Academic literature on the topic 'Dual-inlet system'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Dual-inlet system.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Dual-inlet system"
1
Velasquez-Montoya, Liliana, Elizabeth J. Sciaudone, and Margery F. Overton. "RESPONSE OF OREGON INLET TO PEA ISLAND BREACHING." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 82. http://dx.doi.org/10.9753/icce.v36.papers.82.
Full textAbstract:
This study aims to assess the effects of a new inlet on the hydrodynamics of a semi-permanent tidal inlet and the back-barrier sound. Research on dual-inlet interactions is motivated by the increased vulnerability of barrier islands to breaching during hurricanes, phenomenon that can have important consequences on the hydrodynamics and morphology of a barrier island system with pre-existing inlets. This particular study takes place in the northern Outer Banks of North Carolina, where Oregon Inlet is the main inlet connecting the Atlantic Ocean with the Albemarle-Pamlico Sound. During Hurricane Irene in 2011, Pea Island – the island south of Oregon Inlet – was breached creating a new inlet that remained open until 2013. Dual-inlet interactions between Oregon Inlet and the new inlet in Pea Island are analyzed by means of numerical modeling experiments. Changes in flow velocities, water levels, and the tidal prism of Oregon Inlet due to the new inlet are computed for different wave and water level conditions. In addition to the actual inlet that opened in 2011, the effects of idealized inlets with different geometries and location are also included in this study. Results indicate that the original breach in Pea Island did not modify the dynamics of Oregon Inlet. Instead, its effects were restricted to a 5 km radius that extended mostly into the sound. The relative small size of the breach and its distance from Oregon Inlet are the two main factors that prevented dual-inlet interaction. Exploration of idealized breaching scenarios in Pea Island suggests that inlet spacing and breaching geometry play a major role in multiple inlet stability theory.
2
Knight, J. D., A. M. Matus, C. van Kessel, G. R. Parry та A. E. Slinkard. "Comparison of a dual‐inlet gas isotope ratio mass spectrometry system and an automated single‐inlet mass spectrometry system for δ13C analysis". Communications in Soil Science and Plant Analysis 25, № 3-4 (1994): 447–54. http://dx.doi.org/10.1080/00103629409369050.
Full text
3
Wang, Shiqi, and Zhongyuan Yuan. "A Hot Water Split-Flow Dual-Pressure Strategy to Improve System Performance for Organic Rankine Cycle." Energies 13, no. 13 (2020): 3345. http://dx.doi.org/10.3390/en13133345.
Full textAbstract:
The organic Rankine cycle (ORC) is widely used to recover industrial waste heat. For an ORC system using industrial waste hot water as a heat source, a novel hot water split-flow dual-pressure organic Rankine cycle (SFD-ORC) system is developed to improve the performance of the ORC. The maximum net power output was selected to compare three ORC systems, including basic ORC (B-ORC), conventional dual-pressure ORC (CD-ORC) and SFD-ORC. A genetic algorithm (GA) was used to optimize the parameters to search the maximum net power output of ORCs. The maximum net output power was taken as the standard of performance evaluation. The results show that, under the same hot water inlet temperature condition, the optimal hot water outlet temperature of B-ORC is much higher than that of CD-ORC and SFD-ORC, which indicates that less thermal energy could be utilized to convert to power in B-ORC. The optimal hot water temperature at the outlet of evaporator 1 in SFD-ORC is higher than that in CD-ORC, which means SFD-ORC could make more efficient use of the high-grade thermal energy of hot water. The SFD-ORC could obtain the highest net output power under the optimal parameter conditions, followed by the CD-ORC system, while the B-ORC has the lowest net output power. Moreover, with the increase in the hot water inlet temperature, the advantage of SFD-ORC becomes increasingly obvious. When the hot water inlet temperature is 90 °C, the net output power of SFD-ORC at is 6.22% higher than that of CD-ORC. The net output power of SFD-ORC at 130 °C increases to 9.7% higher than that of CD-ORC. The SFD-ORC presents better system performance and has great engineering application potential.
4
Yang, Kai-Shing, Kun-Huang Yu, Ing-Youn Chen, and Chi-Chuan Wang. "Influence of Inlet Configurations on the Refrigerant Distribution of a Dual Cold-Plate System." Heat Transfer Engineering 31, no. 8 (2010): 692–98. http://dx.doi.org/10.1080/01457630903466688.
