Academic literature on the topic 'Intake flow process'
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Journal articles on the topic "Intake flow process"
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Khalighi, Bahram. "Multidimensional In-Cylinder Flow Calculations and Flow Visualization in a Motored Engine." Journal of Fluids Engineering 117, no. 2 (June 1, 1995): 282–88. http://dx.doi.org/10.1115/1.2817142.
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Multidimensional simulations of coupled intake port/valve and in-cylinder flow structures in a pancake-shape combustion chamber engine are reported. The engine calculations include moving piston, moving intake valve, and valve stem. In order to verify the calculated results, qualitative flow visualization experiments were carried out for the same intake geometry during the induction process using a transient water analog. During the intake process the results of the multidimensional simulation agreed very well with the qualitative flow visualization experiments. An important finding in this study is the generation of a well-defined tumbling flow structure at BDC in the engine. In addition, this tumbling flow is sustained and amplified by the compression process and in turn causes generation of a high turbulence level before TDC. Many interesting features of the in-cylinder flow structures such as tumble, swirl, and global turbulent kinetic energy are discussed.
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Lanson, F., and J. L. Stollery. "Some hypersonic intake studies." Aeronautical Journal 110, no. 1105 (March 2006): 145–56. http://dx.doi.org/10.1017/s0001924000001123.
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Abstract A ‘two dimensional’ air intake comprising a wedge followed by an isentropic compression has been tested in the Cranfield Gun Tunnel at Mach 8·2. These tests were performed to investigate qualitatively the intake flow starting process. The effects of cowl position, Reynolds number, boundary-layer trip and introduction of a small restriction in the intake duct were investigated. Schlieren pictures of the flow on the compression surface and around the intake entrance were taken. Results showed that the intake would operate over the Reynolds number range tested. Tests with a laminar boundary layer demonstrated the principal influence of the Reynolds number on the boundary-layer growth and consequently on the flow structure in the intake entrance. In contrast boundary layer tripping produced little variation in flow pattern over the Reynolds number range tested. The cowl lip position appeared to have a strong effect on the intake performance. The only parameter which prevented the intake from starting was the introduction of a restriction in the intake duct. The experimental data obtained were in good qualitative agreement with the CFD predictions. Finally, these experimental results indicated a good intake flow starting process over multiple changes of parameters.
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Ashhab, M. S. S., A. G. Stefanopoulou, J. A. Cook, and M. B. Levin. "Control of Camless Intake Process—Part II1." Journal of Dynamic Systems, Measurement, and Control 122, no. 1 (July 14, 1998): 131–39. http://dx.doi.org/10.1115/1.482448.
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A model-based control scheme is designed to regulate the cylinder air charge of a camless multicylinder engine for unthrottled operation. The controller consists of a feedforward and an adaptive feedback scheme based on a control-oriented model of the breathing process of an engine equipped with electro-hydraulic springless valvetrain. The nonlinear control scheme is designed to achieve cylinder-to-cylinder balancing, fast cycle-to-cycle response, and minimization of pumping losses. The algorithm uses conventional sensor measurements of intake manifold pressure and mass air flow to the intake manifold, and intake valve duration measurement. Closed-loop simulation results are shown for a four-cylinder engine. [S0022-0434(00)03001-X]
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Fan, Yu, De Xin Liu, and Li Wang. "3D Numerical Simulation on the Variable Swirl Intake Process of Diesel Engine." Applied Mechanics and Materials 273 (January 2013): 143–47. http://dx.doi.org/10.4028/www.scientific.net/amm.273.143.
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To study the flow and swirl characteristics in the variable swirl intake system of a four-valve diesel engine, a numerical simulation with using the three dimensional CFD software AVL-FIRE, was calculated on the intake flow in three types of inlet of the engine. Two swirl-control valve plans are posed and a better plan was selected through the comparative study. The result shows that with a lager valve lift the flow characteristic of spiral inlet is better than that of tangential inlet, and in the opposite case the results are also opposite. The double inlets make the swirl torque increase. When a swirl-control valve is set in the spiral inlet, the variable swirl effect is better, and it ensures better flow capacity and larger swirl ratio range.
