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Journal articles on the topic 'Nozzle radius'
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1
Osman, Manal, Suhaimi B. Hassan, and Khamaruzaman Wan Yusof. "Effect of Low Pressure on Irrigation Uniformity of Solid Set Sprinkler Irrigation System." Applied Mechanics and Materials 567 (June 2014): 26–31. http://dx.doi.org/10.4028/www.scientific.net/amm.567.26.
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The irrigation requires an efficient and effective method of water application to realize maximum return and conserve water resources. The low pressure sprinkler irrigation system is the most commonly used due to: its low energy cost, but the irrigation uniformity of this system is not constantly good because it is affecting by the design factors such as: nozzle type, nozzle diameter, operating pressure and spacing layout. But the most important factors are the operating pressure and nozzle diameter. In this study the effect of low pressure on the irrigation uniformity of the solid set sprinkler irrigation system was studied. Different low operating pressures (62, 82, 102 and122 kPa) were selected and different nozzle diameters (4, 5 and 7 mm) were used. The solid set layout was square (12 m between the sprinklers along the line and 12 m among the line). The catch-cans test was used to determine the uniformity coefficients such as: Christiansen’s coefficient of uniformity (CU), coefficient of variation (CV), distribution uniformity of low quarter (DUlq) and distribution uniformity of low half (DUlh). The distribution characteristics such as: throw radius and rotation speed were monitored. A comparison was made between the results obtained from different combination of operating pressures and nozzle diameters. The results of this study showed that, CU, DUlqand DUlhwere increased when the pressure increased for all the nozzles. The greater values of CU, DUlqand DUlhwere found with the combination of 7 mm nozzle diameter and 122 kPa. The coefficient of variation was increased when the pressure decreased for all the nozzles. The throw radius and rotation speed were increased gradually when the pressure increased. The throw radius was not significantly affected by the nozzle diameter while the rotation speed was more affected by the nozzle diameter.
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Flock, Andreas K., and Ali Gülhan. "Design of converging-diverging nozzles with constant-radius centerbody." CEAS Space Journal 12, no. 2 (November 15, 2019): 191–201. http://dx.doi.org/10.1007/s12567-019-00286-4.
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AbstractSeveral flow phenomena, such as recirculating wake flows or noise generation, occur in aerodynamic configurations with backward facing steps. In this context, subsonic nozzles with constant-radius centerbodies exist, which enable fundamental research of these phenomena for $$M < 1$$M<1. For the supersonic regime, however, the existing database and knowledge are limited. Therefore, this work presents a design approach for a converging-diverging nozzle with constant-radius centerbody. For the nozzle throat, Sauer’s method is modified to include a centerbody. The method of characteristics is used for the subsequent supersonic portion. Comparing the analytical calculations to numerical simulations results in very good agreement and therefore underlines the feasibility of the chosen approach. Viscosity reduced the Mach number on the exit plane by 1.0–1.2% and therefore had little influence.
3
Naderan-Tahan, K., and M. Robinson. "Plastic Limit Pressures for Neighbouring Radial Nozzles in a Spherical Pressure Vessel." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 210, no. 1 (February 1996): 75–78. http://dx.doi.org/10.1243/pime_proc_1996_210_295_02.
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Limit pressures have been calculated for the case of two identical flush neighbouring radial nozzles in a spherical pressure vessel. The nozzle and vessel radius and thickness have been kept fixed, but the separation angle 2α has been varied. Four cases have been analysed, including that where the nozzles touch, and the results compared to the value for a single nozzle. For these nozzles very little decrease occurred for any of the α. The effect of displacement on pressure carrying capacity was also investigated and shown to be beneficial, so that limit pressure results may be used with confidence.
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Tao, Y., W. Adler, and E. Specht. "Numerical analysis of multiple jets discharging into a confined cylindrical crossflow." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 216, no. 3 (August 1, 2002): 173–80. http://dx.doi.org/10.1243/095440802320225383.
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A row of jets discharging normally into a confined cylindrical crossflow is numerically investigated using the control-volume-based finite difference method. Interest is focused on determining the relationship between the temperature trajectory and the upstream flow and geometric variables. Parameter variations studied include nozzle diameter, number of nozzles, duct radius, jet and mainstream volume-flow, temperature ratio, and dynamic pressure ratio. The dynamic pressure ratio, the number of nozzles, and nozzle spacing are found to be significant variables. A logarithmic function describing the relationship between penetration depth and dynamic pressure divided by the square of the number of nozzles is derived by fitting the data of the computation results. The values for penetration depth and nozzle spacing are described for optimum mixing. A suggested design procedure is presented, which can be used as a first approach in configuration design.
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Mani, N., G. Thanigaiyarasu, and P. Chellapandi. "Parametric study of pull-out radius for steam generator shell nozzle junction for fast breeder reactor." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 227, no. 9 (November 23, 2012): 2129–39. http://dx.doi.org/10.1177/0954406212468544.
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This article presents the parametric study of pull-out radius of steam generator shell nozzle junction for fast breeder reactor. An efficient finite element modeling for shell nozzle junction has been presented in which shell elements are employed to idealize the whole region. In shell nozzle junction, pull-out region is an important part, so that region is taken and studied with different radius of curvature. The pull-out radius varies from 40 to 80 mm. Five models are taken into consideration and each with different radius of curvature. The optimized stress values for all the models are presented here.
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Mandrovskiy, K. P., and Ya S. Sadovnikova. "NUMERICAL RESEARCH OF QUALITY CHARACTERISTICS OF REAGENT DISTRIBUTION BY COMBINED ROAD MACHINE." Spravochnik. Inzhenernyi zhurnal, no. 279 (June 2020): 18–23. http://dx.doi.org/10.14489/hb.2020.06.pp.018-023.
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From the theory of aerohydrodynamics it is known that the design of hydraulic nozzles and the modes of their operation determine the nature of the distribution of droplets in space and the efficiency of the process. The subject of the research is the characteristics of the distribution quality of the liquid reagent, namely, the speed of dropping of droplets from the disk and the radius of the treatment zone formed by flying droplets on the coating. The question of the dispersion of the spray torch of a low-viscosity liquid, its role in the formation of the basic kinematic characteristics of moving drops, is considered. The article provides a numerical calculation and analysis of the effect of the dispersion of droplets of a distributed liquid (reagent) on the rate of dropping of droplets from a rotating disk and on the radius of the coating treatment zone. For research, two values of nozzle nozzle openings and a wide range of variation in the diameters of reagent droplets were selected. Based on the mathematical models previously developed by the authors of the process of dropping droplets from the nozzle and the movement of droplets in the air, implemented as part of a software product, the velocity of dropping of droplets from the nozzle nozzle and the rate of dropping of droplets from the disk at a given pressure were calculated. A cycle of calculations of the radius of the coating treatment zone was carried out with varying work and geometric characteristics of hydraulic equipment, providing high-quality and cost-effective implementation of the anti-icing reagent distribution process.
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Mandrovskiy, K. P., and Ya S. Sadovnikova. "NUMERICAL RESEARCH OF QUALITY CHARACTERISTICS OF REAGENT DISTRIBUTION BY COMBINED ROAD MACHINE." Spravochnik. Inzhenernyi zhurnal, no. 279 (June 2020): 18–23. http://dx.doi.org/10.14489/hb.2020.06.pp.018-023.