Full text
5
Guan, Xiao Le, and Wei Gang Zheng. "Analysis of Combustion and Emission Characteristics of Diesel, Natural Gas Dual Fuel Engine." Advanced Materials Research 744 (August 2013): 248–52. http://dx.doi.org/10.4028/www.scientific.net/amr.744.248.
Full textAbstract:
Research on combustion characteristics of diesel, natural gas dual fuel engine, and to analyze the influence of pilot diesel fuel supply system parameters on the combustion characteristics of dual fuel engine. Based on the experiment, firstly comparing the combustion characteristics of diesel engine with diesel, natural gas dual fuel engine, and compared the effect of load on the combustion characteristics of dual fuel engines, and specifically elaborated the load, speed, rate of substitution, effects of ignition oil quantity, inlet concentration of the mixed gas, the fuel supply advance angle and other factors on combustion changes of dual fuel heat release rate, pressure, discharge characteristics.Analysis of the natural gas / diesel dual fuel engine is currently studying the existing problems of key technologies and development prospects.
6
Abdel-Fattah, A. M. "Education Committee Best Paper of 1996 Award: Response of a Turbofan Engine Compression System to Disturbed Inlet Conditions." Journal of Turbomachinery 119, no. 4 (1997): 677–85. http://dx.doi.org/10.1115/1.2841177.
Full textAbstract:
A generic code DYNTECC has been adapted to perform a parametric study of the effect of inlet flow distortion on the stability of the Pratt and Whitney TF30 engine. This code was developed at Arnold Engineering Development Center, USA, for single and dual spool systems. It was modified at AMRL to accommodate the particular geometry of the TF30 engine. The stage characteristics needed to operate DYNTECC were derived from experimental data for the fan and low-pressure compressor. For the high-pressure compressor they were derived using the STGSTK code developed at NASA Lewis Research Center. This program was modified at AMRL to include real flow effects that were in turn derived using yet another adapted code, CASCAD. The code was primarily used at AMRL to predict the onset of system instability due to simulated full-face rapid inlet temperature ramps typical of those caused during armament firings. It was also run with sinusoidal total pressure oscillations of varying amplitudes and frequencies at the inlet. The code predictions were compared with available data whenever possible, and were found to be consistent with the observed experimental trends.
7
Osterwalder, S., J. Fritsche, C. Alewell, et al. "A dual-inlet, single detector relaxed eddy accumulation system for long-term measurement of mercury flux." Atmospheric Measurement Techniques 9, no. 2 (2016): 509–24. http://dx.doi.org/10.5194/amt-9-509-2016.
Full textAbstract:
Abstract. The fate of anthropogenic emissions of mercury (Hg) to the atmosphere is influenced by the exchange of elemental Hg with the earth surface. This exchange holds the key to a better understanding of Hg cycling from local to global scales, which has been difficult to quantify. To advance research about land–atmosphere Hg interactions, we developed a dual-inlet, single detector relaxed eddy accumulation (REA) system. REA is an established technique for measuring turbulent fluxes of trace gases and aerosol particles in the atmospheric surface layer. Accurate determination of gaseous elemental mercury (GEM) fluxes has proven difficult due to technical challenges presented by extremely small concentration differences (typically < 0.5 ng m−3) between updrafts and downdrafts. We present an advanced REA design that uses two inlets and two pairs of gold cartridges for continuous monitoring of GEM fluxes. This setup reduces the major uncertainty created by the sequential sampling in many previous designs. Additionally, the instrument is equipped with a GEM reference gas generator that monitors drift and recovery rates. These innovations facilitate continuous, autonomous measurement of GEM flux. To demonstrate the system performance, we present results from field campaigns in two contrasting environments: an urban setting with a heterogeneous fetch and a boreal peatland during snowmelt. The observed average emission rates were 15 and 3 ng m−2 h−1, respectively. We believe that this dual-inlet, single detector approach is a significant improvement of the REA system for ultra-trace gases and can help to advance our understanding of long-term land–atmosphere GEM exchange.
