Gotowa bibliografia na temat „Radial flow compressors”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Zobacz listy aktualnych artykułów, książek, rozpraw, streszczeń i innych źródeł naukowych na temat „Radial flow compressors”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Artykuły w czasopismach na temat "Radial flow compressors"
1
Tan, J., X. Wang, D. Qi i R. Wang. "The effects of radial inlet with splitters on the performance of variable inlet guide vanes in a centrifugal compressor stage". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 225, nr 9 (28.06.2011): 2089–105. http://dx.doi.org/10.1177/0954406211407799.
Pełny tekst źródłaStreszczenie:
Variable inlet guide vanes (VIGVs) can regulate pressure ratio and mass flow at constant rotational speed in centrifugal compressors as a result of inducing a controlled prewhirl in front of impellers. Radial inlets and VIGVs are typical upstream components in front of the first-stage impellers in many industrial centrifugal compressors. However, previous investigations on VIGVs in centrifugal compressors were mostly conducted under the condition of axial inlets, and this study aims to focus on the effects of radial inlet on the VIGVs performance of a centrifugal compressor stage. The axial inlet stage model is compared with the radial inlet stage model with splitters using numerical flow simulation. The flow from the radial inlet was non-uniform in both circumferential and radial directions; thus, the VIGVs, the impeller, the vaneless diffuser, and the return vane channel are modelled with fully 360° passages. The three-dimensional (3D) flow field is numerically simulated at VIGVs setting angles ranging from - 20° to 60°. The overall stage performance parameters are obtained by integrating the field quantities. Though the splitters are equipped in the radial inlet, the overall stage polytropic efficiency decreases by an average of 4 per cent and total pressure ratio decreases by an average of 3.3per cent in comparison with the axial stage model. This can be attributed to the effect of both flow non-uniformity induced by radial inlet and flow loss in the radial inlet at different VIGV setting angles. The flow loss in the radial inlet with splitters is the main reason of the stage performance decrease compared with the flow non-uniformity. The simulation results show that the performance of VIGVs is degraded by its inlet flow distortions resulting from a radial inlet. The results in this study can be applied to centrifugal compressor design and optimization.
2
Bozza, F., A. Senatore i R. Tuccillo. "Thermal Cycle Analysis and Component Aerodesign for Gas Turbine Concept in Low-Range Cogenerating Systems". Journal of Engineering for Gas Turbines and Power 118, nr 4 (1.10.1996): 792–802. http://dx.doi.org/10.1115/1.2816995.
Pełny tekst źródłaStreszczenie:
The authors link together their previous experiences in gas turbine plant analysis and aerodynamic design of radial flow compressors. In recent papers they have introduced a method for the performance estimation of gas turbine engines, based on the prediction of the matching conditions among the several components in the whole operating range. On the other hand they have expressly paid attention to the problem of optimal design of radial flow compressors for satisfactory operation within an assigned operating range. In this paper, the authors present an integrated method, which aims to define the optimal characteristics of a low-power gas turbine engine (i.e., in the range 500–2000 kW). In this case, the radial compressor performance plays an important role as regards gas turbine operation for both power generation and cogeneration applications. The analysis proceeds with the optimization of rotating components (i.e., radial compressor and axial flow turbine) for given thermal cycle parameters. The prescribed objectives of the optimizing procedure are related to performance levels not only at the reference design conditions but also throughout the operating field. A particular emphasis is given to the extension of the field of satisfactory performance for cogeneration applications, with best fitting of mechanical and thermal power requirements. The aerodynamic design of radial flow compressor utilizes a method based on genetic algorithms.
3
Berezin, A. V., A. F. Kuftov i I. B. Shkurikhin. "Blading impellers of radial-flow compressors". Journal of Machinery Manufacture and Reliability 44, nr 7 (grudzień 2015): 616–25. http://dx.doi.org/10.3103/s1052618815070055.
Pełny tekst źródła
4
Prata, A. T., J. R. S. Fernandes i F. Fagotti. "PISTON LUBRICATION IN RECIPROCATING COMPRESSORS". Revista de Engenharia Térmica 1, nr 1 (30.06.2001): 56. http://dx.doi.org/10.5380/reterm.v1i1.3501.