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From the theory of aerohydrodynamics it is known that the design of hydraulic nozzles and the modes of their operation determine the nature of the distribution of droplets in space and the efficiency of the process. The subject of the research is the characteristics of the distribution quality of the liquid reagent, namely, the speed of dropping of droplets from the disk and the radius of the treatment zone formed by flying droplets on the coating. The question of the dispersion of the spray torch of a low-viscosity liquid, its role in the formation of the basic kinematic characteristics of moving drops, is considered. The article provides a numerical calculation and analysis of the effect of the dispersion of droplets of a distributed liquid (reagent) on the rate of dropping of droplets from a rotating disk and on the radius of the coating treatment zone. For research, two values of nozzle nozzle openings and a wide range of variation in the diameters of reagent droplets were selected. Based on the mathematical models previously developed by the authors of the process of dropping droplets from the nozzle and the movement of droplets in the air, implemented as part of a software product, the velocity of dropping of droplets from the nozzle nozzle and the rate of dropping of droplets from the disk at a given pressure were calculated. A cycle of calculations of the radius of the coating treatment zone was carried out with varying work and geometric characteristics of hydraulic equipment, providing high-quality and cost-effective implementation of the anti-icing reagent distribution process.
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Hu, Yan, and Guo Xiu Li. "Injector Nozzle Multiphase Flow Numerical Simulation of High Pressure Common Rail System." Advanced Materials Research 1008-1009 (August 2014): 1006–10. http://dx.doi.org/10.4028/www.scientific.net/amr.1008-1009.1006.
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The changing of injector nozzle structure will influence the combustion and emission properties in diesel engine. Three-dimensional numerical simulation of multiphase flow of mini-sac nozzles of high pressure common rail were calculated by using the computational fluid dynamics ( CFD ) method in this paper. The results shown that this method can be more accurately obtained a lot of useful information on the flow field inside the nozzle in a relatively short period of time, and it is convenient for analysis and research the influence of geometry parameters on the flow characteristics inside the nozzle. The paper also studied the influence of nozzle inlet pressure, the angle between the axis of the hole and the axis of the injector and nozzle entrance radius to the flow characteristics inside the nozzle. It also studied the distribution of internal pressure, velocity of flow, gas-phase volume fraction and turbulent kinetic energy. These studies provided a favorable basis for the design and improvement of the nozzle structure and optimize combustion system matches.
9
Yin, Zhao-Qin, Dong-Sheng Li, Jin-Long Meng, and Ming Lou. "Discharge coefficient of small sonic nozzles." Thermal Science 18, no. 5 (2014): 1505–10. http://dx.doi.org/10.2298/tsci1405505y.
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The purpose of this investigation is to understand flow characteristics in mini/micro sonic nozzles, in order to precisely measure and control miniscule flowrates. Experimental and numerical simulation methods have been used to study critical flow Venturi nozzles. The results show that the nozzle?s size and shape influence gas flow characteristics which leading the boundary layer thickness to change, and then impact on the discharge coefficient. With the diameter of sonic nozzle throat decreasing, the discharge coefficient reduces. The maximum discharge coefficient exits in the condition of the inlet surface radius being double the throat diameter. The longer the diffuser section, the smaller the discharge coefficient becomes. Diffuser angle affects the discharge coefficient slightly.
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Dong, Fei, Shou Chen Xing, and Chen Hai Guo. "Numerical Simulation for Transient Flow of Field of Water Jet Based on Euler Method." Advanced Materials Research 694-697 (May 2013): 551–54. http://dx.doi.org/10.4028/www.scientific.net/amr.694-697.551.
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It is hard to accurately predict the shape and the characteristic of jet because of the dynamic characteristic of water jet in the atmosphere. The Eulerian model was used to calculate the water jet numerical simulation of two-phase flow. The distribution of the velocity, pressure and the component of the nozzle flow field were obtained under the condition of the initial pressure of nozzle is 100 MPa and the outlet diameter of nozzle is 0.2 mm. The results show that fluid velocity increases rapidly in the nozzle contraction section and appears the isokinetic core area after leaving the nozzle; the fluid dynamic pressure rapid rises in the nozzle contraction section and keeps invariant at the isokinetic core area; the ratio of the contraction flow radius and the nozzle radius is 7:10.
11
Ito, H., Y. Watanabe, and Y. Shoji. "A long-radius inlet nozzle for flow measurement." Journal of Physics E: Scientific Instruments 18, no. 1 (January 1985): 88–91. http://dx.doi.org/10.1088/0022-3735/18/1/021.
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Liu, Gaowen, Yuxin Liu, Xiaozhi Kong, and Qing Feng. "A new design of vane-shaped hole pre-swirl nozzle." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 231, no. 1 (November 11, 2016): 14–24. http://dx.doi.org/10.1177/0957650916673462.
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Theoretical analysis shows that the temperature drop of a pre-swirl system directly relates to the pre-swirl effectiveness of the pre-swirl nozzle. Besides, increasing the discharge coefficient and reducing the actual flow angle are the main ways to increase the pre-swirl effectiveness. A new design of pre-swirl nozzle called vane-shaped hole nozzle was introduced and analyzed in this paper. By keeping the throat area, the radial location and the pre-swirl angle (15°), numerical comparisons were carried out between the vane-shaped hole nozzle and other three typical nozzles, widely used in industry: simple drilled nozzle, aerodynamic nozzle and cascade vane nozzle. In order to involve the mixing and rotating effects in the pre-swirl cavity downstream of the nozzles, the rotating pre-swirl cavity and receiver hole were included in the computational models. Numerical results show that aerodynamic nozzle could alleviate the rapid acceleration and deflection at nozzle inlet, which results in 13.7% higher discharge coefficient than the simple drilled nozzle. The discharge coefficient of the cascade vane nozzle can be as high as 0.97 due to the aerodynamical design; however, the pre-swirl effectiveness is only 0.86 because of a large deviation angle (2.4°). For the vane-shaped hole nozzle, the vane height/pitch ratio could be flexibly adjusted to an appropriate value, which makes its performance better than that of the traditional ones. Higher vane height/pitch ratio and close to zero trailing edge radius lead to a small deviation angle (0.56°). Consequently, the pre-swirl effectiveness of the vane-shaped hole nozzle is about 8% higher than that of the cascade vane nozzle, though the discharge coefficient is about 5% lower. Additionally, the volume of the solid block in the vane-shaped hole nozzle is larger than that in the cascade vane nozzle, which could reduce the difficulty in manufacturing but increase the total weight.
13
Matusik, Katarzyna E., Daniel J. Duke, Alan L. Kastengren, Nicholas Sovis, Andrew B. Swantek, and Christopher F. Powell. "High-resolution X-ray tomography of Engine Combustion Network diesel injectors." International Journal of Engine Research 19, no. 9 (October 24, 2017): 963–76. http://dx.doi.org/10.1177/1468087417736985.
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The flow inside direct-injection diesel nozzles is strongly influenced by the local geometry. Deviations from the design geometry and nonuniformities along the fuel’s flow path can alter the expected spray behavior. The influence of small-scale variations in the internal geometry is not well understood due to a lack of data available to experimentalists and modelers that resolve such features. To address the need for more accurate geometry measurements that also quantify the error bounds on manufacturing variability, the 7-BM beamline of the Advanced Photon Source at Argonne National Laboratory has been customized to obtain high-resolution X-ray tomography of injection nozzles. In this article, we present results for several diesel injectors provided by the Engine Combustion Network. The imaging setup was optimized to measure dense metallic samples at high signal-to-noise ratio using projection imaging. To improve contrast, multiple images were recorded at each rotation angle. Phase shifting effects, which amplify the uncertainty in locating nozzle boundaries, were minimized by reducing the propagation distance of the X-rays between the nozzle and detector. Such improvements to the imaging technique enabled the nozzle hole diameter to be measured with an accuracy of 1.8 µm, which takes into account the pixel resolution as well as the properties of the imaging setup and the geometric analysis. The high spatial resolution allows the nozzle hole inlet corner radius to be azimuthally resolved. For the sample set under consideration, these new measurements reveal that non-hydroground injectors have a distribution of radii which typically vary by more than a factor of two. An azimuthally varying radius of curvature at the hole inlet is expected to result in highly asymmetric cavitation. Skeletal wireframe models of the nozzle hole geometries suitable for computational fluid dynamics mesh generation have been developed, in addition to full three-dimensional isosurfaces; these data have been made publicly available online.