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Gaspar, Stefan, and Ján Pasko. "Metal Flow Velocity in an Intake Port in the Process of Die Casting." Advanced Materials Research 705 (June 2013): 177–80. http://dx.doi.org/10.4028/www.scientific.net/amr.705.177.
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The paper deals with metal flow velocity in an intake port in the process of die casting. In the theoretical part the author defines theoretical knowledge from the field of the mold cavity filling regime and the velocity of pressing the melt into the mold cavity. The practical part focuses on the impact of metal flow velocity in an intake port and the filling regime of the pressure foundry mold cavity, related to the former, on the homogeneity of the casting.
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Dong, Zhi Feng, Yin Song, Yong Zheng Gu, and Wei Fu. "Flow Field Numerical Simulation of Diesel Engine Working Process." Advanced Materials Research 468-471 (February 2012): 1781–84. http://dx.doi.org/10.4028/www.scientific.net/amr.468-471.1781.
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The spatial fluid model in diesel engine was built, and multiphase flow transient numerical simulation of working process of diesel engine was done based on computational fluid dynamics. The visualized result of simulation shows the distribution of flow field, press and particle trajectory which can hardly tested direct under the actual working condition. Swirl formed during the intake process and accompanied the whole working process of diesel engine. Keywords: Diesel engine; Numerical simulation; Flow field; Particle trajectory
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Khalighi, B. "Intake Swirl Process Generated by an Engine Head: a Flow Visualization Study." Journal of Engineering for Gas Turbines and Power 113, no. 3 (July 1, 1991): 433–39. http://dx.doi.org/10.1115/1.2906249.
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In-cylinder charge swirl is used in many internal combustion engines to promote combustion. The purpose of this work is to investigate the in-cylinder swirl characteristics generated by an engine head during the induction process by means of flow visualization and Particle Tracking Velocimetry (PTV). The study was carried out for an engine head with a shrouded intake valve in a special single-cylinder transient water analog. The results revealed that the in-cylinder swirl generated by the shroud is characterized by a strong single vortex with its center of rotation eccentric to the cylinder axis. The location of the center rotation differs from plane to plane along the cylinder axis. Furthermore, velocity data obtained for this study suggest that the in-cylinder swirl is not solid body rotation. Finally, the velocity fields were integrated and an equivalent swirl was calculated for the engine under transient conditions.
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Hussain, Ahmad, Mahrukh Mahrukh, and Iqbal Ahmed. "Review The Importance of Seawater Intake and its Treatment Techniques for RO Desalination Plant." Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences 62, no. 3 (November 28, 2019): 215–22. http://dx.doi.org/10.52763/pjsir.phys.sci.62.3.2019.215.222.
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Seawater intake and its treatments are one of the main upstream processes of every seawater desalination plant (RO, ED, MSF, MED). However, the process has turned out to be of utmost importance for reverse osmosis (RO) desalination plant. It is to be sure that sufficient and steady flow and quality of water is available to the RO desalination plant. Prior to RO feed water, the seawater intake pre-treatment process has to be tailored and the quality of seawater intake to be treated either subsurface intake or open surface intakes, particularly when treating open surface intakes seawater (OSIS) with exceedingly unpredictable quality. According to the well-established membrane manufacturer and supplier, the RO membrane warranty and guarantee are depended on seawater intake quality and its pre-treatment. Thus, the current state-of-the-art RO membranes life and performance success for desalination processing depend upon OSIS pre-treatment processing techniques. This article is emphasizing an overview on recent OSIS and its pre-treatment techniques for RO desalination plant.
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Michael, Sean S., Daniel Bickley, Kelly Bookman, Richard Zane, and Jennifer L. Wiler. "Emergency department front-end split-flow experience: ‘physician in intake’." BMJ Open Quality 8, no. 4 (November 2019): e000817. http://dx.doi.org/10.1136/bmjoq-2019-000817.