Pełny tekst źródłaStreszczenie:
Piston dynamics plays a fundamental role in two critical processes related to fluid flow in reciprocating compressors. The first is the refrigerant leakage through the radial clearance, which may cause considerable loss in the pumping efficiency of the compressor. The second process is the viscous friction associated with the lubricant film in the radial clearance; certainly a significant factor in the compressor energy consumption. In the present contribution a numerical simulation of the piston movement inside the cylinder of a reciprocating compressor is performed. The compressor considered here is a small hermetic compressor employed in domestic refrigerators. For the problem formulation both the axial and the radial piston motion is considered. In operation, the piston moves up and down along the axis of the cylinder, but the radial oscillatory motion in the cylinder bore, despite being usually small, plays a very important role on the compressor performance and reliability. The compromise between sealing of the gas leakage through the piston-cylinder clearance and the friction losses requires a detailed analysis of the oscillatory motion for a good design. The forces acting on the piston are the hydrodynamic force due to the pressure build up in the oil film (lubrication effects), the force due to the connecting rod, the viscous force associated with the relative motion between the piston and oil, and the force exerted by the gas on the top of the piston. All corresponding moments are also included in the problem formulation of the piston dynamics, in order to determine the piston trajectory, velocity and acceleration at each time step. The hydrodynamic force is obtained from the integration of the pressure distribution on the piston skirt, which, in turn, is determined from a finite volume solution of the time dependent equation that governs the oil flow. A Newton-Raphson procedure was employed in solving the equations of the piston dynamics. The results explored the effects of some design parameters and operating conditions on the stability of the piston, its sealing performance and friction losses. Emphasis was placed on investigating the influence of the pin location, radial clearance and oil viscosity on the piston dynamics. The complexity of the piston movement in reciprocating compressors was demonstrated and the detailed model presented can be employed as an useful tool for engineering design.
5
Eriksson, Lars-Erik. "Simulation of transonic flow in radial compressors". Computer Methods in Applied Mechanics and Engineering 64, nr 1-3 (październik 1987): 95–111. http://dx.doi.org/10.1016/0045-7825(87)90035-1.
Pełny tekst źródła
6
Song, J. W., M. Raheel i A. Engeda. "A compressible flow theory for regenerative compressors with aerofoil blades". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 217, nr 11 (1.11.2003): 1241–57. http://dx.doi.org/10.1243/095440603771665269.
Pełny tekst źródłaStreszczenie:
Regenerative flow compressors (RFCs) are rotodynamic machines capable of producing high heads at very low flowrates. They have very low specific speed and share some of the characteristics of positive displacement machines such as a roots blower, but without the problems of lubrication and wear. They can produce heads equivalent to that of several centrifugal stages from a single rotor with comparable tip speed. The compression process is usually not regarded as efficient. Typically they produce efficiency of less than 50 per cent but still they have found many applications because they allow the use of fluid dynamic compressors in place of positive displacement compressors for duties requiring high heads at low flowrates. There are very few mathematical models in the literature that explain the behaviour of regenerative turbomachines and predict the performance. Most of these models assumed incompressible flow, thus limiting their use to only pumps and blowers. Moreover, they needed extensive experimental support for performance prediction. Hence, it is very interesting from an industrial point of view to find efficient theoretical means that are able to forecast regenerative compressor performances, using easy to find geometric and fluid dynamic parameters. A compressible flow theory is thus presented for the first time in this paper to describe complex three-dimensional corkscrew flow patterns in regenerative compressors. Conventional RFC were designed with radial, non-radial or semicircular impeller blades. In the present investigation, the authors have discussed RFCs with aerofoil blades and an annular flow channel containing a core to direct circulating flow to the blades with a minimum amount of losses. The effects of various geometric elements on the performance of RFCs are studied. All the major sources of losses in blade and channel region are identified. Governing equations for the flow in the compressor are derived and a performance prediction code based on governing equations and loss models is developed. Theoretical performance results are compared with published test data on aerofoil blade RFCs. Based on sensitivity analysis from the code, design changes are suggested for performance improvement.
7
Dutton, J. C., P. Piemsomboon i P. E. Jenkins. "Flowfield and Performance Measurements in a Vaned Radial Diffuser". Journal of Fluids Engineering 108, nr 2 (1.06.1986): 141–47. http://dx.doi.org/10.1115/1.3242553.
Pełny tekst źródłaStreszczenie:
The flow characteristics of a vaned diffuser typical of those currently used in centrifugal compressors have been determined experimentally by using a static diffuser test rig. The vortex test vehicle (VTV) portion of this rig was used to simulate the essential features of the flow leaving the impeller of an actual compressor. The mean flow phenomena at the diffuser entrance and the static pressure recovery along the diffuser passage have been determined. In addition, the flow angle and Mach number distributions at several key locations throughout the diffuser channel have been obtained. The most notable feature of the diffuser flowfield is the high degree of nonuniformity in the inlet/leading edge region.
