predicting Co-flow fluidic thrust-vectoring performance of similar systems.
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Feitelberg, Alan S., Michael D. Starkey, Richard B. Schiefer, Roointon E. Pavri, Matt Bender, John L. Booth, and Gordon R. Schmidt. "Performance of a Reduced NOx Diffusion Flame Combustor for the MS5002 Gas Turbine." Journal of Engineering for Gas Turbines and Power 122, no. 2 (January 3, 2000): 301–6. http://dx.doi.org/10.1115/1.483217.
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This paper describes a reduced NOx diffusion flame combustor that has been developed for the MS5002 gas turbine. Laboratory tests have shown that when firing with natural gas, without water or steam injection, NOx emissions from the new combustor are about 40 percent lower than NOx emissions from the standard MS5002 combustor. CO emissions are virtually unchanged at base load, but increase at part load conditions. The laboratory results were confirmed in 1997 by a commercial demonstration test at a British Petroleum site in Prudhoe Bay, Alaska. The standard MS5002 gas turbine is equipped with a conventional, swirl stabilized diffusion flame combustion system. The twelve standard combustors in an MS5002 turbine are cylindrical cans, approximately 27 cm (10.5 in.) in diameter and 112 cm (44 in.) long. A small, annular, vortex generator surrounds the single fuel nozzle that is centered at the inlet to each can. The walls of the cans are louvered for cooling, and contain an array of mixing and dilution holes that provide the air needed to complete combustion and dilute the burned gas to the desired turbine inlet temperature. The new, reduced NOx emissions combustor (referred to as a “lean head end,” or LHE, combustor) retains all of the key features of the conventional combustor; the only significant difference is the arrangement of the mixing and dilution holes in the cylindrical combustor can. By optimizing the number, diameter, and location of these holes, NOx emissions were substantially reduced. The materials of construction, fuel nozzle, and total combustor air flow were unchanged. The differences in NOx emissions between the standard and LHE combustors, as well as the variations in NOx emissions with firing temperature, were well correlated using turbulent flame length arguments. Details of this correlation are also presented. [S0742-4795(00)01602-1]
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Soroka, B. S., and V. V. Horupa. "Environmental Characteristics of Modern Systems of Domestic Use of Fuel. Part 2. Pollutants Formation by Natural Gas Combustion in Atmospheric Burners: Experimental Studies." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 63, no. 5 (October 13, 2020): 450–61. http://dx.doi.org/10.21122/1029-7448-2020-63-5-450-461.
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The Gas Institute of the National Academy of Sciences of Ukraine performs comprehensive studies of the formation of toxic emissions in the flame of atmospheric burners and beyond the visible burning cones (“rich” primary flame). The experiments are based on the proven significant content of harmful substances in the combustion products of gas fuel in household appliances and on direct contact of consumers with gas emissions during the operation of the stoves. A methodology for the experimental researches of the harmful emissions formation has been proposed while the computerized firing rig serving as the diagnostic facility has been developed for studying the combustion of hydrocarbon gases in the burners of household stoves. Carbon oxides CO and nitrogen oxides NO and NO2 are considered as toxic emissions, while the primary air excess coefficient and the heat load of the burner are considered as variable parameters. Under operating conditions of a gas stove, its variable characteristics are the gas pressure in front of the nozzle of the atmospheric burner and its thermal power. When optimizing the design of burners, the determinant value of the stability of burning, energy and environmental indicators of fuel combustion is the coefficient of excess of primary air λpr at a given gas pressure before the burner. The influence of this coefficient on the formation of CO, NO, NO2 is established, and the possibility of emissions with a high concentration of nitrogen dioxide is proved. Since the concentration of [NO] decreases with an increase in λpr, and the absolute level of [NO2] concentrations is not significantly affected by the value of λpr, it is determined that the proportion of [NO2] concentration in the [NOx] = [NO] + [NO2] compound increases with an increase in the primary air excess coefficient.
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Hannibal, Joseph T., Michael E. Williams, and Gary L. Jackson. "An inexpensive source of dolomite powder for use with airbrasive units." Journal of Paleontology 62, no. 2 (March 1988): 316. http://dx.doi.org/10.1017/s002233600003002x.
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In the past few years the Cleveland Museum of Natural History has received several inquiries as to our source of dolomite for use with S.S. White® industrial airbrasive units. We have been using inexpensive, “agricultural” dolomite with these units for several years. This source was “discovered” by testing of a wide variety of dolomite sources by Peter Kotulak, a former preparator at the Museum, under the direction of M.E.W. We are currently using OHSO® Pulverized Limestone, a kiln-dried dolomitic limestone recommended for agricultural, and lawn and garden, use. It is produced by the Ohio® Lime Co., of Woodville, Ohio. A 22.7 kg (50 pound) bag costs $2.25, and is available at building supply companies. The dolomite must be sieved and dried to prevent clogging of the unit's line and nozzle. We use a Ro-Tap® Testing Sieve Shaker to sieve the material, with #30 (595 micron), #60 (250 micron), and #100 (150 micron) U.S.A. standard testing sieves. An incandescent desk lamp can be placed over an open container of the sieved dolomite to keep it dry. Used powder may be re-sieved for reuse if desired.