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Zebbiche, Toufik. "Rapid design method and new contours for a class of three dimensional supersonic nozzle of arbitrary exit cross section." Mechanics & Industry 19, no. 4 (2018): 403. http://dx.doi.org/10.1051/meca/2018003.
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The aim of this work is to develop a new and rapid numerical method for designing a new contour of the supersonic nozzle with arbitrary exit cross sections as a class of three dimensional nozzle extracted from the calculation of stationary flow solutions in axisymmetric nozzle. The application is made for nozzle giving a uniform and parallel flow at the exit section. The determination of the points of the axisymmetric nozzle contours in a non-dimensional manner with respect to the arbitrary throat radius is necessary. The exit section of the nozzle must be discretized at several points. The radii of the points of the throat section are determined by equalizing the ratio of the axisymmetric critical sections corresponding to each selected point of the exit section. Each point passes a contour of the nozzle to the throat where their position is determined by the multiplication of the non-dimensional positions of the axisymmetric nozzle point by the throat radius of this contour. A uniform portion is added at the end of each contour to compensate the decrease in its length. Longitudinal discretization of the nozzle is necessary. The flow properties of each point are the same as those of the points of the axisymmetric nozzle. The temperature and the deviation of the flow at each point of any section are determined by their interpolations between two successive points of each contour. The Mach number, the pressure and the density are determined accordingly. The application is made for air at high temperature lower than the dissociation threshold of the molecules.
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Cai, Yu Kui, and Zhan Qiang Liu. "Micro Ball End Milling of Nickel-Based Alloy for Laval Nozzle." Materials Science Forum 800-801 (July 2014): 852–57. http://dx.doi.org/10.4028/www.scientific.net/msf.800-801.852.
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The performance of the micro nozzle is determined primarily by its machined surface topology and geometric profile. A circular cross-section micro-Laval nozzle is modeled and studied by using numerical simulation in this paper. The real residual height and residual area of machined nozzle surface with ball-end milling cutter are proposed. A micro-Laval nozzle was machined successfully. It is found that the ball end milling cutter with large radius is suitable for finishing operations in the viewpoint of nozzle performance. Moreover, the serial process of drilling and milling has been proved by experiments with which both high-level machining accuracy and performance can meet the nozzle requirement.
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Leu, M. C., P. Meng, E. S. Geskin, and L. Tismeneskiy. "Mathematical Modeling and Experimental Verification of Stationary Waterjet Cleaning Process." Journal of Manufacturing Science and Engineering 120, no. 3 (August 1, 1998): 571–79. http://dx.doi.org/10.1115/1.2830161.
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The use of stationary waterjet for the removal of coating material from the substrate is investigated analytically and experimentally. In the analysis, the cleaning width as a function of standoff distance, water pressure, and nozzle radius is derived by considering the structure of waterjet and the cleaning mechanism. Also derived are the relations of the optimal cleaning standoff distance and maximum cleaning width to the critical cleaning standoff distance, and how the water pressure and nozzle radius affect this critical standoff distance. These derived analytical relations are verified with experimental results.
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Meng, P., E. S. Geskin, M. C. Leu, F. Li, and L. Tismeneskiy. "An Analytical and Experimental Study of Cleaning With Moving Waterjets." Journal of Manufacturing Science and Engineering 120, no. 3 (August 1, 1998): 580–89. http://dx.doi.org/10.1115/1.2830162.
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A mathematical model of cleaning with moving waterjet is established by considering the structure of waterjet and applying Springer’s semi-empirical model on material erosion due to impact of water droplets. Based on this model, the cleaning width as a function of travel speed, standoff distance, water pressure, and nozzle radius is derived. Also derived is the relation of the critical cleaning standoff distance to travel speed, water pressure, and nozzle radius. The validity of the derived relations is verified by conducting moving waterjet experiments with varied cleaning system parameters.
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Abada, Omar, Abderahim Abada, and Ahmed Abdallah El-Hirtsi. "Effect of bipropellant combustion products on the rocket nozzle design." Mechanics & Industry 21, no. 5 (2020): 515. http://dx.doi.org/10.1051/meca/2020064.
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The focus of this research work is to investigate numerically the effect of adding the gas on the design and performance of axisymmetric MLN nozzles. A FORTRAN code was developed to design this nozzle using the characteristics method (MOC) at high temperature. The thermochemical and combustion studies of the most used liquid propellants on the satellites and launch vehicles allow to known all gases. Four engines are investigated: Ariane 5 (Vulcain 2), Ariane-5 upper stage engine (Aestus), Zenit first stage (RD-170) and Falcon 9 upper stage (Raptor). Thermodynamic analysis of parameters design MLN (such as length, Mach number, mass, thrust coefficient) was conducted. The comparison shows that the presence of 50% of H2O gas in combustion species increases the nozzle design parameters (diatomic gas including air) in the order of 25%. On the other hand, the existence of CO2 gas considerably increases approximately 35% the length and the exhaust radius. These rise depend on gases percentage in the combustion. The truncation method is applied in the MLN nozzles to optimize the thrust/weight ratio.
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Dodge, F. T., S. T. Green, and J. E. Johnson. "Characterization of Injection Nozzles for Gas-Solid Flow Applications." Journal of Fluids Engineering 113, no. 3 (September 1, 1991): 469–74. http://dx.doi.org/10.1115/1.2909519.
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Laser phase-doppler velocimetry measurements have been used to characterize the particle-gas sprays produced by straight-tube nozzles that simulate idealized fuel injectors for solid fuel combustion systems. Tests were conducted on two nozzle sizes, for two particle sizes, two loading ratios, and two gas velocities. The Reynolds numbers was varied from 9500 to 19000, and the Stokes number from 1.9 to 61.4. It was found that the velocities of the particles in the spray decelerate more slowly, and the velocity profiles are generally more narrow, than for a single-phase free-jet. The turbulence level of the particles in the sprays was found to be less than half the turbulence level of a single-phase free-jet, and the turbulent velocity profiles were not yet fully developed at X = 40D. The hydrodynamic characteristics of the nozzles that are the most important for combustion systems were found to be: (a) the particle spray expands radially at a cone angle of 2° (measured at the radius corresponding to the peak of the particle mass flux distribution); and (b) the nozzle pressure drop and particle mass flow can be related by a correlation that depends on loading ratio, Reynolds number, Stokes number, and the pressure drop coefficient of the nozzle for a single phase flow.
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Forster, M., and R. Steijl. "Design study of Coanda devices for transonic circulation control." Aeronautical Journal 121, no. 1243 (July 17, 2017): 1368–91. http://dx.doi.org/10.1017/aer.2017.65.