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BackgroundEmergency department (ED) crowding is a critical problem in the delivery of acute unscheduled care. Many causes are external to the ED, but antiquated operational traditions like triage also contribute. A physician intake model has been shown to be beneficial in a single-centre study, but whether this solution is generalisable is not clear. We aimed to characterise the current state of front-end intake models in a national sample of EDs and quantify their effects on throughput measures.MethodsWe performed a descriptive mixed-method analysis of ED process changes implemented by a cross section of self-selecting institutions who reported 2 years of demographic/operational data and structured process descriptions of any ‘new front-end processes to replace traditional nurse-based triage’.ResultsAmong 25 participating institutions, 19 (76%) provided data. While geographically diverse, most were urban, academic adult level 1 trauma centres. Thirteen (68%) reported implementing a new intake process. All were run by attending emergency physicians, and six (46%) also included advanced practice providers. Daily operating hours ranged from 8 to 16 (median 12, IQR 10.25–15.85), and the majority performed labs, imaging and medication administration and directly discharged patients. Considering each site’s before-and-after data as matched pairs, physician-driven intake was associated with mean decreases in arrival-to-provider time of 25 min (95% CI 13 to 37), ED length of stay 36 min (95% CI 12 to 59), and left before being seen rate 1.2% (95% CI 0.6% to 1.8%).ConclusionsIn this cross section of primarily academic EDs, implementing a physician-driven front-end intake process was feasible and associated with improvement in operational metrics.
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Шмырев, Владимир Федорович. "ОСОБЛИВОСТІ ПРОЕКТУВАННЯ НОСКА ПОВІТРОЗАБІРНИКА ТУРБОВЕНТИЛЯТОРНОГО ДВИГУНА." Open Information and Computer Integrated Technologies, no. 86 (February 14, 2020): 25–36. http://dx.doi.org/10.32620/oikit.2019.86.02.
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Optimization of turbofan engine air intake as well as geometry of intake lip, in-let cross-sectional area and its length is a relevant task in optimizing aerodynamic configuration of an aircraft. It is necessary to ensure a smooth entry of air flow into the engine at all modes of its operation and at various aircraft evolutions while minimizing impact on the overall aerodynamic efficiency of the aircraft. Development of engine air intake was once a very long, routine process that could last for months be-fore design completion, followed by expensive tests on determination of air intake performances on the engine test bench and in flight. Today, we can evaluate performances for a large number of air intake options using design software. The use of computational methods does not exclude tests of air intakes but dramatically reduces their quantity, testing costs and allows designers to focus mainly on the best candidates for air intakes avoiding potential surprises such as shock waves or flow separation caused by a shock wave. Optimal design of the air intake includes determining the right balance between the air intake characteristics, structural load and weight. An over-designed air intake will ultimately be overweight and thus more expensive in terms of flight cost. In a well-designed air intake the Mach number should not exceed 1, in order to avoid a sudden change in static pressure, temperature and density, which can lead to potential shock waves and flow separation caused by a shock wave in all areas throughout the flight. The use of computational fluid dynamics al-lows a better understanding of the conditions under which such adverse events occur. Adjacent to this task is the provision of necessary area on the inside of air intake to ensure sufficient noise absorption generated by the engine fan. The article considers evolution of research on the example of air intake of the D-436 engine of the An-148 aircraft.
Dissertations / Theses on the topic "Intake flow process"
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Falcão, Carlos Eduardo Guex. "Estudo numérico do processo de admissão em um motor de combustão interna utilizando uma metodologia baseada na massa específica pré-condicionada para baixo número de mach com comparação experimental." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/110076.