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Zhu, Sheng, and Bin Shi Xu. "High-Performance Ceramic Coatings Sprayed via Novel Supersonic Plasma Spraying System." Key Engineering Materials 280-283 (February 2007): 1203–6. http://dx.doi.org/10.4028/www.scientific.net/kem.280-283.1203.
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A novel supersonic plasma spraying system was developed with a maximum power of 80 kW and a maximum working gas flow of 6 m3/h, at which gas and particle velocities of 2400 and 600 m/s can be achieved respectively. This paper deals with novel supersonic plasma spraying system design, the structure of novel supersonic plasma gun includes a special Laval nozzle as the single anode and inner powder supply, and the mechanisms of supersonic plasma jet as well as the effects on the sprayed particles. The spraying process parameters of several ceramic powders such as Al2O3, Cr2O3, ZrO2, Cr3C2 and Co-WC were optimized. The properties and microstructure of the sprayed ceramic coatings were investigated. Nano Al2O3-TiO2 ceramic coating sprayed by using novel supersonic plasma spraying was also studied. Novel supersonic plasma spraying improves greatly ceramic coatings quality compared with conventional air plasma spraying (Metco 9M), as well as it has lower energy and gas exhaustion compared with high power supersonic plasma spraying (Plazjet), which can spray high-performance ceramic coatings at low cost.
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Choi, Chonggun, Woo Sung Choi, Jun Hyuk Choi, Woo Jin Kim, and Donghoon Shin. "Reducing CO emissions through a secondary air nozzle retrofit based on the jet penetration factor and the momentum flux ratio of a commercial wood waste incinerator." Applied Thermal Engineering 118 (May 2017): 101–12. http://dx.doi.org/10.1016/j.applthermaleng.2017.02.068.
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SAKAKI, Kazuhiko, Hidenori MIYAJIMA, Masami KATO, Kazuto SATO, and Junya KITAMURA. "J043016 Effect of Spray Gun Nozzle Geometry on Mechanical Properties of WC-Cermet Coatings Prepared by High Velocity Air Fuel Spraying." Proceedings of Mechanical Engineering Congress, Japan 2013 (2013): _J043016–1—_J043016–4. http://dx.doi.org/10.1299/jsmemecj.2013._j043016-1.
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Magalhães, Roberto, Senhorinha Teixeira, Manuel Ferreira, and José Teixeira. "Influence of Plate Orifice in the Pre-Mixing of Gas-Powered Water Heaters." Proceedings 58, no. 1 (September 12, 2020): 17. http://dx.doi.org/10.3390/wef-06930.
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Amongst the various alternatives for hot water production for domestic use, instantaneous heaters are still widely used in many markets such as the Portuguese market. In this system, a gas boiler converts the chemical energy of the gas (Liquefied Petroleum Gas, Natural Gas) to a water stream, as it is used. The complexity of such devices ranges from those with a natural convection to those with full pre-mixing of the air-fuel. The tightening of the legislation targeting these appliances is promoting an increase in efficiency, pollutant emission reduction and an increase in the safety features. The purpose of this work was to test the thermal performance of a water heater prototype with 22 kW of nominal heat output, running on Propane. Changes were made to the plate with orifices that limit the air supply to the burner flutes, where the pre-mixture with the fuel is partially made. Four different plates with different orifice diameters were built and tested in real case scenarios, taking into special consideration the pollutant emission and the fuel consumption verified. From the results, it was concluded that the best configuration in terms of efficiency is the original one, followed by the “−0.5 mm” and “−1 mm” plates. On the other hand, the best plate in terms of CO emission was the “−1 mm” plate. Concerning the plates with larger diameters to the manufacturer’s original configuration, flame instability was verified as a result of the greater primary airflow. Under the same test conditions, it was noted that the introduction of a nozzle into the fan inlet led to the suction of a larger amount of air. Finally, it was also concluded that the reduction in the orifice diameters of the plates reduces the split of primary air, resulting in an increased pressure drop in the flutes and in the overall pressure drop of the system.
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Uchida, Noboru, and Hiroki Watanabe. "A new concept of actively controlled rate of diesel combustion (ACCORDIC): Part II—simultaneous improvements in brake thermal efficiency and heat loss with modified nozzles." International Journal of Engine Research 20, no. 1 (December 19, 2018): 34–45. http://dx.doi.org/10.1177/1468087418820472.
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A new diffusion-based combustion concept (named it as Actively Controlled Rate of Diesel Combustion) for the confirmation of brake thermal efficiency optimum heat release rate profile based on multiple fuel injectors has been investigated. The outstanding results are; it is possible to achieve desired heat release rate profile only by the independent control of injection timing and duration of three injectors installed to a cylinder. The optimum brake thermal efficiency was not achieved with the Otto-like cycle but with the Sabathe-like cycle as predicted by a zero-dimensional thermodynamic model. Furthermore, smoke emissions were concurrently reduced with NOx emissions by increasing fuel amount from the side injectors without any deterioration in CO and total hydrocarbon emissions. On the other hand, brake thermal efficiency itself was not so improved than expected, because of lower heat release in the late part of combustion and unexpected less heat loss reduction. To solve these issues, combustion visualization and numerical simulation analysis were carried out. The results suggested that the adjacent sprays with narrower angle from each side injector deteriorated air entrainment and mixture formation, which might also result in the deterioration in wall heat loss in the expansion stroke. To solve both issues simultaneously, modified nozzle to inject against the swirl from the side injectors was utilized and achieved an improvement in both brake thermal efficiency and heat loss. That is the interdependent and reciprocal control of in-cylinder flow and fuel injection will be one of the breakthrough technologies for current trade-offs by the temporal and spatial spray flame optimization. Furthermore, the nozzle having higher flow rate with less number of orifice was utilized for the side injectors. Even though the smoke emissions were not optimized yet, brake thermal efficiency was much improved with higher heat release rate in the late part of combustion.