8
Sun, Xian Peng, Zhi Rong Zou, and Yue Zhang. "The Combined Solar with a Dual Heat Source Heat Pump Applied in a Greenhouse Heating System - An Operation Optimization of Water Source Heat Pump." Applied Mechanics and Materials 541-542 (March 2014): 942–48. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.942.
Full textAbstract:
Based on the finite-time thermodynamic theory, an operation optimization, of water source heat pump in the combined solar with a dual heat source heat pump which is applied in a greenhouse heating system, is made. According to the ε-NTU method and entropy theory, heat exchange and balance equations are obtained. The function relationship between COP and the indoor temperature Tn, the ambient temperature Ta, low temperature heat source inlet temperature Tie and high temperature heat source inlet temperature Tic is also obtained. By means of programming, the impact of parameters on the COP and the way of regulating this water source heat pump system are presented in this article. The results show that: when a separate water source heat pump is running, by adjusting the hot water temperature and the match status of each indoor heating system, the energy-saving operation can be realized.
9
De Armas Calderón, Nelly, Cristina Lizarazo Bohórquez, and Jorge Duarte Forero. "Exergetic analysis of a dual-fuel engine, PEM electrolyzer and thermoelectric generator integrated system." DYNA 87, no. 215 (2020): 66–75. http://dx.doi.org/10.15446/dyna.v87n215.84305.
Full textAbstract:
In this research, the implementation of an integrated system composed of a dual-fuel engine (Diesel-Hydrogen), a PEM electrolyzer and a thermoelectric generator is envisioned. In order to know the optimal operating conditions of each sub-system, the exergetic efficiency and destroyed exergy were studied. It was estimated that for the dual combustion engine, the destroyed exergy would increase as a function of the concentration of methane in its mixture. By varying the electrical input to the electrolyzer, it was found that when the input current was 2A, the exergetic efficiency would go up to 92.59%, while for a current of 5A, the efficiency decreased in 51.80%. Finally, the exergetic efficiency of TEG decreased by increasing the hot flow temperature; 86.68% of the decrease in efficiency occurred for temperatures between 470K and 510K. On the other hand, the destroyed exergy increased linearly with an increase in the inlet temperature of exhaust gases.
10
Wang, Ping, and Tanya M. Beck. "Morphodynamics of an anthropogenically altered dual-inlet system: John's Pass and Blind Pass, west-central Florida, USA." Marine Geology 291-294 (January 2012): 162–75. http://dx.doi.org/10.1016/j.margeo.2011.06.001.
Full textDissertations / Theses on the topic "Dual-inlet system"
1
Xie, Ming. "Verification and Comparison of Two Commonly Used Numerical Modeling Systems in Hydrodynamic Simulation at a Dual-Inlet System, West-Central Florida." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5442.
Full textAbstract:
Numerical modeling systems are very important tools to study tidal inlets. In order to test its capability and accuracy of solving multi-inlet system problems, this study selected two widely used numerical modeling systems: Coastal Modeling System (CMS) and Delft3D Modeling Package. The hydrodynamics modules of the two modeling systems were tested at John's Pass and Blind Pass, Florida, a dual-inlets system, based on a similar modeling scheme. Detailed bathymetric surveys and hydraulic measurements were conducted to collect water depths, tide conditions, wave and current velocities as the input data as well as verification data for the models.
A comparison study was conducted by comparing computed hydrodynamic results from both models with the extensive field measurement data. Results show that both of the modeling systems yield better prediction for water levels than for current velocity. Furthermore, under the similar modeling scheme, Delft3D was able to capture the measured tidal phase lag between the ocean boundary and the coastal inlet, therefore gave better water level prediction than the CMS model. However, the CMS yielded current velocities that are closer to the measured values than the DELFT3D model. CMS has a more user-friendly Graphic User's Interface (GUI) for input data preprocessing and plotting and visualization of output data. Delft3D has faster calculation speed.
2
Horwitz, Mark H. "Morphodynamics and Sediment Pathways of the John's Pass-Blind Pass Dual-Inlet System: Pinellas County, Florida." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6864.