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ABSTRACTCirculation control via blowing over Coanda surfaces at transonic freestream Mach numbers is investigated using numerical simulations. The performance and sensitivity of several circulation control devices applied to a supercritical aerofoil are assessed. Different Coanda devices were studied to assess the effect of Coanda radius-to-slot height ratio, nozzle shape and Coanda surfaces with a step. The range of operating conditions for which a supersonic Coanda jet remained attached at transonic freestream conditions were extended by increasing the radius of curvature at the slot exit for Coanda devices with a converging nozzle. Additional improvements were found by reducing the strength of shock boundary-layer interactions on the Coanda surface by expanding the jet flow using a converging-diverging nozzle and also by introducing a step between the Coanda surface and the nozzle exit. The performance when using a converging-diverging nozzle can be matched using a simple stepped Coanda device. It is shown that circulation control has the potential to match the performance of traditional control surfaces during regimes of attached flow at transonic speeds, up to an equivalent aileron deflection angle of 10°. In addition, lift augmentation ratios ΔCl/Cμof over 100 were achieved.
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Lepikhin, S. A., and M. N. Galimzyanov. "High pressures and temperatures in the bubble liquid when it flows through the nozzle." Proceedings of the Mavlyutov Institute of Mechanics 4 (2006): 83–89. http://dx.doi.org/10.21662/uim2006.1.008.
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The stationary flow of a bubble gas-liquid mixture in a nozzle of circular cross-section is considered. The possibility of realizing superhigh temperatures and pressures in the gas phase at the nozzle site near the minimum cross section is analyzed. The effect of the parameters (the initial radius and the volume content of bubbles that determine the composition of the volume flow of liquid fed into the nozzle) on the flow pattern is studied.
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Methling, Ralf, Nicolas Götte, and Dirk Uhrlandt. "Ablation-Dominated Arcs in CO2 Atmosphere—Part II: Molecule Emission and Absorption." Energies 13, no. 18 (September 10, 2020): 4720. http://dx.doi.org/10.3390/en13184720.
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Molecule radiation can be used as a tool to study colder regions in switching arc plasmas like arc fringes in contact to walls and ranges around current zero (CZ). This is demonstrated in the present study for the first time for the case of ablation-dominated high-current arcs as key elements of self-blast circuit breakers. The arc in a model circuit breaker (MCB) in CO2 with and an arc in a long nozzle under ambient conditions with peak currents between 5 and 10 kA were studied by emission and absorption spectroscopy in the visible spectral range. The nozzle material was polytetrafluoroethylene (PTFE) in both cases. Imaging spectroscopy was carried out either with high-speed cameras or with intensified CCD cameras. A pulsed high-intensity Xe lamp was applied as a background radiator for the broad-band absorption spectroscopy. Emission of Swan bands from carbon dimers was observed at the edge of nozzles only or across the whole nozzle radius with highest intensity in the arc center, depending on current and nozzle geometry. Furthermore, absorption of C2 Swan bands and CuF bands were found with the arc plasma serving as background radiator. After CZ, only CuF was detected in absorption experiments.
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Nooranidoost, Mohammad, and Ranganathan Kumar. "Geometry Effects of Axisymmetric Flow-Focusing Microchannels for Single Cell Encapsulation." Materials 12, no. 17 (September 2, 2019): 2811. http://dx.doi.org/10.3390/ma12172811.
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Cell microencapsulation is a promising technique to protect living cells in biomedical applications. Microfluidic devices can be utilized to control the production of high-throughput cell-laden droplets. This paper demonstrates the effects of flow-focusing geometry on the droplet size, frequency of droplet generation, and number of cells per droplet. Orifice radius, orifice length, and nozzle-to-orifice distance can significantly influence the flow-field and manipulate droplet formation. This paper analyzes these geometry effects using a numerical front-tracking method for the three fluid phases. It is found that as the orifice radius increases, the drop size and the number of cells in the droplet increase. For a short orifice radius, increasing the orifice length results in the generation of smaller droplets at higher frequency and fewer cells per droplet. On the other hand, for a longer orifice, droplet production is invariant with respect to orifice length. It is also found that shorter distances between the nozzle and the orifice lead to a more controlled and uniform production of droplets. When the nozzle-to-orifice length is increased, the droplet formation becomes non-uniform and unpredictable. Probability charts are plotted with respect to the orifice length and orifice radius, which show that a greater than 50 % probability of single cell encapsulation can be achieved consistently.
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Hou, Rong Guo, Chuan Zhen Huang, Y. S. Feng, and Y. Y. Liu. "2D Simulation of the Gas-Solid Two Phase Flow inside the Abrasive Jet (AJ) Nozzle." Advanced Materials Research 53-54 (July 2008): 369–73. http://dx.doi.org/10.4028/www.scientific.net/amr.53-54.369.
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The simulation of the gas-solid two phase flow inside the abrasive jet nozzle is studied by the computed dynamic software (CFD)-FLUENT, the velocity field of the two phase flow and the trajectory of the abrasive inside the nozzle are obtained. The Eulerian multiphase model and the DPM model have been used to compute the two-phase flow field. The simulation results express that the velocity of the jet is slow at the inlet, while it will be increased with the area of the section decreasing, the cone angle of the nozzle affects the flow field very much, the flow has low turbulence and the gradient of the velocity is small when the cone angle is small, while the velocity of the flow increased rapidly and the gradient of the velocity is big when the cone angle increasing. The simulation results also express that the arc radius affects the flow field greatly, the flow will move more smoothly when the arc radius is large. The pressure field of the wall expresses that the nozzle will wear rapidly at the corner of the nozzle, the reason is that the pressure is big or changed greatly, the fatigue wear and the blast wear will happen at those place.
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He, Zhi Xia, Qing Mu Mu, Qian Wang, and Jian Ping Yuan. "Effect of Diesel Nozzle Geometry on Internal Cavitating Flow." Advanced Materials Research 97-101 (March 2010): 2925–28. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.2925.
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The presence of cavitation and turbulence in a diesel injector nozzle has significant effect on the subsequent spray characteristics. However, the mechanism of the cavitating flow and its effect on the subsequent spray is unclear. The initiation, development and collapse of the cavity are strongly influenced not only by the injection pressure and back pressure but also by the nozzle geometry. The numerical simulation of cavitating flow in nozzle holes of a vertical multi-hole injector with mixture multi-phase cavitating flow model was carried out. The effects of sac geometry, hole entrance curvature radius and hole inclination angle on the cavitating flow in nozzle holes were investigated. It is finally concluded that the performance of IMPROVED nozzle is better than that of STD nozzle and VCO nozzle and small inlet turning angle of the orifice can enhance the atomization of the spray.
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Pervez, T., SA Al-Hiddabi, A. Al-Yahmadi, and AC Seibi. "Dynamic Analysis and Vibration of Beam Inside Annulus for Ultra Short-Radius Water Jet Drilling." Journal of Engineering Research [TJER] 9, no. 1 (June 1, 2012): 55. http://dx.doi.org/10.24200/tjer.vol9iss1pp55-63.
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Conventional water-jet nozzle systems have been developed and partially used in the oil and gas industry to drill horizontal sidetracks. However, this technique still presents a few shortcomings associated with tube buckling and water jet sagging. Due to these problems, the drilled hole deviates from the desired path and does not reach the target reservoir. The issue becomes more complex due to the continuously moving boundaries representing the borehole profile, which is, in turn, governed by the nozzle dynamics. A mathematical model representing the dynamics of water jet drilling confined in a borehole along with drilling mud is developed to predict the sagging phenomenon during the drilling process. The closed form solution of the governing equation is obtained for horizontal drilling in shallow formation layers. The solution shows the strong influence of nozzle vibration and the magnitude of thrust force at the nozzle tip on the profile and the diameter of drilled hole. For sidetrack drilling of greater than 400 m length, the magnitude of sagging is large enough to miss the target reservoir. Furthermore, the dril string buckles at certain magnitudes of thrust forces and penetration lengths.