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Feitelberg, A. S., V. E. Tangirala, R. A. Elliott, R. E. Pavri, and R. B. Schiefer. "Reduced NOx Diffusion Flame Combustors for Industrial Gas Turbines." Journal of Engineering for Gas Turbines and Power 123, no. 4 (October 1, 2000): 757–65. http://dx.doi.org/10.1115/1.1376722.
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This paper describes reduced NOx diffusion flame combustors that have been developed for both simple cycle and regenerative cycle MS3002 and MS5002 gas turbines. Laboratory tests have shown that when firing with natural gas, without water or steam injection, NOx emissions from the new combustors are about 40 percent lower than NOx emissions from the standard combustors. CO emissions are virtually unchanged at base load, but increase at part load conditions. Commercial demonstration tests have confirmed the laboratory results. The standard combustors on both the MS3002 and MS5002 gas turbine are cylindrical cans, approximately 10.5 inches (27 cm) in diameter. A single fuel nozzle is centered at the inlet to each can and produces a swirl stabilized diffusion flame. The walls of the cans are louvered for cooling, and contain an array of mixing and dilution holes that provide the air needed to complete combustion and dilute the burned gas to the desired turbine inlet temperature. The MS3002 turbine is equipped with six combustor cans, while the MS5002 turbine is equipped with twelve combustors. The new, reduced NOx emissions combustors (referred to as a “lean head end,” or LHE, combustors) retain all of the key features of the conventional combustors; the only major difference is the arrangement of the mixing and dilution holes in the cylindrical combustor cans. By optimizing the number, diameter, and location of these holes, NOx emissions can be reduced considerably. Minor changes are also sometimes made to the combustor cap. The materials of construction, pressure drop, and fuel nozzle are all unchanged. The differences in NOx emissions between the standard and LHE combustors, as well as the variations in NOx emissions with firing temperature, are well correlated using turbulent flame length arguments. Details of this correlation are presented.
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Spalart, Philippe R., Michael L. Shur, and Michael Kh Strelets. "Added Sound Sources in Jets; Theory and Simulation." International Journal of Aeroacoustics 8, no. 6 (August 2009): 511–34. http://dx.doi.org/10.1260/147547209789141515.
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The Large-Eddy Simulation (LES) system established over the last six years is reviewed in terms of its progress in accuracy and transition physics, and is then used to explore the transmission of noise from a known local source through a turbulent region, here the shear layer of a jet. For this, weak artificial monopole sources are added to an LES, and their sound tracked in detail both in the near-field and far-field. Sources are placed in the potential cores of the primary and secondary streams, as well as in the mixing layer and outside the jet with various locations relative to the observer, and different frequencies. Simple Ray Acoustics theory based on the mean flow field and assuming full conservation of wave action via the Blokhintsev equation is quite successful, both in terms of wave-fronts and sound level, even at a diameter Strouhal number St of only 0.5. The principal difference is that LES predicts a gradual cone of silence upstream, which theory does not. The abrupt downstream cones of silence agree. Thus, even crossing a mixing layer with a Mach 0.9 difference does not appear to alter the sound much. Cases with a dual nozzle and hot core stream return similar findings. This will be helpful when creating lower-order prediction tools, and correcting noise measurements made outside a co-flow.
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Hata, T. Y., A. H. Hara, and Ben K. S. Hu. "Efficacy of Insecticides Against Thrips on Dendrobium, Hi, 1994." Arthropod Management Tests 20, no. 1 (January 1, 1995): 295. http://dx.doi.org/10.1093/amt/20.1.295a.
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Abstract Tests were conducted from 14 Jul through 8 Sep 1994 on 8 year old orchid plants at a commercial dendrobium farm in Kailua-Kona. Plants were growing in 1.3 cm crushed basaltic rock under 30% polypropylene shade using standard cultural practices. Experimental plots measured 40 ft2 with 58 plants per plot arranged in a RCB with four blocks. Four weekly applications of insecticides were applied beginning 14 Jul and ending 4 Aug. A spreader-sticker (Ad-here, J. R. Simplot, Lanthrop, CA) was added to all foliar treatments, including the control, at a rate of 0.5 ml per liter solution. Insecticides were applied at 1,345 liters/ha using a backpack sprayer (Solo Inc., Newport News, VA) equipped with an 8004 Teejet nozzle (Spraying systems Co. Wheaton, IL) at 276 KPa. The control was sprayed with water. Treatment efficacy was evaluated by randomly harvesting 5 inflorescences weekly from each block. Blossoms were removed from the inflorescences, counted, and placed in Berlese funnels heated with a 60 watt incandescent light bulb. Thrips were collected in an 8:2:1:1 solution of ethanol, distilled H20, acetic acid and glycerin, and the number of nymphs and adults counted. Because the number of blossoms per inflorescences varied, thrips counts were adjusted to the number of thrips per blossom by dividing the total number of thrips recovered by the total number of blossoms. Data were transformed to log,0(x + 1) and analyzed by ANOVA.