Full textAbstract:
The morphodynamics of an inlet channel draining an estuary or bay are governed by a complex system of temporally and spatially varying physical processes, including wind, waves, tides, sediment transport, and both tide and wave driven currents. In addition, sediment availability and characteristics in conjunction with underlying geologic framework bear on the morphology and morphologic behavior of an inlet system. This study examines the morphodynamics, sediment transport patterns and time-series morphologic change of John’s Pass and Blind Pass, two structured tidal inlets that collectively make up a dual-inlet system sharing the tidal prism of northern Boca Ciega Bay, in Pinellas County, Florida.
To quantify wave and tidal forcing and response mechanisms an array of hydrodynamic sensors were deployed over a 12 month period at both inshore and offshore locations. In order to capture morphologic changes and quantify volumetric changes within the inlets, bathymetric surveys of the inlets were conducted in 2010, 2011, 2012, and 2014. Similarly, bi-monthly beach survey data for the same range of time was acquired in order to quantify volumetric changes along adjacent stretches of beach. In addition to gaining insights into sediment pathways based on morphologic and volumetric variability, those data were also used to develop a regional sediment budget along the studied stretch of coast.
To gain insights into the morphodynamics of the dual-inlet system, bathymetric and hydrodynamic data was used to develop a numerical model of the dual inlet system. Numerical model simulations based on existing or baseline conditions were compared with numerical simulations employing synthetic bathymetric and hydrodynamic conditions in order to examine inlet behavior under a range of different morphological and hydrodynamic conditions.
John’s Pass is the dominant of the two inlets. It exhibits mixed-energy straight morphology and captures ca 81% of the available tidal prism. The inlet has a well-developed mature ebb shoal, and actively bypasses sediment from one side of the inlet to the other supplying sediment to the downdrift littoral system. Blind Pass captures less than 20% of the available tidal prism, and while also exhibiting mixed-energy morphologic characteristics has a less well developed ebb shoal that currently has not fully established a sediment bypassing system.
Both inlets channels and ebb shoals have been dredged on multiple occasions to provide sediment for the nourishment of nearby chronically eroding stretches of beach. Dredge pits excavated along the distal margins of the ebb shoals are infilling at rates substantially slower than expected due to limited sediment transport along those regions of the ebb shoal, while inlet channel dredge pits infill at rapid and expected rates. The objective of this study was to characterize the morphodynamics of the dual-inlet system with the aim of identifying sediment pathways and bypassing mechanisms, and quantify a balanced regional sediment budget in order to design more sustainable approaches to inlet management.
Conference papers on the topic "Dual-inlet system"
1
WANG, PING, JUN CHENG, MARK H. HORWITZ, and KELLY R. LEGAULT. "COMPARING TWO NUMERICAL MODELS IN SIMULATING HYDRODYNAMICS AND SEDIMENT TRANSPORT AT A DUAL INLET SYSTEM, WEST-CENTRAL FLORIDA." In Coastal Sediments 2015. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814689977_0135.
Full text
2
Bhuiya, Md Mainul Hossain, Chi Young Lee, Ryan Hopkins, et al. "A High-Performance Dual-Stage Hydrogen Compressor System Using Ca0.2Mm0.8Ni5 Metal Hydride." In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5120.
Full textAbstract:
Dual stage hydrogen compressor with high pressure compression ability can operate efficiently using geothermal, low temperature solar, waste energy as well as combination of these energy sources. In this study, a dual stage thermal compressor system for hydrogen compression was investigated using three different hydrogen storage materials: LaNi5, Ca0.6Mm0.4Ni5 and Ca0.2Mm0.8Ni5. Compression ratio of Ca0.2Mm0.8Ni5 was found to be 56% and 14.7% higher than those of LaNi5 and Ca0.6Mm0.4Ni5 respectively, for single stage thermal compressor system with inlet supply pressure of 600 psig. On the other hand, compression performance of Ca0.2Mm0.8Ni5 was similar to that of LaNi5 at low supply pressure (e.g. 200 psig) condition. In this paper, a dual stage hydrogen compressor system with LaNi5 in first stage and Ca0.2Mm0.8Ni5 in second stage is proposed for high pressure hydrogen compression based on the experimental results of single stage system. Results show that 53% higher compression ratio can be attained using dual stage hydrogen compressor when appropriate storage materials are selected for two stages.