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Kocijel, Lino, Vedran Mrzljak, Maida Čohodar Husić, and Ahmet Čekić. "Numerical Analysis of Fuel Injector Nozzle Geometry - Influence on Liquid Fuel Contraction Coefficient and Reynolds Number." Journal of Maritime & Transportation Science 57, no. 1 (December 2019): 23–45. http://dx.doi.org/10.18048/2019.57.02.
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This paper investigates the influence of the fuel injector nozzle geometry on the liquid fuel contraction coefficient and Reynolds number. The main three fuel injector nozzle geometry parameters: nozzle diameter (d), nozzle length (l) and nozzle inlet radius (r) have a strong influence on the liquid fuel contraction coefficient and Reynolds number. The variation of the nozzle geometry variables at different liquid fuel pressures, temperatures and injection rates was analyzed. The liquid fuel contraction coefficient and Reynolds number increase with an increase in the nozzle diameter, regardless of the fuel injection rate. An increase in the r/d ratio causes an increase in the fuel contraction coefficient, but the increase is not significant after r/d = 0.1. A nozzle length increase causes a decrease in the fuel contraction coefficient. Increase in the nozzle length of 0.5 mm causes an approximately similar decrease in the contraction coefficient at any fuel pressure and any nozzle length. Fuel injectors should operate with minimal possible nozzle lengths in order to obtain higher fuel contraction coefficients.
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Chen, Rui, Hong Li, Jian Wang, and Chao Chen. "Effects of Plate Structure and Nozzle Diameter on Hydraulic Performance of Fixed Spray Plate Sprinklers at Low Working Pressures." Transactions of the ASABE 64, no. 1 (2021): 231–42. http://dx.doi.org/10.13031/trans.13958.
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HighlightsThe hydraulic performance of fixed spray plate sprinklers (FSPS) was evaluated at low working pressures.The effects of geometric structure on the hydraulic performance of FSPS were studied.A model was developed for estimating the application depth and uniformity of FSPS under a linear-move system.The recommended values of the most effective sprinkler combination spacing for FSPS are given.Abstract. Reducing the working pressure of sprinklers can effectively reduce the energy consumption of sprinkler irrigation systems. Fixed spray plate sprinklers (FSPS) have a simple structure, and their working pressure has potential to be reduced to 40 kPa. To evaluate the hydraulic performance of FSPS at low pressure, an experiment was conducted to investigate the effects of working pressure, plate structure, and nozzle diameter on sprinkler flow rate, wetted radius, and water application distribution. Two plates (FSPSB and FSPSY) and five nozzles were used in the tests. The cumulative water application depth and irrigation uniformity coefficient were calculated under a linear-move system. The results show that sprinklers with larger nozzle diameters and higher working pressures produce greater coefficients of discharge. The wetted radius gradually increases with the increase in working pressure and nozzle diameter. Two empirical equations for estimating the wetted radius of the two plates are proposed. The FSPSB has a concave trajectory structure that produces a longer wetted radius than the FSPSY, which has a flat trajectory structure. Along the wetted radius, the water application rate increases and then decreases, with a peak value at a certain distance. For the FSPSB, the peak rate of water application decreases with increasing working pressure. However, the FSPSY shows the opposite trend, with the maximum peak value occurring at the highest working pressure of 250 kPa. The water distribution for a single FSPSB sprinkler is discrete due to the greater water dispersal caused by the deeper grooves in the plate. In contrast, a single FSPSY sprinkler provides a more uniform water distribution. The irrigation uniformity of the FSPSY is higher than that of the FSPSB. The recommended values for the most effective sprinkler combination spacings for FSPSB and FSPSY are given in this article. The results may be useful for selecting appropriate sprinklers in hydraulic design procedures. Keywords: Cumulative spray water depth, Irrigation uniformity, Sprinkler irrigation, Water distribution, Working condition.
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Park, Sung Han, Jeong Whan Han, Chang Hee Lee, and Hyung Jun Kim. "Effect of Curvature on Gas-Particle Flow in Converging and Diverging Supersonic Nozzle." Solid State Phenomena 124-126 (June 2007): 1697–700. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.1697.
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A cold spray process is a relatively new process using high velocity metallic particles for surface modifications. Metallic powder particles which are injected into a converging-diverging nozzle are accelerated to supersonic velocities. In this study a comparative study was performed to figure out the effect of curvature on gas and particle flow in converging-diverging nozzle. And, the critical radius of curvature in converging and diverging section of nozzle and the behavior of the gas and particle flow were determined and calculated, respectively.
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Cai, H., B. Sun, B. Koplik, and J. Tavantzis. "Analytical Solutions of Openings Formed by Intersection of a Cylindrical Shell and an Oblique Nozzle Under Internal Pressure." Journal of Pressure Vessel Technology 121, no. 2 (May 1, 1999): 170–75. http://dx.doi.org/10.1115/1.2883681.
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This paper presents the analytical solutions of local circumferential and longitudinal stresses due to internal pressure on a cylindrical pressure vessel at the juncture of an opening formed by a nozzle with various intersecting angles in the case of thin wall vessels. First, we present the exact mathematical expression for the shell-nozzle intersection curve in mid-surface, and then solve the equations for the desired stresses using Fourier series methods. The resulting stresses are then normalized into stress concentration factors by means of the circumferential pressure stress. The influence of thickness is considered for stresses that have linear distribution along the thickness from inside to outside because of the thin wall vessel. For the ratio of nozzle radius/shell radius β = 0.4 and the ratio of shell radius/shell thickness γ = 40, the numerical calculations were performed for the stress concentration factors in both circumferential and longitudinal directions along the symmetric axes, and then plotted and tabulated for the intersection angles of 90, 75, 60, 45, and 30 deg, respectively. Numerical stress results indicate that the stresses for 30 deg intersection have the largest value. When the intersection angle is 90 deg, the results are in good agreement with the existing literature.
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Симашов, Р. Р., and С. В. Чехранов. "Determination of mass flow characteristics of supersonic axisymmetric nozzle diaphragms in modeling variable duties of low-consumption turbines." MORSKIE INTELLEKTUAL`NYE TEHNOLOGII), no. 4(50) (December 17, 2020): 39–43. http://dx.doi.org/10.37220/mit.2020.50.4.070.
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В работе приводятся обобщающие зависимости коэффициентов расхода сопловых аппаратов со сверхзвуковыми осесимметричными соплами в широком диапазоне изменения определяющих геометрических и режимных параметров. Предложена двухпараметрическая функция, учитывающая влияние расположения сопел в сопловом аппарате и степени конфузорности дозвуковой части осесимметричного сопла на коэффициент расхода. Показано слабое влияние на коэффициент расхода относительного радиуса закругления стенки в узкой части сопла и относительной длины дозвуковой части сопла в области их оптимальных значений определенных по минимуму потерь кинетической энергии. Переменные режимы работы сопла учитываются зависимостью относительного коэффициента расхода в функции от числа Рейнольдса в критическом сечении сопла. Полученные в работе эмпирические зависимости позволяют использовать их при моделировании переменных режимов и многорежимной оптимизации малорасходных турбин. The research presents generalizing dependences of mass flow rates in supersonic axisymmetric nozzle diaphragms n a wide range of variation of the governing geometric and operating parameters. A two-parameter function is proposed that takes into account the influence of the location of the nozzles in the nozzle apparatus and the degree of compression of the flow of the subsonic part of the nozzle on the mass flow rate. It is shown that the relative radius of rounding of the nozzle wall in the vicinity of the throat section and the relative length of the subsonic part of the nozzle in the region of their optimal values determined by the minimum of kinetic energy losses have a weak effect on the flow rate. Variable duties of nozzle operation are taken into account by the dependence of the relative flow rate as a function of the Reynolds number in the throat of the nozzle. The empirical dependencies obtained in this work make it possible to use them in modeling variable modes and multi-mode optimization of low-consumption turbines.