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Quando ar escoa em regime transiente através do duto de admissão, câmaras e válvulas de um motor de combustão interna, alguns efeitos tais como atrito e forças inerciais têm influência direta sobre a eficiência volumétrica do sistema. O presente trabalho, intitulado “Estudo numérico do processo de admissão em um motor de combustão interna utilizando uma metodologia baseada na massa específica pré-condicionada para baixo número de Mach com comparação experimental”, estuda o processo de admissão em um motor de combustão interna simplificado e objetiva investigar o comportamento pulsante presente no duto de admissão e discutir as predições do escoamento através da válvula de admissão por meio da utilização inédita de uma metodologia numérica baseada na massa específica com précondicionamento para baixo número de Mach, incluindo a modelagem tridimensional do duto de admissão na simulação fluidodinâmica. O movimento da válvula de admissão origina números de Mach moderados durante sua abertura. Com o fechamento, o escoamento é restringido abruptamente e uma série de ondas de pressão se propaga através do fluido com baixo número de Mach. Embora a metodologia baseada na massa específica com précondicionamento para baixo número de Mach pareça atrativa, o estudo do escoamento em processos de admissão não tem sido realizado com a utilização desta metodologia, provavelmente por limitações impostas pela robustez e esforço computacional. De modo a verificar a solução numérica, os resultados são comparados a dados experimentais coletados em uma bancada de fluxo construída especificamente com este propósito. Os resultados numéricos mostram-se satisfatórios e diferentes aspectos do jato originado pelo movimento da válvula são expostos e discutidos.When air flows unsteadily in an internal combustion engine through its inlet pipe, chambers and valves, some effects such as friction and inertial forces have direct influence on the volumetric efficiency of the system. The present work, titled “Numerical study of the intake process of an internal combustion engine using a low Mach preconditioned densitybased method with experimental comparison”, aims to investigate the pulsating phenomena present in an intake pipe of a simplified internal combustion engine and discuss the intake jet flow predictions through the inlet valve by means of the novel use of a low Mach preconditioned density-based method, including the three-dimensional modeling of the intake pipe in the fluid dynamic simulation. Inlet valve movement promotes moderate values of Mach numbers during its opening phase. After closing, the flow is abruptly restricted and a series of pressure waves propagate through the fluid at low Mach numbers. Although low Mach preconditioned density-based method seems to be very attractive in this case, the study of the intake flow process has not been performed using this method, probably due to robustness issues and simulation effort. In order to evaluate the numerical solution, these results are compared to experimental data collected from a flow test bench constructed specifically for this purpose. Numerical results were satisfactory for the amplitudes and the resonance frequencies in the air intake system and different aspects of the jet flow inside the cylinder are exposed and discussed.
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Mahmood, Zulshan. "An experimental investigation of flow processes in dual-intake valve engines." Thesis, King's College London (University of London), 1998. https://kclpure.kcl.ac.uk/portal/en/theses/an-experimental-investigation-of-flow-processes-in-dualintake-valve-engines(18d3d406-ddb3-4794-a976-9cbc37a220c3).html.
Full textBook chapters on the topic "Intake flow process"
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"Urinary system." In Oxford Assess and Progress: Medical Sciences, edited by Jade Chow, John Patterson, Kathy Boursicot, and David Sales. Oxford University Press, 2012. http://dx.doi.org/10.1093/oso/9780199605071.003.0022.
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The kidneys are responsible for maintaining the constant chemical composition of body fluids. This process begins with high-pressure filtration in specialized glomerular capillaries located in the renal cortex. The pressure filtration produces an ultrafiltrate of plasma made up of the water and smaller molecules. As the fluid passes along the renal tubules, water, electrolytes, and non-electrolytes are reabsorbed in the required amounts by a process of selective reabsorption. Some active secretion of unwanted substances also occurs. Following this reabsorption the remaining tubule fluid is passed to the renal pelvis and then down the ureters to the bladder for storage until voided. The effort involved in all this is quite staggering. One-fifth of the daily cardiac output, about 1400 litres of whole blood, including 840 litres of plasma, passes through the kidneys. Of the 540 litres of plasma (the effective renal plasma flow) passing each day through the glomerular capillaries, one-fifth of the plasma water and small molecules are freely filtered at the glomeruli to produce about 170–180 litres per day of glomerular filtrate for the renal tubules. Since typically only 1–2 litres of urine are passed each day (that is about 1 ml per minute) 99 % of the initial filtrate is reabsorbed as the fluid passes along the renal tubules. In oliguria, urine production can fall below 300ml per day, as in severe dehydration. In situations causing polyuria, urine output can rise to several litres per day, or more, as in excessive water intake or untreated diabetes mellitus or diabetes insipidus. The kidney’s main functions are osmoregulation, acid–base balance, and the excretion of waste products of metabolism, notably urea. Osmoregulation is mostly under endocrine control by antidiuretic hormone and the renin–angiotensin–aldosterone system. Acid–base balance is driven mainly by the carbon dioxide partial pressure in renal tubule cells, although kidneys work together with lungs and the control of breathing in overall acid–base balance. The kidney has important endocrine functions. It is the source of erythropoietin, the hormone that stimulates red blood cell production in hypoxia.