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Mahmoud, Rihab, Mehdi Jangi, Florian Ries, Benoit Fiorina, Johannes Janicka, and Amsini Sadiki. "Combustion Characteristics of a Non-Premixed Oxy-Flame Applying a Hybrid Filtered Eulerian Stochastic Field/Flamelet Progress Variable Approach." Applied Sciences 9, no. 7 (March 29, 2019): 1320. http://dx.doi.org/10.3390/app9071320.
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The oxidation of methane under oxy-fuel combustion conditions with carbon capture is attractive and deserves huge interest towards reducing CO2 and NOx emissions. The current paper reports on the predictions and analysis of combustion characteristics of a turbulent oxy-methane non-premixed flame operating under highly diluted conditions of CO2 and H2 in oxidizer and fuel streams, respectively. These are achieved by applying a novel, well-designed numerical combustion model. The latter consists of a large eddy simulation (LES) extension of a recently suggested hybrid model in Reynolds averaging-based numerical simulation (RANS) context by the authors. It combines a transported joint scalar probability density function (T-PDF) following the Eulerian Stochastic Field methodology (ESF) on the one hand, and a flamelet progress variable (FPV) turbulent combustion model under consideration of detailed chemical reaction mechanism on the other hand. This novel hybrid ESF/FPV approach removes the weaknesses of the presumed-probability density function (P-PDF)-based FPV modeling, along with the solving of associated additional modeled transport equations while rendering the T-PDF computationally less affordable. First, the prediction capability of the LES hybrid ESF/FPV was appraised on the well-known air-piloted methane jet flame (Sandia Flame D). Then, it was assessed in analyzing the combustion properties of a non-premixed oxy-flame and in capturing the CO2 dilution effect on the oxy-fuel flame behavior. To this end, the so-called oxy-flame B3, already numerically investigated in a RANS context, was analyzed. Comparisons with experimental data in terms of temperature, scalar distributions, and scatter plots agree satisfactorily. Finally, the impact of generating the FPV chemistry table under condition of unity Lewis number, even with CO2 dilution, was investigated on the general prediction of the oxy-fuel flame structure, stability and emissions. In particular, it turns out that 68% molar percentage of CO2 leads to 0.39% of CO formation near the burner fuel nozzle and 0.62% at 10 dfuel above the nozzle.
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Baxendale, F. P., A. P. Weinhold, J. Schild, and T. Merrigan. "Spring Application of Conventional and Biorational Insecticides for Control of Sod Webworms, 1996." Arthropod Management Tests 22, no. 1 (January 1, 1997): 354–55. http://dx.doi.org/10.1093/amt/22.1.354a.
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Abstract Insecticides were evaluated for control of sod webworm larvae on a Kentucky bluegrass lawn at the Gering Cemetery, in Scotts Bluff County, Nebraska. The turf (80% Kentucky bluegrass, 20% perennial rye and tall fescue) was maintained at a mowing height of 2.5 inches. Thatch accumulation (finger compressed) in the plot area was 0.5 inch. Field conditions at the study site were: soil type, silt loam; soil organic matter, 2.3%; soil pH, 8.4. Weather conditions at the time of treatment were as follows: soil moisture 16% by wt; air temperature 70°F; soil temperature 62°F; relative humidity 29%; wind direction and velocity 157° at 11 mph. Plots were 7 x 7 ft and the experimental design was a RCB with 3 replications. Treatments were applied on 6 May. Liquid insecticides were applied using a CO, sprayer with a TeeJet® 8002 nozzle at 30 psi and delivering 2 gal finished spray/1000 ft2. Following applications, plots were irrigated with 0.125 inches of water. A total of 0.67 inch of rain fell during the post-treatment period. Treatments were evaluated 3,7, and 14 DAT (10, 14, and 21 May) by mixing 0.5 oz of Lemon Dawn® per gal of water and applying one gal of the dilution to each of two 6 ft sampling areas per plot (12.0 ft2 total area). Larvae that moved to the grass surface after twenty minutes, were collected and counted.
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Shaw, J. T., J. W. Finger, K. L. Steffey, and M. E. Gray. "Efficacy of Bt Corn Hybrids Compared to Pre-Plant, Planting-Time, Pre-Emergence, and Rescue Insec-Ticide Treatments for Black Cutworm Control, 1997." Arthropod Management Tests 23, no. 1 (January 1, 1998): 380–81. http://dx.doi.org/10.1093/amt/23.1.380.