8
Prata, A. T., J. R. S. Fernandes i F. Fagotti. "Dynamic Analysis of Piston Secondary Motion for Small Reciprocating Compressors". Journal of Tribology 122, nr 4 (4.04.2000): 752–60. http://dx.doi.org/10.1115/1.1314603.
Pełny tekst źródłaStreszczenie:
Piston dynamics plays a fundamental role in two critical processes related to fluid flow in reciprocating compressors. The first is the gas leakage through the radial clearance, which may cause considerable loss in the pumping efficiency of the compressor. The second process is the viscous friction associated with the lubricant film in the radial clearance. In the present contribution a numerical simulation is performed for a ringless piston inside the cylinder of a reciprocating compressor, including both the axial and the radial piston motion. The compressor considered here is a small hermetic compressor employed in domestic refrigerators, with the radial clearance between piston and cylinder filled with lubricant oil. In operation, the piston moves up and down along the axis of the cylinder, but the radial oscillatory motion in the cylinder bore, despite being usually small, plays a very important role on the compressor performance and reliability. The compromise between oil leakage through the piston-cylinder clearance and the friction losses requires a detailed analysis of the oscillatory motion for a good design. All corresponding forces and moments are included in the problem formulation of the piston dynamics in order to determine the piston trajectory, velocity and acceleration at each time step. The hydrodynamic force is obtained from the integration of the pressure distribution on the piston skirt, which, in turn, is determined from a finite volume solution of the time dependent equation that governs the oil flow. A Newton-Raphson procedure was employed in solving the equations of the piston dynamics. The results explored the effects of some design parameters and operating conditions on the stability of the piston, the oil leakage, and friction losses. Emphasis was placed on investigating the influence of the pin location, radial clearance and oil viscosity on the piston dynamics. [S0742-4787(11)00301-8]
9
Rodgers, C. "Impingement Starting and Power Boosting of Small Gas Turbines". Journal of Engineering for Gas Turbines and Power 107, nr 4 (1.10.1985): 821–27. http://dx.doi.org/10.1115/1.3239817.
Pełny tekst źródłaStreszczenie:
The technology of high-pressure air or hot-gas impingement from stationary shroud supplementary nozzles onto radial outflow compressors and radial inflow turbines to permit rapid gas turbine starting or power boosting is discussed. Data are presented on the equivalent turbine component performance for convergent/divergent shroud impingement nozzles, which reveal the sensitivity of nozzle velocity coefficient with Mach number and turbine efficiency with impingement nozzle admission arc. Compressor and turbine matching is addressed in the transient turbine start mode with the possibility of operating these components in braking or reverse flow regimes when impingement flow rates exceed design.
10
Han, Fenghui, Zhe Wang, Yijun Mao, Jiajian Tan i Wenhua Li. "Flow Control of Radial Inlet Chamber and Downstream Effects on a Centrifugal Compressor Stage". Applied Sciences 11, nr 5 (1.03.2021): 2168. http://dx.doi.org/10.3390/app11052168.
Pełny tekst źródłaStreszczenie:
Radial inlet chambers are widely used in various multistage centrifugal compressors, although they induce extra flow loss and inlet distortions. In this paper, the detailed flow characteristics inside the radial inlet chamber of an industrial centrifugal compressor have been numerically investigated for flow control and performance improvement. First, the numerical results are validated against the experimental data, and flow conditions inside the inlet chambers with different structures are compared. They indicate that, in the non-guide vane scheme, sudden expansions, tangential flows and flow separations in the spiral and annular convergent channels are the major causes of flow loss and distortions, while using guide vanes could introduce additional flow impacts, separations and wakes. Based on the flow analysis, structure improvements have been carried out on the radial inlet chamber, and an average increase of 4.97% has been achieved in the inlet chamber efficiencies over different operating conditions. However, the results further reveal that the increases in the performance and overall flow uniformity just in the radial inlet chamber do not necessarily mean a performance improvement in the downstream components, and the distribution of the positive tangential velocity at the impeller inlet might be a more essential factor for the efficiency of the whole compressor.
Rozprawy doktorskie na temat "Radial flow compressors"
1
Pelton, Robert John. "One-Dimensional Radial Flow Turbomachinery Performance Modeling". Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2192.pdf.
Pełny tekst źródła
2
Reyes, Belmonte Miguel Ángel. "Contribution to the Experimental Characterization and 1-D Modelling of Turbochargers for IC Engines". Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/34777.