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"Multispecies and Watershed Approaches to Freshwater Fish Conservation." In Multispecies and Watershed Approaches to Freshwater Fish Conservation, edited by Gary E. Whelan. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874578.ch3.
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<em>Abstract</em>.—Over much of the history of fisheries management, fisheries biologists challenged with the conservation of degraded fisheries habitats have primarily focused on addressing the symptoms of habitat degradation as opposed to confronting the overarching processes and factors that control fish habitat condition. This is often attributable to the substantial amount of inaccessible or unorganized data that confound resource management decisions. The National Fish Habitat Partnership (NFHP) was formed in 2006 to provide a science-based, holistic, and voluntary-based approach to address the trillions of U.S. dollars in damages that have been inflicted on fish habitats in the United States. The NFHP uses a periodically measured, landscape-level national fish habitat assessment to identify intact systems that need conservation or protection and to assess the root causes of aquatic habitat degradation in altered systems. Categories of data and information contained within the NFHP national fish habitat assessment consist of hydrology, connectivity, water quality, material transport and recruitment, geomorphology, and aquatic organisms’ effect on habitat and energy flow. These processes are critically important in controlling fish habitat condition in all types of aquatic systems, with the key differences being the relative importance and the rates in which the processes and factors operate. Data and information on fish and aquatic organisms and social data are the other components needed to build a comprehensive assessment and decision support framework for fish habitats in the United States. A framework for a model national fish habitat assessment (model assessment) is outlined herein, with each category described in measurable subcomponents that are actionable by fisheries biologists or other aquatic resource managers. Key variables for each process and factor, along with needed data and information for development of dose–response relationships and social data for societal importance indication, are also provided. Although much of the data to fully populate a model assessment are not available currently, it is important to establish a vision for the future. Many of the envisioned data necessary for a model assessment are available on a localized or regional basis to enable the detailed analyses to occur on those spatial scales, allowing the testing of the robustness of the framework. Once the model assessment is fully developed, aquatic resource managers will have a powerful tool to prioritize the trillions of dollars needed to conserve intact and rehabilitate degraded aquatic habitats to build self-sustaining and resilient fish communities. The tool will also help facilitate the NFHP’s goals to maintain intact systems and to move degraded system processes and factors back to within 25% of the expected norms for those watersheds.
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Tinker, Peter B., and Peter Nye. "Solute Transport in the Soil near Root Surfaces." In Solute Movement in the Rhizosphere. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195124927.003.0010.
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We discussed in chapter 4 the movement of solute between small volumes of soil, and in chapter 5 some properties of plant roots and associated hairs, particularly the relation between the rate of uptake at the root surface and the concentration of solute in the ambient solution. In the chapters to follow, we consider the plant root in contact with the soil, and deal with their association in increasingly complex situations; first, when the root acts merely as a sink and, second, when it modifies its relations with the surrounding soil by changing its pH, excreting ions, stimulating microorganisms, or developing mycorrhizas. In this chapter, we take the simplest situation that can be studied in detail, namely, a single intact root alone in a volume of soil so large that it can be considered infinite. The essential transport processes occurring near the root surface are illustrated in figure 6.1. We have examined in chapter 3 the rapid dynamic equilibrium between solutes in the soil pore solution and those sorbed on the immediately adjacent solid surfaces. These sorbed solutes tend to buffer the soil solution against changes in concentration induced by root uptake. At the root surface, solutes are absorbed at a rate related to their concentration in the soil solution at the boundary (section 5.3.2); and the root demand coefficient, αa, is defined by the equation . . . I = 2παaCLa (6.1) . . . where I = inflow (rate of uptake per unit length), a = root radius, CLa = concentration in solution at the root surface. To calculate the inflow, we have to know CLa, and the main topic of this chapter is the relation between CLa, and the soil pore solution concentration CL. The root also absorbs water at its surface due to transpiration (chapter 2) so that the soil solution flows through the soil pores, thus carrying solutes to the root surface by mass flow (convection). Barber et al. (1962) calculated whether the nutrients in maize could be acquired solely by this process, by multiplying the composition of the soil solution by the amount of water the maize had transpired.