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Abstract Each plot consisted of four rows by 40 feet long, with treatments applied tc the center two rows, leaving two untreated rows between each plot. A RCB design with four replications was used. Two untreated check plots were includec in each replication and were averaged for ANOVA. Fifteen third- to fourth-instar laboratory reared BCW larvae were placed in each barrier arena on 2’. May. Corn plants within each barrier were in the Vl-2 stage (Iowa State Special Report, No. 48), at the time of larval release. The larvae used in this tes were supplied by Dr. Armon Keaster and Mary Jackson of the University of Missouri. Pre-plant insecticide treatments were applied with a CO2 back-pack sprayer utilizing four 8003VS nozzles calibrated to deliver 18.7 gpa at 25 psi, broadcast over what would become the center two rows of the four-row plots Planting-time granular insecticides were metered through Noble units mounted on each of the center 2 planter units. These granules were applied in a 7-incl band ahead of the firming wheels on the planter. Spring tines mounted behind each planter unit were used to incorporate insecticides into the soil. Planting time microtube liquid treatments of (Regent 4SC 0.13 lb(AI)/acre and Regent 4SC 0.13 lb(AI)/acre + Pounce 3.2 EC 0.05 lb(AI)/acre) were applied usinj microtubes directed into the furrow and calibrated to deliver 1.0 gpa at 20 psi. Planting-time banded liquid treatments of (Regent 4 SC 0.13 lb (AI)/acre anc Regent 4 SC 0.13 lb (AI)/acre + Pounce 3.2 EC 0.05 lb (AI)/acre) were applied with two 80067 TeeJet nozzles (1 per row), in a 7-inch band, with a compressed-air system calibrated to deliver 3.3 gap at 16 psi and a speed of 2.5 mph. Pre-emergence insecticide treatments were applied with a CO, back-pack sprayer utilizing 4 8003VS nozzles calibrated to deliver 18.7 gpa at 25 psi, over the center two rows of the four-row plots. Rescue insecticide treatment; were applied utilizing the same equipment used for the pre-emergence treatments over the center two rows of the four-row plots.
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Way, M. O., and R. G. Wallace. "Control of Rice Water Weevil With Fipronil in A Drill-Seeded, Delayed Flood Culture–Eup Study, 1996." Arthropod Management Tests 22, no. 1 (January 1, 1997): 297. http://dx.doi.org/10.1093/amt/22.1.297.
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Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was a non-replicated experimental use permit (EUP) study with 4 treatments. Plot size was 3 acres. On 26 Mar, plots were fertilized by air with 55-40-0 at 56 lb nitrogen/acre. Fertilizer was in-corporated with a “Do-all” on the same day. On 27 Mar, a designated plot was treated with Fipronil 80 WG at 0.0325 lb (AI)/acre using a large (11 nozzle, tip size80015, 50 mesh screens), 2 person, hand-held spray boom pressurized with CO2. Final spray volume was 10.6 gpa. Following application, the treatment was incorporated with a spike-tooth harrow. On 27 Mar, plots were drill-planted (7.5 inches between rows) with fipronil-treated or untreated seed at 90 lb/acre. Seed was treated with fipronil at 0.0325 lb (AI)/ cwt seed. All seed was provided by Rhone-Poulenc Ag Company which obtained untreated, registered seed from G&H Seed Co., Inc., Crowley, LA. Plots were “rolled” after planting to help cover seed and to create a firm seedbed. Plots were flush irrigated (temporary flood for 24th, then drain) on 5 Apr. Rice emerged 15 Apr. No differences in emergence were detected among the plots. From emergence to application of the permanent flood onl6May(31d after rice emergence), rice was flush irrigated as needed. On 24 Apr, plots were treated by air with Stam 4E and Basagran at 3 qt and 1 pt/acre, respectively. On 9 May, plots were fertilized by air with urea at 55 lb nitrogen/acre. Furdan 3G at 0.5 lb (AI)/acre was applied by air to the designated plot on 30 May (14 d after application of the permanent flood). On each of 5 Jun and 24 Jun (20 and 39 d after application of the permanent flood), twenty 4 inch diam X 4 inch deep soil cores were removed (each core containing at least 1 rice plant) from each plot. Rice plants in cores were washed and immature RWW recovered from the roots. On 3 Jun, plots were fertilized with urea at 60 lb nitrogen/acre; thus, total nitrogen applied to the plots for the growing season was 171 lb/acre. All aerial applications were made by M&M Air Service of Beaumont, TX. Plots were not harvested due to mechanical and weather problems. Insect counts were transformed using x + 0.5 and analyzed by 1 -way ANOVA and LSD.
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Siregar, Kiman, Rizal Alamsyah, Ichwana Ichwana, Sholihati Sholihati, and Saminuddin B. Tou. "The Design of Power Plant Biomass in Isolated Are From National Electricty Company in Indonesia With Aplication of Tar Wet Scrubber and Filter Gas." Rona Teknik Pertanian 10, no. 2 (October 1, 2017): 64–77. http://dx.doi.org/10.17969/rtp.v10i2.10007.