Pełny tekst źródłaStreszczenie:
At the end of the 19th Century, the invention of the Internal Combustion Engine
(ICE) marked the beginning of our current lifestyle. Soon after the first ICE
patent, the importance of increasing air pressure upstream the engine cylinders was
revealed. At the beginning of the 20th Century turbo-machinery developments (which
had started time before), met the ICE what represented the beginning of turbocharged
engines. Since that time, the working principle has not fundamentally changed. Nevertheless,
stringent emissions standards and oil depletion have motivated engine developments;
among them, turbocharging coupled with downsized engines has emerged
as the most feasible way to increase specific power while reducing fuel consumption.
Turbocharging has been traditionally a complex problem due to the high rotational
speeds, high temperature differences between working fluids (exhaust gases,
compressed air, lubricating oil and cooling liquid) and pulsating flow conditions. To
improve current computational models, a new procedure for turbochargers characterization
and modelling has been presented in this Thesis. That model divides turbocharger
modelling complex problem into several sub-models for each of the nonrecurring
phenomenon; i.e. heat transfer phenomena, friction losses and acoustic
non-linear models for compressor and turbine. A series of ad-hoc experiments have
been designed to aid identifying and isolating each phenomenon from the others. Each
chapter of this Thesis has been dedicated to analyse that complex problem proposing
different sub-models.
First of all, an exhaustive literature review of the existing turbocharger models
has been performed. Then a turbocharger 1-D internal Heat Transfer Model (HTM)
has been developed. Later geometrical models for compressor and turbine have been
proposed to account for acoustic effects. A physically based methodology to extrapolate
turbine performance maps has been developed too. That model improves
turbocharged engine prediction since turbine instantaneous behaviour moves far from
the narrow operative range provided in manufacturer maps. Once each separated
model has been developed and validated, a series of tests considering all phenomena
combined have been performed. Those tests have been designed to check model
accuracy under likely operative conditions.
The main contributions of this Thesis are the development of a 1-D heat transfer
model to account for internal heat fluxes of automotive turbochargers; the development
of a physically-based turbine extrapolation methodology; the several tests
campaigns that have been necessary to study each phenomenon isolated from others
and the integration of experiments and models in a comprehensive characterization
procedure designed to provide 1-D predictive turbocharger models for ICE calculation.Reyes Belmonte, MÁ. (2013). Contribution to the Experimental Characterization and 1-D Modelling of Turbochargers for IC Engines [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34777
TESIS
3
Nolan, Sean Patrick Rock. "Effect of radial transport on compressor tip clearance flow structures and enhancement of stable flow range". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32435.
Pełny tekst źródłaStreszczenie:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2005.Includes bibliographical references (p. 66-67).
The relation between tip clearance flow structure and axial compressor stall is interrogated via numerical simulations, to determine how casing treatment can result in improved flow range. Both geometry changes and flow field body forces are used as diagnostics to assess the hypothesis that the radial transport of momentum out of the tip region, and the consequent decrease in streamwise momentum in this region, is a key aspect of the flow. The radial velocity responsible for this transport is a result of the flow field set up by the tip clearance vortex. Altering the position of the tip clearance vortex can alter the amount of streamwise momentum lost due to radial transport and hence increase the compressor flow range. Circumferential grooves improve the flow range in the manner described above. In the presence of such a groove the radial velocity profile along the passage can be altered so that that the radial transport of streamwise momentum is decreased. The flow fields associated with grooves at different axial positions, and of different depths, are also examined, along with previous research on circumferential grooves, and it is shown that these are in accord with the hypothesis.
by Sean Nolan
S.M.
4
Ferreira, Adriano Domingos. "Simulação do escoamento bifásico da mistura óleo-refrigerante através da folga radial de compressores rotativos de pistão rolante /". Ilha Solteira : [s.n.], 2006. http://hdl.handle.net/11449/88881.