Conference papers on the topic "Intake flow process"
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Kim, Myoungjin, and Inyong Ohm. "The Effect of Intake Valve Angle on In-cylinder Flow during Intake and Compression Process." In Powertrain & Fluid Systems Conference and Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2007. http://dx.doi.org/10.4271/2007-01-4045.
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Gunn, E. J., T. Brandvik, and M. J. Wilson. "Fan-Intake Coupling With Conventional and Short Intakes." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-58829.
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Abstract The current trend in civil engine fans towards lower pressure ratio and larger diameter is accompanied by a need to shorten the engine intake length to reduce weight and drag. This paper uses full-annulus, unsteady CFD simulations of two coupled fan-intake configurations to explain the impact of flow field coupling and intake length on fan and intake performance. On-design and off-design operating points are considered at cruise and high angle of attack, respectively. The fan efficiency at cruise is shown to be determined by a trade-off between two effects. Cruise efficiency is reduced by 0.11% with a short intake due to increased potential flow field distortion, which alters the incidence and diffusion of the rotor. This is partially offset by a reduction in casing boundary layer thickness due to lower intake wetted area. At high angle of attack conditions, a short intake leads to increased potential flow field distortion and an earlier onset of intake flow separation due to a higher adverse pressure gradient approaching the fan. Both effects combine to reduce the fan thrust at such conditions, although the fan is shown to remain stable at attack angles up to 35°. The reduction in performance is shown to be dominated by flow separations in the rotor, which increase in size and severity for a given attack angle as the intake length is decreased. The fan is also shown to have a stronger influence on the form of the intake flow field in a short intake, suggesting that it is necessary to model the fan in the intake design process for a successful design.
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Zhong, Frank, Patrick Keough, Kjellb Martel, Richard Delaloye, Curtis Goulet, and Bryan Coates. "SAGD ESP Intake Design Improvement." In SPE Gulf Coast Section Electric Submersible Pumps Symposium. SPE, 2021. http://dx.doi.org/10.2118/204523-ms.
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Abstract One of the major challenges in SAGD Electrical Submersible Pump (ESP) operation is produced water flashing to steam when flowing pressure loss is significant, such as at an ESP intake. "Bottom Feeder" style intakes are a standard SAGD ESP intake which has been applied in the SAGD industry for over a decade. However,it was identified in recent years at ConocoPhillips's (CPC) Surmont Oilsands operations that Bottom Feeder intakes can lead to steam flashing in pump at the right conditions. The flashed steam causes significant cavitation in pump, which in turn causes severe motor load chattering. Further to that, steam locking in the pump can occur, which is called a "no flow event" (NFE) in the SAGD industry. ConocoPhillips and Baker Hughes have been working together to optimize SAGD ESPs by utilizing an integral intake to minimize the pressure loss across the intake ports. This would also streamline the connection between intake and pump housing to minimize pressure loss at these intake flow paths. The improved design has been tested in Surmont successfully, and the integral intake has become an optional intake to be applied in the well cases where steam flashing has been known to cause operation interruptions or ESP damages. This paper will review the process undertaken by CPC and Baker Hughes to study the ESP performance with the bottom feeder intake in comparison to the ESP performance with an integral intake.Design and field data will be presented and reviewed to highlight the performance of each system.
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Luo, Ma-Ji, Zhen Huang, Guo-Hua Chen, and Yuan-Hao Ma. "Flow Simulation in Port and Cylinder of a Small Motorcycle Engine With Inclined Valve." In ASME 2003 Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ices2003-0667.