3
Abdel-Fattah, Adnan M. "Response of a Turbofan Engine Compression System to Disturbed Inlet Conditions." In ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/96-gt-206.
Full textAbstract:
A generic code DYNTECC has been adapted to perform a parametric study of the effect of inlet flow distortion on the stability of the Pratt and Whitney TF30 engine. This code was developed at Arnold Engineering Development Center, USA, for single and dual spool systems. It was modified at AMRL to accommodate the particular geometry of the TF30 engine. The stage characteristics needed to operate DYNTECC were derived from experimental data for the fan and low pressure compressor. For the high pressure compressor they were derived using the STGSTK code developed at NASA Lewis Research Center. This program was modified at AMRL to include real flow effects that were in turn derived using yet another adapted code CASCAD. The code was primarily used at AMRL to predict the onset of system instability due to simulated full-face rapid inlet temperature ramps typical of those caused during armament firings. It was also run with sinusoidal total pressure oscillations of varying amplitudes and frequencies at the inlet. The code predictions were compared with available data whenever possible, and were found to be consistent with the observed experimental trends.
4
Zamzam, Montaser M., and Abdalla M. Al-Amiri. "A Novel Free-Cooling Scheme for Combustion Turbine Inlet Air Cooling." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27621.
Full textAbstract:
Free-cooling is a well-known concept in the HVAC industry in which the cold water produced by cooling tower is used directly to satisfy the requirement of the cooling load without assistance by the chiller, this concept, however, is not reported in the turbine inlet air cooling applications. Free-cooling works well as long as the ambient wet bulb temperature WBT is sufficiently low to produce cold water at the required temperature but once WBT reaches its threshold value hence free-cooling mode is ceased and the chiller kicks off working under its normal mode of operation i.e. free-cooling is either enabled or disabled. The proposed system in this paper provides in addition to the above modes of operation a novel mode that utilizes the cooling tower as primary source of cooling simultaneously with the chiller which serves as a secondary source at elevated WBT. This new feature significantly reduces the yearly operating hours of the chiller and possibly its size depending on the desired inlet air temperature, actual weather conditions and design WBT. Chiller size can vary between 0-100 percent as compared to a similar classical chiller system with significant reduction in the operating hours. The proposed system basically consists of chiller, cooling tower, cooling coils, interconnecting piping and controls. The arrangement of the system equipments changes with the operation modes in two configurations; dual water circulation loops and single water circulation loop. In the dual loops configurations the system has two separate loops such that the evaporator and the cooling coils are tied in one loop while the cooling tower and condenser in the other loop whereas in the single loop configuration all equipments are connected in series in one water circulation loop. This paper presents the major equipments and characteristics of the novel chiller scheme. In addition, the study outlines the potential reduction in the chiller load, size and operating hours under a generalized weather envelope. The paper in general portrays the feasibility of using the proposed cooling scheme for turbine inlet air cooling.
5
Förster, Siegfried, and Peter Quell. "A Low NOx Combustion System and a Ceramic Cross Flow Heat Exchanger for Small Gas Turbines." In ASME 1987 International Gas Turbine Conference and Exhibition. American Society of Mechanical Engineers, 1987. http://dx.doi.org/10.1115/87-gt-109.
Full textAbstract:
A new low NOx oil-combustion system with superheated steam fuel evaporation prior to combustion has been found especially feasible for open cycle gas turbines with high turbine inlet temperatures and ceramic cross flow heat exchanger. The actual state of development of both the low NOx light fuel-oil combustion system and ceramic heat exchanger elements, especially the cross flow type, is outlined in this paper. The use of this combustion system results in considerably lower combustion temperatures in the primary combustion zone, reducing the NOx-production even at high air temperatures when the air is preheated in the heat exchanger. The water vapour used for the evaporation of the fuel oil before combustion has an improving effect on the cycle efficiency comparable to the Cheng-dual-fluid-cycle. Illustrative evaluations for a gas turbine cycle for a shaft power of 70 kW are given.
6
Wang, Chengyang, Qudus Hamid, Jessica Snyder, Halim Ayan, and Wei Sun. "A Novel Automation System for Microplasma Surface Patterning and Biologics Printing." In ASME/ISCIE 2012 International Symposium on Flexible Automation. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/isfa2012-7106.