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Abstrak. Mesin gasifikasi bertujuan untuk menghasilkan gas mampu bakar (CO, H2, CH4). Gas mampu bakar yang dihasilkan dapat digunakan untuk menggantikan fossil fuel untuk menjalankan gas engine. Namun gas mampu bakar yang dihasilkan tersebut mengandung tar (kotoran) yang masih tinggi, sehingga terjadi pengotoran filter engine dan mengakibatkan mesin tidak dapat dioperasikan dalam waktu yang cukup lama. Penelitian ini bertujuan untuk mendisain Mesin Pembangkit Listrik Tenaga Biomassa (PLTBm) pada daerah terisolasi dari jaringan listrik PT.PLN (Persero) di Indonesia melalui aplikasi tar wet scrubber dan gas filter. Mesin gasifier yang dirancang berupa tipe downdraft dengan kapasitas terpasang 25 kW. Tambahan komponen rangkaian PLTBm yang dirancang adalah tar wet scrubber, gas filter dan gas engine. Secara keseluruhan mesin PLTBm yang dirancang terdiri dari : (1)Tangki pengisian biomassa, (2)Tangki biomassa, (3)Reaktor tipe downdraft, (4)Cyclon, (5)Tar wet schrubber, (6)Water tank, (7)Gas filter, (8)Blower, (9)Gas engine kapasitas 25 kW, (10)Air inlet nozzle, (11)Connection pipe, (12)Termometer indicator, (13)Exhaust gas, (14)Pressure indicator. Pengurangan nilai tar selain menggunakan karbon aktif, juga menggunakan sistem perangkap kotoran gas (wet scrubber). Gasifier yang digunakan pada penelitian ini memiliki diameter reaktor 900 mm dan tinggi 1000 mm. Cyclon memiliki diameter 580 mm dengan tinggi 1766 mm. Gas filter memiliki panjang 700 mm, tinggi 700 mm dan lebar 700 mm. Tar wet scrubber terdiri dari 5 tabung (diameter tabung 300 mm) yang terangkai satu dengan yang lainnya dengan tujuan untuk menangkap tar yang masih terkandung dalam gas mampu bakar yang dihasilkan dari reaktor gasifikasi dengan dimensi total yaitu lebar 1750 mm dan tinggi 1300 mm.
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Huang, Haiming, and Weijie Li. "Influence factors of methane-air counterflow diffusion flame." Thermal Science 21, no. 4 (2017): 1689–93. http://dx.doi.org/10.2298/tsci160506054h.
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This paper investigates the influences of pressures, velocities, and temperatures of gases at nozzles on the temperature of flame. Considering that temperature and species mass fractions are functions of axial co-ordinates, a quasi-1-D mathematic model in cylindrical co-ordinates for counterflow diffusion flame is built. The results show that the pressure, velocities, and temperatures of gases can affect the temperature distributions of methane-air counterflow diffusion flame, and that the influence of the variations of velocities at two nozzles on the movement of the starting reaction interface is most significant in these factors.
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Hu, Dong, Chuan Lin Tang, and Feng Hua Zhang. "The Effect of Air Injector on the Performance of Airlift." Advanced Materials Research 516-517 (May 2012): 1022–27. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.1022.
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In order to investigate the air injection method on the performance of an airlift. For this purpose an air lift system with a riser 2000 mm long and 80 mm in diameter, was designed and tested. Seven different air injection methods were used at a constant submergence. The experimental results showed a marked effect on the airlift performance when operated with different air injection methods. The arrangement of five nozzles gives the best performance, and the one nozzle is the worst. Although the injection angle has a little effect on the airlift performance, but view the general conclusions as a whole, the best lifting efficiency can be obtained when the angle of the nozzle placed along the tangential direction of pipe wall is equal to 10º at a given air flow rate QG =37m3/h.
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Maveety, J. G., and J. F. Hendricks. "A Heat Sink Performance Study Considering Material, Geometry, Nozzle Placement, and Reynolds Number With Air Impingement." Journal of Electronic Packaging 121, no. 3 (September 1, 1999): 156–61. http://dx.doi.org/10.1115/1.2792678.
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An impingement air flow heat sink performance study which considers the effects of geometry, nozzle-to-sink vertical placement, material and Reynolds number has been performed. The experiments consisted of varying the dimensionless nozzle-to-sink vertical distance from 2 to 12 and the Reynolds number from 1 × 104 to 5 × 104. A new carbon composite material manufactured by AlliedSignal was tested and shown to have superior heat transfer characteristics when compared to aluminum. The study also showed that optimal performance is achieved when the nozzle is placed within the dimensionless vertical distance of eight to twelve from the heat sink, and when the Reynolds number lies between 4 × 104 and 5 × 104. Both experimental and analytical estimates of the spreading resistance within the heat sinks tested were obtained.
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Hardalupas, Y., and J. H. Whitelaw. "Interaction Between Sprays From Multiple Coaxial Airblast Atomizers." Journal of Fluids Engineering 118, no. 4 (December 1, 1996): 762–71. http://dx.doi.org/10.1115/1.2835507.
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Phase Doppler measurements of size, velocity, liquid flux, and average mass fractions were obtained in sprays produced by three identical coaxial airblast atomizers, with their axes placed in a triangular arrangement at distances of two air jet diameters from each other; the arrangement simulates the spray interaction in the preburner of the space shuttle main engine with water and air respectively replacing the liquid oxygen and hydrogen of the preburner sprays. Each nozzle comprised a liquid jet with exit diameter of 2.3 mm centred in a 8.95 mm diameter air stream. Two liquid flowrates were examined, while the air flowrate was kept constant, resulting in Weber number at the exit of the nozzle around 1100, air-to-liquid momentum ratio 8.6 and 38, velocity ratio 24 and 51, mass flowrate ratio 0.35 and 0.75, liquid jet Reynolds number 10,000 and 21,000 and air jet Reynolds number around 108,000. The air flow characteristics were compared to the flow without liquid injection. Up to 10 air jet diameters from the nozzle exit, individual spray characteristics dominated and maximum Sauter mean diameters, typically around 150 μm, and liquid flux were observed on the geometrical axes of the nozzles. Spray merging was strong in the region between the nozzle axes, where the Sauter mean diameter reduced and the liquid flux and the mean and rms of the fluctuations of the axial velocity of the droplets and the air flow increased relative to the single spray. Downstream of 25 air jet diameters from the nozzle exit, the multiple sprays merged to a single spray-like flow produced by a nozzle located at the centre of the triangular region between the nozzle axes. Reduction of the liquid flowrate by 50 percent, improved atomization by 25 percent, shortened the axial distance from the nozzles where the individual spray characteristics disappeared by 30 percent and increased the air flow turbulence by 20 percent. Droplet coalescence was negligible for high liquid flowrates, but for reduced liquid flowrates coalescence became important and the Sauter mean diameter increased with the axial distance from the exit by around 15 percent. Spray merging increased the air flow turbulence and the local mass fraction distribution of the air in the region between the nozzle axes by around 50 and 40 percent respectively relative to the single sprays, resulting in a fuel rich region with increased gas flow turbulence which may influence the ignition process in the preburner of the space shuttle main engine.