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The in-cylinder flow of an internal combustion engine has great effect on the major engine performance characteristics. To understand the complex intake phenomena in a small high-speed two-valve-per-cylinder motorcycle engine, a numerical analytic model based on the KIVA-3 code is developed for the three-dimensional transient intake flow, including a moving piston and a moving inclined intake valve. The valve model adopts the body-fitted technique and the dynamic grids induced by the moving valve are automatically generated by the grid remeshing method. Turbulence is represented by k-ε model. Comparison with the measured engine cylinder pressure shows that the simulation result is generally in good agreement with the experiment. The calculated results reveal the formation of the in-cylinder tumble motion, the variation of tumble ratios, turbulence kinetic energy and the cylinder pressure. The effects of engine speeds on the intake process are also investigated. The simulation results provide important information for the design of engine intake system.
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Zhuang, Hanyang, David L. S. Hung, Jie Yang, and Shaoxiong Tian. "Investigation of Swirl Ratio Impact on In-Cylinder Flow in a SIDI Optical Engine." In ASME 2015 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/icef2015-1160.
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Advanced powertrain technologies have improved engine performance with higher power output, lower exhaust emission, and better controllability. Chief among them is the development of spark-ignition direct-injection (SIDI) engines in which the in-cylinder processes control the air flow motion, fuel-air mixture formation, combustion, and soot formation. Specifically, intake air with strong swirl motion is usually introduced to form a directional in-cylinder flow field. This approach improves the mixing process of air and fuel as well as the propagation of flame. In this study, the effect of intake air swirl on in-cylinder flow characteristics was experimentally investigated. High speed particle image velocimetry (PIV) was conducted in an optical SIDI engine to record the flow field on a swirl plane. The intake air swirl motion was achieved by adjusting the opening of a swirl ratio control valve which was installed in one of the two intake ports in the optical engine. Ten opening angles of the swirl ratio control valve were adjusted to produce an intake swirl ratio from 0.55 to 5.68. The flow structures at the same crank angle degree, but under different swirl ratio, were compared and analyzed using proper orthogonal decomposition (POD). The flow dominant structures and variation structures were interpreted by different POD modes. The first POD mode captured the most dominant flow field structure characteristics; the corresponding mode coefficients showed good linearity with the measured swirl ratio at the compression stroke when the flow was swirling and steady. During the intake stroke, strong intake air motion took place, and the structures and coefficients of the first modes varied along different swirl ratio. These modes captured the flow properties affected by the intake swirl motion. Meanwhile, the second and higher modes captured the variation feature of the flow at various crank angle degrees. In summary, this paper demonstrated a promising approach of using POD to interpret the effectiveness of swirl control valve on in-cylinder swirl flow characteristics, providing better understanding for engine intake system design and optimization.
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Yoshizawa, Koudai, Kouji Mori, Yutaka Matayoshi, and Shuji Kimura. "Development of an EGR Distribution Prediction Method Using Three-Dimensional Flow Analysis and its Application." In ASME 2001 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/2001-ice-425.
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Abstract A multidimensional computational fluid dynamics (CED) method has been used to improve the exhaust gas recirculation (EGR) distribution in the intake manifold. Since gas flow in the intake system is affected by intake pulsation caused by the gas exchange process, a pulsation flow simulation is used. A one-dimensional gas exchange calculation is combined with three-dimensional intake gas flow to simulate pulsation flow. This pulsation flow simulation makes it possible to predict the EGR distribution. The gas flow in the intake system was analyzed in detail. It was found that a reverse flow region formed downstream of the throttle valve. The size and shape of the reverse flow region greatly depend on the engine operating conditions. With a conventional EGR system, it is difficult to distribute EGR uniformly under various engine operating conditions. A new EGR system that uses a spiral flow to mix the fresh air and EGR gas has been developed to obtain a uniform EGR distribution. As a result of adopting this system, a uniform EGR distribution is obtained regardless of the engine operating conditions. This spiral flow EGR system was applied to a low-emission vehicle (LEV) put on the Japanese market.
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Werth, David, and Matthew Havice. "A Review of Common Problems Observed in Cooling Water Intakes and the Use of Physical Models to Develop Effective Solutions." In ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-33776.