Full textAbstract:
In the field of tissue engineering, regenerative medicine, and life sciences, the topological biochemical cues regulate cell attachment and alignment within the construct. In a native biological system, these cues are inherent. However, most of the biological materials utilized in the fabrication of tissue construct do not possess the appropriate cues required to develop an architecture to support the cell attachment and growth of a functional tissue Therefore the ability to manipulate structural and biochemical cues plays an important role in biofabrication process, and it is a key element to evaluate a engineered cellular model. Plasma surface functionalization and biologics printing have been investigated and validated as two effective techniques to guide cell functions by creating microenvironments. The objective of this work is to develop a novel dual functional platform for freeform microplasma surface patterning and biologics printing process as well as to study the underlying process science and the process induced cellular functions. The microplasma jet system was assembled by two parts. The upper part is a plastic NPT connector surrounding an extending high voltage copper electrode. The lower part is a dielectric Pasteur pipette connected with a capillary micro-scale nozzle tip. The lower part is interchangeable and the diameter of the tip ranges from 50 μm to 1 mm. With up to 20 kV output capability, a high-voltage power supply was connected to the copper electrode through the NPT connector which also served as gas inlet. A high-voltage probe linked to an oscilloscope is used to monitor the real time voltage. The whole microplasma jet system was set up on automation platform, which allows X-Y-Z motion control and switch control. This integrated system operates at atmospheric pressured environment. All tissue constructs could be fabricated at room temperature without the use of a mask. Clear polystyrene microplates were used as plasma treatment substrates. After O2-He mixed microplasma treatment, 7F2 mouse osteoblastic cells were cultured in the microplates for cell biology studies. We demonstrated the capability of our dual functional platform by applying microplasma in the polystyrene wells and control group (without any treatment) in other wells of the same microplate substrate. The results show that the microplasma treatment changed the surface properties and improved cell attachment. This dual functional freeform system allows for surface patterning and printing of cells, proteins, growth factors, etc. to fabricate three-dimensional tissue constructs.
7
Shi, Yu, Shuiting Ding, and Tian Qiu. "Influence of Inflow Distributions on Swirling Flow in Rotor-Stator Cavity With Centripetal and Centrifugal Superposed Flow." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14176.
Full textAbstract:
Abstract The disk cavity of the rotor-stator system is one of important parts of the aero-engine air system. The rotating speed of airflow determines the relative velocity between the airflow and the rotating assembly, so the maintaining characteristic for swirling flow of the rotor-stator cavity will affect the windage of the rotating assembly in the cavity, and the exporting characteristic for swirling flow of the rotor-stator cavity will affect the windage of the rotating assembly in the downstream chamber. Dual-inlet rotor-stator disk cavity is a typical structure of aero-engine. But there are few reports about the flow structure in the dual-inlet rotor-stator disk cavity in the open literature. In this paper, the influence of inflow distributions on maintaining and exporting characteristics for swirling flow was investigated by numerical simulation, aiming at the interaction between the two inflows. The SST turbulence model was well validated against published experimental results. The simulation results show that there are two flow regions in the rotor-stator cavity from the perspective of meridian plane, and there is a rotating vortex in each flow region. In order to quantify the rotational capacity of the airflow, the angular momentum coefficient was defined. Under different inflow distribution ratios, the sizes of the dominant regions of the two vortices in the cavity get varied, which results in the variation of maintaining and exporting characteristics for swirling flow. It was also found that inflow distributions have the same effect on maintaining and exporting characteristics for swirling flow under different rotational Reynolds numbers and different throughflow coefficients, but the capacity of maintaining and exporting swirling flow are different.
8
Prabhakar, Arun, Stephen Ambrose, and Herve Morvan. "Numerical Investigation of Two Phase Flow in a Dual Drive Booster (DDB)." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90347.