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Bayer, Robert, Jiří Maxa, and Pavla Šabacká. "Energy Harvesting Using Thermocouple and Compressed Air." Sensors 21, no. 18 (September 9, 2021): 6031. http://dx.doi.org/10.3390/s21186031.
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In this paper, we describe the possibility of using the energy of a compressed air flow, where cryogenic temperatures are achieved within the flow behind the nozzle, when reaching a critical flow in order to maximize the energy gained. Compared to the energy of compressed air, the energy obtained thermoelectrically is negligible, but not zero. We are therefore primarily aiming to maximize the use of available energy sources. Behind the aperture separating regions with a pressure difference of several atmospheres, a supersonic flow with a large temperature drop develops. Based on the Seebeck effect, a thermocouple is placed in these low temperatures to create a thermoelectric voltage. This paper contains a mathematical-physical analysis for proper nozzle design, controlled gas expansion and ideal placement of a thermocouple within the flow for best utilization of the low temperature before a shockwave formation. If the gas flow passes through a perpendicular shockwave, the velocity drops sharply and the gas pressure rises, thereby increasing the temperature. In contrast, with a conical shockwave, such dramatic changes do not occur and the cooling effect is not impaired. This article also contains analyses for proper forming of the head shape of the thermocouple to avoid the formation of a detached shockwave, which causes temperature stagnation resulting in lower thermocouple cooling efficiency.
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Southern, P. Sterling, and Micou M. Browne. "Tobacco Budworm Control on Flue-Cured Tobacco with Foliar Insecticides, 1996." Arthropod Management Tests 22, no. 1 (January 1, 1997): 330. http://dx.doi.org/10.1093/amt/22.1.330.
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Abstract Flue-cured tobacco was planted on the James T. Smith farm in Wayne Co., NC on 23 Apr. Plots of 0.02 acre (4 rows X 57 ft) were separated laterally by a vacant 5th row and on each end by turn alleys of 16 ft. Treatments were established in a RCB design with 4 replications. Just prior to treatment, a moderate natural infestation of budworms was augmented by artificial infestation of 10 plants in each of the 1st and 3rd rows of each plot. A single 2-d old larva (from the colony maintained by the Dept. of Entomology, N.C. State University) was transferred from artificial diet to each plant. Larvae were placed into the bud to simulate an established infestation. Treatments were applied on 3 Jun using a tractor-mounted sprayer (with the exception of Dipel 10 G) pressurized by a roller pump powered by the tractor PTO. Spray was delivered through 3 solid-cone nozzles (TG-1, TG-2, TG-1) per row at 60 psi and 37.5 gpa. Treatments were applied between 2:50 pm and 5:00 pm EDT. Diatect was treated as a wettable powder and sprayed. Dipel 10G was applied by hand directly to the bud of each plant. Air temperature was approximately 80° F and winds were light to moderate (3-7 mph). All plants (excluding the first and last) in rows 1 and 3 were checked for budworm infestation on the day of treatment and 4 and 11 DAT. These plants were rated for budworm damage 15 DAT. Individual plants were examined and an estimate of leaf area lost to budworm feeding made. Damage was scored as follows: 0 = no damage; 1 = less than 1.0 leaf equivalent lost; 2 = 1.0 - 2.0 leaf equivalents; 3 = more than 2.0 leaf equivalents lost; 4 = plant topped by budworm feeding. Average damage ratings were calculated by plot. After harvest and curing, tobacco from each plot was weighed and graded by a government grader. Grades were converted to a quality index (1-100, 100 high). All variables were subjected to analysis of variance and treatment means compared (where appropriate) using an LSD test. Before analysis, the proportion of plants infested was transformed to the arcsine of square root of proportion. Data shown in the table are not transformed and proportion of plants infested is presented as percentage of plants infested.
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Bolat, Ali, and Ömer Baris Özlüoymak. "Evaluation of performances of different types of spray nozzles in site-specific pesticide spraying." Semina: Ciências Agrárias 41, no. 4 (May 13, 2020): 1199. http://dx.doi.org/10.5433/1679-0359.2020v41n4p1199.