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Pump intake structures are a necessary component of the cooling water systems for power plants, process and manufacturing facilities, flood control and water/wastewater applications. Large cooling water systems often use substantial sea / river water intakes or cooling towers to provide the required cooling of the process or circulating water. These structures can be very large and often house multiple pump with capacities ranging in size from a few hundred m3/hr to 60,000 m3/hr or more. With such large flow rates care must be taken to ensure uniform flow to the pump to limit vortex activity, vibration, flow induced cavitation and performance problems. In many cases, a physical hydraulic model study is conducted to evaluate the overall approach flow and the performance of the intake. This paper presents a synopsis of several recent physical model studies and a review of recurring problems associated with common design features. This paper takes a closer look at stop log support walls, an intake design feature common to seawater intakes. This wall is often used to minimize the height of the stop logs. In applications with large variations of water level, such as a seawater intake, there are times when the support walls are submerged significantly, resulting in significant flow disturbances. A feature common to cooling towers is the use of 90-degree suction elbows to supply horizontal pumps. A review of short radius vs. long radius elbow performance is presented. Cooling towers often have another common feature which is a significant difference in depth between the cooling tower basin and the pump sump. This results in typical shallow basins and deeper sumps. A common problem is the utilization of minimum pump submergence to set the water levels without reference to the basin invert elevation. A discussion of choked flow conditions in cooling towers is presented. A final discussion is presented regarding cross-flow and the use of concentrated supply channels in cooling tower applications to facilitate the isolation of individual tower cells. This paper presents a synopsis of several recent physical model studies and a review of recurring problems associated with common intake design features. The results of several model studies are presented to demonstrate the negative impacts that these common intake features have on approach flow conditions. The intent of the paper is to provide the design engineer some additional guidance not offered in industry guidelines or standards with the hope of avoiding common problems which can be costly and difficult to remediate after the intake has been constructed.
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Esfahanian, Vahid, Ehsan S. Sobhani, Mehrdad K. Elyasi, and Hamid Karbalaireza. "Predesign of an Internal Combustion Engine Intake Manifold by Numerical Solution of Induction Flow." In ASME 2003 Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ices2003-0647.
Full textAbstract:
A method is proposed to calculate the characteristics of compressible flow in intake manifold of an internal combustion engine, which can be used as an iterative process to determine the main dimensions of the manifold, such as pipes length and diameter, at the primary stages of internal combustion engine design. To calculate the flow field in the pipes, a computer code has been developed to solve the quasi 1-D Euler’s gas dynamics equations using flux-splitting method. Boundary conditions, such as valves, are modeled using experimental data along with some semi-empirical equations. To verify the accuracy of the method, a four cylinder SI engine manifold, with different intake manifold pipe lengths is simulated by the developed computer code and the overall performance characteristics of the engine such as power, torque and volumetric efficiency are obtained and compared with experiments.
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Chiatti, G., and O. Chiavola. "Integrated Multi-Code Prediction of the Unsteady Flow Around Moving Valve and in Engine Intake Systems." In ASME 2001 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/ices2001-137.
Full textAbstract:
Abstract Predictions of the behaviour of flow in duct system are of practical relevance in design procedure, since the performance of internal combustion engine critically depends on the gas dynamic response of the intake port and the cylinder during the induction process.
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Wang, Dapeng, G. Gary Wang, and Greg F. Naterer. "Optimization of Helicopter Air Intake Scoop Design." In ASME 2003 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/detc2003/dac-48801.
Full textAbstract:
In this paper, a global optimization technique based on the Adaptive Response Surface Method (ARSM) is integrated with a Control Volume Finite Element Method (CVFEM) for thermofluid optimization. The objective of the optimization is to improve the thermal effectiveness of an aircraft de-icing strategy by re-designing the cooling bay surface shape. By optimizing objective function in terms of the de-icing strategy and shape of the intake scoop, the best performance of the helicopter engine is achieved. This design problem is implemented on two different physical models. One model involves a heat conduction finite element analysis (FEA) process and the other combines the heat conduction and potential fluid flow FEA processes. Based on the comparison between the ARSM predicted results and the plotted objective function, it is observed that the integrated technique provides an effective method for thermofluid optimization. It also shows that the ARSM has a good flexibility to work with the computationally intensive process, e.g. CVFEM, and, potentially, could be developed and applied to the multidisciplinary design optimization (MDO) due to its open structure.