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Jasiūnienė, E., L. Mažeika, and O. Tumšys. "Investigation of ultrasonic inspection of the inner radius of a nozzle." Insight - Non-Destructive Testing and Condition Monitoring 55, no. 4 (April 1, 2013): 182–86. http://dx.doi.org/10.1784/insi.2012.55.4.182.
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Hayashi, Y., A. S. Pirozhkov, M. Kando, K. Ogura, H. Kotaki, H. Kiriyama, H. Okada, H. Gotoh, and T. Nishikawa. "Xe K-shell X-ray generation using conical nozzle and 25 TW laser." Laser and Particle Beams 31, no. 3 (June 26, 2013): 419–25. http://dx.doi.org/10.1017/s0263034613000190.
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AbstractTo increase X-ray photon number generated by laser-cluster interaction, it is important to understand the dependence of X-ray generation on cluster size. We carried out Xe K-shell X-ray generation using a conical nozzle with Xe clusters, the radius of which was controllable by adjusting the backing pressure. The experiment clarifies the result that the Xe K-shell X-ray photon number increases with increasing cluster radius from 8 to 12 nm, and saturates at the radius between 12 and 17 nm. We also investigated the Xe K-shell X-ray photon number dependence on laser intensity, and found that the threshold laser intensity of the Xe K-shell X-ray generation exists between 2 × 1017 and 5 × 1018 W/cm2.
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Duan, Yaoshuai, Zhiming Zhang, Binbin Lu, Boya Chen, and Zilong Lai. "The movement and forces of spinning solution in the nozzle during high-speed centrifugal spinning." Journal of Engineered Fibers and Fabrics 14 (January 2019): 155892501982820. http://dx.doi.org/10.1177/1558925019828207.
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High-speed centrifugal spinning is a novel method to fabricate nanofiber. It has the potential to fabricate nanofiber on a large scale because its production efficiency is much greater than traditional methods. Nozzle is an important part of high-speed centrifugal spinning equipment because its length, shape, and diameter all will affect the morphology and quality of nanofiber. It is useful to study the movement and forces of spinning solution in the nozzle. In this article, the principle and equipment structure of high-speed centrifugal spinning are briefly introduced at first. Then the movement and forces of spinning solution are analyzed by establishing parametric model at nozzle. It can be found that the spinning solution is ejected from nozzle when the rotating speed reaches a critical value. The critical rotating speed is inversely proportional to the radius of nozzle and directly proportional to the viscosity of spinning solution. There are several nozzle structures proposed and compared for nozzle optimization. Finally, the effects of nozzle parameters, concentration of spinning solution, and rotational speed on the morphology of nanofiber are verified by high-speed centrifugal spinning experiments. It lays the foundation for optimizing spinning equipment.
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Robinson, M., C. S. Lim, and R. Kitching. "Limit pressure for a spherical vessel with a circumferential slot at its junction with a radial cylindrical protruding branch." Journal of Strain Analysis for Engineering Design 22, no. 4 (October 1, 1987): 215–27. http://dx.doi.org/10.1243/03093247v224215.
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One of the requirements of the two criteria method of safety assessment of a pressure vessel with a defect is an estimate of the plastic limit pressure. Here the defect is in a spherical shell close to its junction with a protruding radial cylindrical branch. The defect is assumed to be an axisymmetric circumferential slot of uniform depth on the outer surface of the shell. Lower bounds to the limit pressure are calculated for a wide range of geometries. The material is assumed to obey the von Mises yield criterion and a non-linear programming method is used to give optimum lower bounds. Data is supplied for spherical shell radius to thickness ratios from 25 to 100, nozzle radius to vessel radius ratios from 0 to 0.4, nozzle to vessel thickness ratios from 0.25 to 1.0 and ligament thickness to vessel thicknesses (ligament efficiencies) of 0 to 1. Slot widths vary from the significant to the infinitesimal, where it becomes a crack. Vessels of some proportions were shown to have their limit pressures reduced only a little by very low ligament efficiencies.
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Liu, Bao Jun, Hai Xia Shi, and Yun Sheng Cai. "The Coupling Model of Wellbore Conduit Flow, Throttled Flow and Formation Seepage in Water Injection Wells." Advanced Materials Research 594-597 (November 2012): 2486–89. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.2486.
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Separate layer water flooding is adopted in most oilfields in China and the injection flow rate is controlled by the diameter of water nozzle of each layer. In order to ensure the effect of water injection, applicable water nozzles need to be adjusted to meet the requirements of injection flow rate. The adjustment is commonly realized according to experience, which leads to long adjustment time and low efficiency. To solve this problem, the coupling model of wellbore conduit flow, throttled flow and formation seepage was established based on theoretical analysis, which could provide theoretical basis for water nozzles adjustment. In the model, the Bernoulli Equation was adopted to analyze wellbore conduit flow; indoor experiments were done to research throttled flow; the research object of the seepage was finite radius well in homogeneous infinite formation.
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Chen, Alvin U., and Osman A. Basaran. "A new method for significantly reducing drop radius without reducing nozzle radius in drop-on-demand drop production." Physics of Fluids 14, no. 1 (January 2002): L1—L4. http://dx.doi.org/10.1063/1.1427441.
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Makaraci, Murat. "A Parametric Finite Element Geometric Analysis of a Pressurized Sphere with Cylindrical Flush Nozzle Outlet." Journal of Pressure Vessel Technology 127, no. 4 (June 1, 2005): 369–72. http://dx.doi.org/10.1115/1.2042472.
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A spherical, internally pressurized vessel with cylindrical flush nozzle outlet is analyzed in a parametric, linear displacement based finite element scheme. Geometric effects of outer convex radius design on the whole vessel body are investigated. An inside sharp corner where spherical section is joined with the flush nozzle outlet contributes to stress as well as degree of curvature in the outer convex radius. Stress and deformation states exhibit material, geometry, and internal pressure level dependencies. An important feature of the method, mesh convergence, is also validated for reliability of the results. Severe stress distributions and strain accumulations can be reduced through controlling outer geometric parameters. Materials having diverse mechanical properties such as carbon steel, Ti-Al-V alloy, near-eutectic Sn63-Pb37 solder alloy, and Nylon 66 are used for the vessel structure to reveal material dependence. Lower order elements are recommended for computational analysis.
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Jiang, Yue, Hong Li, Chao Chen, Lin Hua, and Daming Zhang. "Hydraulic Performance and Jet Breakup Characteristics of the Impact Sprinkler with Circular and Non-circular Nozzles." Applied Engineering in Agriculture 35, no. 6 (2019): 911–24. http://dx.doi.org/10.13031/aea.13268.