Pełny tekst źródłaStreszczenie:
Orientador: José Luiz GascheBanca: André Luiz Seixlack
Banca: Paulo Eduardo Lopes Barbieri
Resumo: Devido à solubilidade mútua entre o fluido refrigerante e o fluido lubrificante usados em sistemas de refrigeração por compressão de vapor, eles formam uma mistura homogênea que influencia tanto os processos de transferência de calor no evaporador e no condensador, como os processos de lubrificação e de selagem de vazamentos no interior do compressor. O vazamento de refrigerante através da folga radial de compressores rotativos de pistão rolante é de particular importância para o bom desempenho do compressor, uma vez que ele influencia significativamente a eficiência volumétrica do compressor, chegando a somar cerca de 30% das perdas totais de refrigerante. No presente trabalho foram desenvolvidos modelos de escoamento de misturas óleo-refrigerante através desta folga, incluindo a mudança de fase do refrigerante devida à variação da sua solubilidade no lubrificante. A solução da equação da energia constitui uma evolução do processo de modelagem deste escoamento em relação aos modelos até então desenvolvidos. Quatro modelos diferentes foram usados para simular o escoamento: modelo de escoamento bifásico homogêneo isotérmico, modelo de escoamento bifásico isotérmico com formação de espuma, modelo de escoamento bifásico homogêneo não-isotérmico e modelo de escoamento bifásico homogêneo não-isotérmico com termo de força inercial. O estudo foi realizado para três misturas óleo-refrigerante: óleo éster Freol a10 e refrigerante R134a, óleo éster EMKARATE RL10H e refrigerante R134a e óleo mineral SUNISO 1 GS e refrigerante R12. Para todos os modelos e misturas, realizou-se um estudo paramétrico envolvendo as principais variáveis do problema: pressão de entrada, temperatura de entrada, vazão de mistura e valor da folga mínima... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Due to the mutual solubility between the refrigerant and lubricant of refrigeration systems using mechanical compression of vapor, they form a homogeneous mixture which influences the heat transfer processes in the evaporator and condenser as well as the compressor lubrication and refrigerant leakage. The refrigerant leakage through the radial clearance of rolling piston compressors plays an important role to the volumetric efficiency in this type of compressor, in which it represents about 30% of the total refrigerant loss. In the present work several models to predict the lubricant-refrigerant mixture flow through this clearance, including the refrigerant phase change due to the reduction of the refrigerant solubility in the lubricant, are developed. Four different models were developed to simulate the flow: isothermal homogeneous two-phase flow, isothermal two-phase flow with foam formation, non-isothermal homogeneous two-phase flow and non-isothermal homogeneous two-phase flow containing inertial force. The simulations were performed for three mixtures: ester oil Freol a10-refrigerant R134a, ester oil EMKARATE RL10H-refrigerant R134a, and mineral oil SUNISO 1 GS-refrigerant R12. The influences of the inlet pressure, inlet temperature, mixture mass flow rate, and minimal clearance were analyzed for all mixtures. The results showed that it is important to consider the foam formation, the inertial force, and the solution of the energy equation in the flow modeling. Concerning the volumetric efficiency of the compressor the ester oil Freol a10-R134a was the best mixture because it produced the lowest refrigerant leakage.
Mestre
5
Ferreira, Adriano Domingos [UNESP]. "Simulação do escoamento bifásico da mistura óleo-refrigerante através da folga radial de compressores rotativos de pistão rolante". Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/88881.
Pełny tekst źródłaStreszczenie:
Made available in DSpace on 2014-06-11T19:23:39Z (GMT). No. of bitstreams: 0
Previous issue date: 2006-11-27Bitstream added on 2014-06-13T18:10:04Z : No. of bitstreams: 1
ferreira_ad_me_ilha.pdf: 1079421 bytes, checksum: dcb82443da323ec46bf3bd207a17001c (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Devido à solubilidade mútua entre o fluido refrigerante e o fluido lubrificante usados em sistemas de refrigeração por compressão de vapor, eles formam uma mistura homogênea que influencia tanto os processos de transferência de calor no evaporador e no condensador, como os processos de lubrificação e de selagem de vazamentos no interior do compressor. O vazamento de refrigerante através da folga radial de compressores rotativos de pistão rolante é de particular importância para o bom desempenho do compressor, uma vez que ele influencia significativamente a eficiência volumétrica do compressor, chegando a somar cerca de 30% das perdas totais de refrigerante. No presente trabalho foram desenvolvidos modelos de escoamento de misturas óleo-refrigerante através desta folga, incluindo a mudança de fase do refrigerante devida à variação da sua solubilidade no lubrificante. A solução da equação da energia constitui uma evolução do processo de modelagem deste escoamento em relação aos modelos até então desenvolvidos. Quatro modelos diferentes foram usados para simular o escoamento: modelo de escoamento bifásico homogêneo isotérmico, modelo de escoamento bifásico isotérmico com formação de espuma, modelo de escoamento bifásico homogêneo não-isotérmico e modelo de escoamento bifásico homogêneo não-isotérmico com termo de força inercial. O estudo foi realizado para três misturas óleo-refrigerante: óleo éster Freol a10 e refrigerante R134a, óleo éster EMKARATE RL10H e refrigerante R134a e óleo mineral SUNISO 1 GS e refrigerante R12. Para todos os modelos e misturas, realizou-se um estudo paramétrico envolvendo as principais variáveis do problema: pressão de entrada, temperatura de entrada, vazão de mistura e valor da folga mínima...