Full textAbstract:
Abstract Recent efforts have been devoted in developing cutting edge methods and technologies to overcome the complications involved in extracting power from the spools in turbofan engines to drive the power systems in aircraft. In a contemporary turbofan engine design, a Dual Drive Booster turbofan (DDBTF) summation gear box is employed to derive power from the low pressure (LP) and high pressure (HP) spools. This paper aims to investigate the scavenging of lubrication oil from the Dual Drive Booster gearbox. It is essential that that the scavenging of oil from the gearbox is efficient to eradicate risks that may arise when oil resides in the gear box for prolonged durations. Longer residence times of oil in the gearbox can lead to rapid oil degradation. Simulations were conducted on a previously optimized geometry and the work in this paper will focus on investigating the effect of different operating conditions on the scavenging performance of the scavenge chamber. The effect of attitude, altitude and the inlet flow rate of oil have been simulated to understand their influence on the oil flow behavior. Emphasis is given on the predicting potential oil churning, recirculation and pooling behaviors in the scavenge chamber that encloses the gear box. Numerical Investigations are carried out using ANSYS Fluent. The Volume of Fluid (VOF) multiphase model is employed to model the multiphase flow arising between air and oil in the system and the effects of turbulence are modelled using the standard k-ϵ model. The computational domain is discretized using a polyhedral grid comprising of 4 million cells which was adopted based on grid independency tests that were conducted prior to the main simulations. Validation against published experimental data for similar flow regimes was also carried out. Results indicate that the scavenging performance is not affected significantly under the various operating conditions and scenarios that were investigated. This is because the effects of the windage outweigh the effects caused by the different operating conditions that are imposed to the scavenge chamber. The windage in the system drives the oil efficiently out from the chamber with the aid of the tangential sump (shown in Figure 4). Oil is distributed in an axially central section of the chamber and the total residence mass of oil is compared and under 0.5 kg for all the cases presented in this paper.
9
Bermejo, Fabio A., and Lesme A. Corredor. "Simulation by Means Computational Fluids Dynamics of the Mixing Process Air-Natural Gas in a Turbocharger Diesel Engine." In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90291.
Full textAbstract:
Diesel buses of public transportation in the main cities of Colombia are formed by turbocharger engines, such machines could operate in dual Diesel-NG way using the gaseous fuel as main energy source and the liquid fuel to pilot ignition of the air-NG mixture previously formed. This research is centered on the studies about formation process of the mixture in the intake system in a turbocharger dual engine. In this study the transport equations are established, it is associated to the fluids which enter to the intake engine during a period of engine operation. This model is simulated by means of CFD tools, using an electronic injector to provide natural gas. Also it is considered the fluidynamic behavior of mixture. Finally an experimental design applied to the simulations is made with the goal of optimize operational conditions of the injector that allow to get the most homogeneous mixture on the inlet runner to one of the cylinders engine. This mixture was obtained injecting natural gas at a pressure of 10 bars and placing the injector as close to the intake manifold.
10
Makida, Mitsumasa, Yoji Kurosawa, and Hideshi Yamada. "Influence of Injection Ratio of Dual-Injection Type Air-Blast Fuel Nozzle on Emission Characteristics Applied to Rectangular Single-Sector Combustor Under Atmospheric Condition." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25988.
Full textAbstract:
In the TechCLEAN project of JAXA, experimental research had been conducted to develop a combustor for a small aircraft engine. The combustor was tuned to show the behavior of the Rich-Lean combustion through tests under atmospheric and practical conditions. Finally, through full annular combustion experiments under practical conditions, the combustor was tuned to reduce NOx emissions to almost 40% of the ICAO CAEP4 standard, also sustaining low CO and THC emissions. In the developing process of above combustors, to simplify the combustor system, air blast type fuel nozzles with single fuel injection and dual swirlers were applied. Successively, in this report, the fuel nozzle is modified to dual fuel injection type with triple swirlers, aiming to control combustion performance under varying load conditions. Fuel is injected from inner and outer injection circuits, and the injection ratio between them is treated as one of the parameters. The combination of swirl direction of the three swirlers is selected at first through ignition and blowout tests. Secondly, spray patterns of the selected fuel nozzle are observed with different fuel injection ratios. Thirdly, the nozzle is applied to a rectangular single-sector combustor, and tested under atmospheric pressure with inlet temperature of 500K. NOx, CO, CO2, THC and O2 compositions in the exhaust gas are measured, and correlation among measured emissions data and fuel injection ratio is estimated to examine the influence of the injection ratio on combustion characteristics of the Rich-Lean type aero engine combustor.