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HighlightsThe hydraulic performance of the impact sprinkler with circular and non-circular nozzles were measured.A High-Speed Photography (HSP) technique was employed to extract the jet breakup process of the impact sprinkler.Two index equations of jet characteristic lengths and equivalent diameters of non-circular nozzles were fitted. Abstract. An experiment was carried out to investigate the hydraulic performance of an impact sprinkler by using circular and non-circular nozzles. A High-Speed Photography (HSP) technique was employed to extract the breakup process and flow behavior of low-intermediate pressure water jets issued from the different types of orifices. These orifices were selected by the principle of equal flowrate with the same pressure. Moreover, two characteristic lengths: the jet breakup length and the initial amplitude of surface wave were measured. It was found that the sprinkler with circular nozzles produced the largest radius of throw followed by square nozzles and regular triangular nozzles when the cone angle of nozzle and pressure were unchanged, while the sprinkler with regular triangular nozzle had the best variation trend of water distribution and combination uniformity coefficient. Regular triangular jets exhibited a higher degree in breakup and the shortest breakup length compared with the square jets and the circular jets. The initial amplitudes of surface waves of regular triangular jets were larger than the square jets and the circular jets with the same cone angle. Two index equations of jet characteristic lengths and equivalent diameters of both circular and non-circular orifices were fitted with a relative error of less than 10%, which means the fitting formulas were accurate. Keywords: Breakup length, Fitting formula, Hydraulic performance, Initial amplitude, Non-circular jets.
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GAO, L., and S. C. M. YU. "A model for the pinch-off process of the leading vortex ring in a starting jet." Journal of Fluid Mechanics 656 (May 21, 2010): 205–22. http://dx.doi.org/10.1017/s0022112010001138.
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Modifications have been made to an analytical model proposed by Shusser & Gharib (J. Fluid Mech., vol. 416, 2000b, pp. 173–185) for the vortex ring formation and pinch-off process in a starting jet. Compared with previous models, the present investigation distinguishes the leading vortex ring from its trailing jet so as to consider the details of the pinch-off process in terms of the properties of the leading vortex ring, which are determined by considering the flux of kinetic energy, impulse and circulation from the trailing jet into the leading vortex ring by convective transportation. A two-stage process has been identified before the complete separation of the leading vortex ring from its trailing jet. The first stage involves the growth of the leading vortex ring by absorbing all the ejected fluid from the nozzle until certain optimum size is achieved. The second stage is characterized by the appreciable translational velocity of the leading vortex ring followed by a trailing jet. The leading vortex ring is approximated as a Norbury vortex ring with growing characteristic core radius ϵ such that dimensionless energy α, as well as its translational velocity and penetration depth, can be estimated. By applying the Kelvin–Benjamin variational principle, the pinch-off process is signified by two time scales, i.e. the formation number, which indicates the onset of the pinch-off process, and the separation time, which corresponds to the time when the leading vortex ring becomes physically separated from the trailing jet and is therefore referred to as the end of the pinch-off process. The effect of nozzle geometry, i.e. a straight nozzle or a converging nozzle, has also been taken into account by using different descriptions of the growth of the trailing jet. The prediction of the formation number and the characteristics of the vortex ring are found to be in good agreement with previous experimental results on starting jets with straight nozzles and converging nozzles, respectively.
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Tian, Xin Li, Ke Ling Lin, Bao Guo Zhang, and Chun Fang Xue. "Numerical Simulation of Temperature Field and Experimental Verification during Micro-Detonation of Arc Strike Machining." Advanced Materials Research 314-316 (August 2011): 661–66. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.661.
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A theoretical model of heat transfer for Si3N4 ceramics during micro-detonation of arc strike machining was established. Based on finite element theory, the temperature of Si3N4 ceramics during micro-detonation of arc strike machining was simulated with the aid of COMSOL Multiphysics software, combined with the actual processing, the width and depth of crater impacted by micro-detonation were calculated. The simulation results show that the highest temperature of Si3N4 ceramics is over 12100 °C in a given processing parameters, while the high-temperature zone is quite small; the material removal rate with the increase of pulse width and electricity increases, with the increase of the nozzle radius first increases and then decreases; the diameter to depth ratio with the increase of pulse width and electricity decreases, with the increase of nozzle radius increases. The data gained from the simulation is proved to be accordant with the data gained from experiments.
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Michalek, K., K. Gryc, M. Tkadlečková, J. Morávka, T. Huczala, D. Bocek, and D. Horáková. "Influence of Submerged Entry Nozzle on Intermixed Zone in Round Blooms with a Diameter of 525 mm / Wpływ Wylewu Zanurzeniowego Na Strefe Przejsciowa W Okragłych Wlewkach Ciagłych O Srednicy 525 mm." Archives of Metallurgy and Materials 58, no. 1 (March 1, 2013): 187–91. http://dx.doi.org/10.2478/v10172-012-0171-8.
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This work compares the experimental results of nickel concentration measurements in the intermixed zone of the continuously cast round blooms with a diameter of 525 mm using two types of submerged entry nozzles (SEN) - a straight-through nozzle and one with 5-ports. Based on determination of the system and optical interface in the blooms a detailed study of concentration profiles on the bloom surface in a small radius area, on the right side and then also on a cross-section of the blooms, was carried out. The results were further analysed using approximation models, and were to be used to verify the proposed model for predicting intermixed zones for a continuous casting machine, developed based on the results of physical and numerical modelling.
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Whipple, R. A. "Experimental Investigation of Nozzle-Induced Cylindrical Shell Stresses Where R/T = 1264." Journal of Pressure Vessel Technology 108, no. 1 (February 1, 1986): 98–107. http://dx.doi.org/10.1115/1.3264758.
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Stresses and displacements for a nozzle connection typical of those found in large storage tanks or pressure vessels were measured for applied radial forces, circumferential moments and longitudinal moments. The test program was conducted on a 12 1/2-in-dia penetration, centered and welded into a 60 in. × 60 in. cylindrical panel with a radius to thickness ratio of 1264. The nozzle diameter to cylindrical shell diameter ratio was 0.05. The panel edges were bolted to a stiff rectangular frame. This report presents the measured radial deflections and nozzle rotations, the membrane stress resultants and shell bending moments in the vicinity of the penetration along with penetration membrane and bending stresses for the three loadings. A brief description of the model and the test procedure is also presented.
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Xie, Zheng Wen. "Numerical Simulation and Experimental Study on Water Mist Fire Suppression for Cooking Fog Discharge Pipe." Advanced Materials Research 915-916 (April 2014): 356–61. http://dx.doi.org/10.4028/www.scientific.net/amr.915-916.356.
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FDS simulation software was used to establish the full size lampblack physics model of single wind pipe, using the orthogonal design method design of analog calculation conditions, research in the nozzle pressure, the droplet radius, nozzle, flow quantity and injection angle parameters under different conditions of water mist fire extinguishing effect. Based on a full-scale combustion and water mist fire extinguishing experiment, the water mist fire suppression was observed and test analysis etc, to better understand the flue water mist fire extinguishing feasibility, provides the theory basis for the design of efficient, reliable flue fire extinguishing system.
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Yu, Guo Qiang, Fei Wang, and Guang Du. "Finite Element Analysis of Stamped Tees Stress in Directly Buried Heating Pipeline." Applied Mechanics and Materials 405-408 (September 2013): 997–1001. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.997.
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In order to provide evidence for optimization design of directly buried heating pipeline tees, finite element models of tees with different ratios of branch-main pipe diameters had been established and simulated by structure analysis soft ANSYS. The change law of maximum equivalent stress values in pipe-nozzle intersection area had been obtained at same temperature, pressure loads and displacement constraints. The results show that maximum equivalent stress values of stamped tees are less than welded tees with same specifications. And stamped tees with lager fillet radius and local wall thickness can effectively decrease maximum equivalent stress values of pipe-nozzle intersection area.