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In recent years, site-specific spraying methods, which are capable of combining the image processing technologies with electronic and information technologies, have been started to be used in the weed control and target-oriented spraying. In this study, in addition to the site-specific spraying in laboratory conditions; a mobile spraying system, which can also perform broadcast application as a reference method, was set up. The spraying performance of the mobile system was tested for three different nozzle types (standard flat fan nozzle, cone nozzle, air induction nozzle) and at speeds of 0.48, 0.60, 0.72 and 0.84 km h-1. The mobile system was operated as both broadcast and site-specific for each nozzle type and travel speed. Three artificial weed samples were used at 75 cm intervals as sampling surfaces on the movement of the mobile system in the spraying operations; filter papers (FP) and water-sensitive papers (WSP) were placed behind them on the bars. While deposition values were measured with the filter papers, water-sensitive papers were used to measure the coverage rates. The spray distribution of the site-specific method in comparison with the reference method was investigated. According to the results, site-specific spraying applications did not cause any negative impact on depositions and coverage rates. The nearest results compared with the broadcast spraying were obtained with the air induction nozzle type at a speed of 0.48 km h-1 with a 60.5% deposition amount and 95.9% coverage rate.
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Zhang, A. M., X. J. Bai, J. Du, and X. S. Wu. "Stability of the magnetoresistance for NiO-containing Co/Cu/Co spin valves naturally placed in air." Applied Physics A 91, no. 4 (April 12, 2008): 671–74. http://dx.doi.org/10.1007/s00339-008-4504-4.
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Minko, V. A., N. S. Kobelev, V. M. Kretova, V. N. Kobelev, V. Yu Amelin, and A. D. Soloviev. "INNOVATIVE SOLUTIONS OF ADSORPTION CLEANING RECIRCULATING AIR FOR ELECTRIC TESTS OF ELECTRIC PRODUCT TESTS." Proceedings of the Southwest State University 22, no. 6 (March 27, 2019): 103–10. http://dx.doi.org/10.21869/2223-1560-2018-22-6-103-110.
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The purpose of the study of this work: to provide a scientific justification for the energy-saving device to maintain the normalized parameters of the recirculated air in special “clean” rooms, to derive formulas for calculating the adsorption material during the operation of the installation. The novelty of the constructive solution is protected and confirmed by patents of the Russian Federation for the invention. Methods. The volume of adsorbent determined by this method is placed in a tank with a recirculation loop, which includes: a cleaning unit nozzle, the inner surface of which is spring-loaded with a grid placed on the side of a moving air flow and a grid around the entire outlet section of the expanding nozzle. Spring-loaded mesh, placed on the side of a moving air flow, is made according to the profile of the velocity profile of the moving air flow, which is caused by the manifold speed impact on the adsorbent grains, horizontally arranged layers in order to level the absorbing capacity of silica gel KSM-5 throughout the drying device and use in the system recirculation of the air supplied by the fan leads to a probable entry of the vaporous mass of oil into the stream being cleaned, and the analysis of scientific and technical oh showed no literature data on the nature of such contaminants granular filter material, resulting in the need to study the penetration of the oil by volume adsorbent per cycle electrical testing of electronic devices in a heat chamber. Results. Based on the analysis of well-known foreign and domestic theoretical and experimental studies, there was no development related to vibration effects on the efficiency of adsorption drying of recirculated air for electrical thermal testing of electronic products. An adsorption unit has been developed with a horizontal arrangement of an adsorbing substance for treating air under conditions of vibration effects. Conclusion The installation developed by the authors passed laboratory and industrial tests at the Mayak plant of Kursk and was recommended for implementation as a resource-saving constructive solution protected by patents of the Russian Federation for invention. Keywords: special premises electrical testing of electronic products, recirculation circuit in the chamber for temperature testing - heat chamber, adsorption drying, transparent body of the drying device, oil contamination.
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Mishra, Dipti P., Sukanta K. Dash, and P. Anil Kishan. "Isothermal Jet Suction Through the Lateral Openings of a Cylindrical Funnel." Journal of Ship Research 54, no. 04 (December 1, 2010): 268–80. http://dx.doi.org/10.5957/jsr.2010.54.4.268.
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This paper discusses the computation of air entrainment in to the louvers of a cylindrical funnel as a result of a high-velocity isothermal air jet placed inside the funnel having different lengths of protrusion and different funnel diameters. The experimental setup consists of a cylindrical Perspex tube with circular louvers cut around it. The flow through the nozzle is measured with a rotameter, and the velocity at the cylinder outlet is measured with a hot wire anemometer. The numerical simulation is carried out by solving the conservation equations of mass and momentum for the funnel with a surrounding computational domain so that the suction can take place at the louver entry. The resulting equations have been solved numerically using finite volume technique in an unstructured grid employing eddy viscosity based two-equation k-e turbulence model of Fluent 6.3. It has been found from the experiment and the CFD computation that there exists an optimum funnel diameter for which the mass ingress into the funnel is highest, and also there exists an optimum protrusion length of the nozzle that entrains maximum air flow into the funnel. For isothermal air suction the mass ingress into the funnel does not depend on the inclination of the funnel, whereas for low velocity and high temperature of the nozzle fluid the mass ingress in to the funnel depends on the inclination of the funnel. After a critical nozzle velocity (Gr/Re2 < 0.5), the mass ingress into the funnel does not again depend on the inclination of the funnel. An approximate relation for the entrance length of a sucking pipe has also been developed from the present CFD solution. The original contribution of the paper is the setting of a computational methodology for computing various conditions of suction flow in to a funnel while having the numerical confidence by comparing the CFD result with a small-scale experimental measurement in the laboratory.