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Yang, Yang, Shoudong Gu, Jianfang Liu, Hongyu Tian, and Qingqing Lv. "Research and Development of a 3D Jet Printer for High-Viscosity Molten Liquids." Micromachines 9, no. 11 (October 28, 2018): 554. http://dx.doi.org/10.3390/mi9110554.
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Micro-droplet jetting manufacture is a new 3D printing technology developed in recent years. Presently, this new technology mainly aims at ejecting a low-viscosity medium. Therefore, a device for ejecting high-viscosity molten liquid is designed by analyzing the injection principle of high-viscosity molten liquid. Initially, the cooling mechanism is designed to overcome the defect that the piezoelectric stacks cannot operate in high-temperature conditions. Thereafter, the mathematical model of the liquid velocity in the nozzle is derived, and the factors influencing injection are verified by Fluent. Subsequently, a prototype of the jet printer is fabricated, and the needle velocity is tested by the laser micrometer; the relationship between voltage difference and the needle velocity is also obtained. The experimental results matched the theoretical model well, showing that the voltage difference, needle radius, nozzle diameter, and taper angle are closely related to the injection performance of the 3D jet printer. By using a needle with a radius of 0.4 mm, a nozzle with a diameter of 50 μm, a taper angle of 90°, a supply pressure of 0.05 Mpa, and a voltage difference of 98 V, a molten liquid with a viscosity of 8000 cps can be ejected with a minimum average diameter of 275 μm, and the variation of the droplet diameter is within ±3.8%.
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Delale, Can F., Kohei Okita, and Yoichiro Matsumoto. "Steady-State Cavitating Nozzle Flows With Nucleation." Journal of Fluids Engineering 127, no. 4 (April 2, 2005): 770–77. http://dx.doi.org/10.1115/1.1949643.
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Quasi-one-dimensional steady-state cavitating nozzle flows with homogeneous bubble nucleation and nonlinear bubble dynamics are considered using a continuum bubbly liquid flow model. The onset of cavitation is modeled using an improved version of the classical theory of homogeneous nucleation, and the nonlinear dynamics of cavitating bubbles is described by the classical Rayleigh-Plesset equation. Using a polytropic law for the partial gas pressure within the bubble and accounting for the classical damping mechanisms, in a crude manner, by an effective viscosity, stable steady-state solutions with stationary shock waves as well as unstable flashing flow solutions were obtained, similar to the homogeneous bubbly flow solutions given by Wang and Brennen [J. Fluids Eng., 120, 166–170, 1998] and by Delale, Schnerr, and Sauer [J. Fluid Mech., 427, 167–204, 2001]. In particular, reductions in the maximum bubble radius and bubble collapse periods are observed for stable nucleating nozzle flows as compared to the nonnucleating stable solution of Wang and Brennen under similar conditions.
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Schulkes, R. M. S. M. "The evolution and bifurcation of a pendant drop." Journal of Fluid Mechanics 278 (November 10, 1994): 83–100. http://dx.doi.org/10.1017/s0022112094003629.
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In this paper we calculate how a pendant drop evolves at the end of a nozzle when the volume of the drop increases steadily with time. We find that the character of the evolution is strongly dependent on the growth rate of the drop and the radius of the nozzle. Typically we find that once the drop has become unstable, two bifurcations occur shortly after each other when the growth rate of the drop is slow. For large growth rates the bifurcations are well-separated in time. We are able to calculate the volumes of the drops after the bifurcations. A comparison with experimental data shows a satisfactory agreement.
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Ibrahim, E. A., and T. R. McKinney. "Injection characteristics of non-swirling and swirling annular liquid sheets." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 220, no. 2 (February 1, 2006): 203–14. http://dx.doi.org/10.1243/09544062c02505.
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A simplified mathematical model, based on body-fitted coordinates, is formulated to study the evolution of non-swirling and swirling liquid sheets emanated from an annular nozzle in a quiescent surrounding medium. The model provides predictions of sheet trajectory, thickness, and velocity at various liquid mass flowrates and liquid-swirler angles. It is found that a non-swirling annular sheet converges towards its centreline and assumes a bell shape as it moves downstream from the nozzle. The bell radius and length are more pronounced at higher liquid mass flowrates. Both the thickness and the stream-wise velocity of the non-swirling annular sheet are reduced with an increase in mass flowrate. The introduction of swirl results in the formation of a diverging hollow-cone sheet. The hollow-cone divergence from its centreline is enhanced by an increase in liquid mass flowrate or liquid-swirler angle. The hollow-cone sheet radius, curvature, and stream-wise velocity increase, whereas its thickness is diminished as a result of increasing the mass flowrate or liquid-swirler angle. The tangential velocity is greater at higher mass flowrates or smaller liquid-swirler angles. The present results are compared with previous studies and conclusions are drawn.
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Lkhagvasuren, Delgermaa, Nuuts Yadamsuren, Otgonkhuyag Balgan, and Byambadorj Chagnaa. "result of the influence of center pivot irrigation machine operations on rain (irrigation) intensity." Mongolian Journal of Agricultural Sciences 32, no. 1 (June 23, 2021): 94–98. http://dx.doi.org/10.5564/mjas.v32i1.1611.
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The water consumption through the nozzle or water pressure through the nozzle at the given water thickness (У,min) the two technological parameters, the pressure of the nozzle (X1, PSI) and the rotational speed of the nozzle (X2, m/min) are used to determine the state of the impact at 8 mm nozzle. The experiment was determined under laboratory conditions on a Low Energy Nozzle (LEN). The experiment was conducted in the ‘’ Irrigation machinery and equipment design’’ laboratory of the School of Engineering and Technology of the MULS using the ‘’Low pressure nozzle distribution radius and rain intensity measuring equipment’’. The maximum intensity of water supplied by the nozzle is 1.727 mm / min or the maximum pressure is 30 PSI and the minimum flow rate is 0.313 mm / min. The pressure regulator at 20 min was at a value of 20 PSI, and the transition speed was at a maximum of 3 m / min.
Бороожуулах эрчимд машины ажиллах горим нөлөөлөх байдлыг тодорхойлсон дүн
Бороожуулах хошуугаар өгч байгаа усны зарцуулгын хэмжээ буюу өгсөн усны зузаанд (Y, мм) хошуугаар гарах усны даралт , машины тойрох хурд гэсэн технологийн хоёр параметр дангаараа болон хавсран үзүүлэх нөлөөллийн төлвийг тодорхойлох туршилтыг 8 мм голчтой бороожуулах хошуун дээр лабораторийн нөхцөлд тодорхойлов. ХААИС-ийн ИТС-ийн “ Усалгааны машин, тоног төхөөрөмжийн хийц “лабораторт 2019 онд “Бороожуулах хошууны борооны эрчим, усны жигд тархалт тодорхойлох төхөөрөмж”- ийг ашиглан туршилтыг хийж гүйцэтгэв. Нам даралтат бороожуулах хошууны борооны эрчмийг тодорхойлж, үр дүнг математик статистикийн аргаар боловсруулахад бороожуулах хошуугаар өгч буй усны хамгийн их хэмжээ 1.727 мм/мин нь даралт хамгийн их 30 PSI, шилжих хурд хамгийн бага 1м/мин үед байгаа бол хамгийн бага хэмжээ 0.313 мм/мин нь даралт тохируулагч 20 PSI утга дээр, шилжих хурд хамгийн их буюу 3 м/мин байв.
Түлхүүр үг: Даралт тохируулагч, бороожуулах хошууны жигд тархалт, нам даралтат бороожуулах хошуу