Due to the mutual solubility between the refrigerant and lubricant of refrigeration systems using mechanical compression of vapor, they form a homogeneous mixture which influences the heat transfer processes in the evaporator and condenser as well as the compressor lubrication and refrigerant leakage. The refrigerant leakage through the radial clearance of rolling piston compressors plays an important role to the volumetric efficiency in this type of compressor, in which it represents about 30% of the total refrigerant loss. In the present work several models to predict the lubricant-refrigerant mixture flow through this clearance, including the refrigerant phase change due to the reduction of the refrigerant solubility in the lubricant, are developed. Four different models were developed to simulate the flow: isothermal homogeneous two-phase flow, isothermal two-phase flow with foam formation, non-isothermal homogeneous two-phase flow and non-isothermal homogeneous two-phase flow containing inertial force. The simulations were performed for three mixtures: ester oil Freol a10-refrigerant R134a, ester oil EMKARATE RL10H-refrigerant R134a, and mineral oil SUNISO 1 GS-refrigerant R12. The influences of the inlet pressure, inlet temperature, mixture mass flow rate, and minimal clearance were analyzed for all mixtures. The results showed that it is important to consider the foam formation, the inertial force, and the solution of the energy equation in the flow modeling. Concerning the volumetric efficiency of the compressor the ester oil Freol a10-R134a was the best mixture because it produced the lowest refrigerant leakage.
6
Guillou, Erwann. "Flow Characterization and Dynamic Analysis of a Radial Compressor with Passive Method of Surge Control". University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321371782.
Pełny tekst źródła
7
Anhê, Junior Sérgio Antônio [UNESP]. "Investigação numérica e experimental do escoamento em válvulas de compressores herméticos". Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/88864.
Pełny tekst źródłaStreszczenie:
Made available in DSpace on 2014-06-11T19:23:39Z (GMT). No. of bitstreams: 0
Previous issue date: 2010-06-28Bitstream added on 2014-06-13T20:30:31Z : No. of bitstreams: 1
anhejunior_sa_me_ilha.pdf: 2550289 bytes, checksum: 4299d702522bdb3a4b51de625099c77e (MD5)Fundação de Ensino Pesquisa e Extensão de Ilha Solteira (FEPISA)
O presente trabalho refere-se à investigação experimental e numérica do escoamento em difusores radiais, que são usados como modelos de representação de sistemas de válvulas de compressores de refrigeração. Uma bancada experimental é projetada, construída e validada para medir a distribuição de pressão, sobre o disco frontal de um difusor radial de razão de diâmetro 3, para números de Reynolds de 1500 a 9000 e afastamento entre os discos frontal e anterior variando de 0,415mm a 0,705mm aproximadamente. Paralelamente, desenvolve-se um código computacional, baseado na metodologia de Volumes Finitos para malhas desencontradas, para simular o escoamento na geometria do difusor radial. O código computacional é primeiramente validado por meio dos resultados experimentais obtidos da bancada construída. Após sua validação, o código é usado para analisar o escoamento em um difusor de razão de diâmetro igual a 1,4, para números de Reynolds variando de 500 a 2500 e afastamento entre discos na fixa de 0,125 a 1,0mm. Os resultados numéricos mostram o surgimento de recirculação extendendo-se em toda região do difusor. Além disso, os resultados de perfil de pressão sobre o disco frontal fornecem forças e quedas totais de pressão no difusor que aumentam com o número de Reynolds e afastamento entre disco. Esse comportamento produz um ponto de mínima área efetiva de força localizado na faixa de , para números de Reynolds variando de 500 a 1500. Para número de Reynolds mais elevados, , a área efetiva de força sempre aumenta com o aumento do afastamento entre discos. A área efetiva de escoamento, outro parâmetro de interesse para a simulação do compressor, apresenta um crescimento linear com o afastamento entre discos, independentemente do número de Reynolds avaliado.
In this work, an experimental and numerical investigation of the flow in radial diffusers representing the valve system of refrigeration compressor is accomplished. An experimental bench is designed, build, and validated allowing the measurement of the pressure distribution on the frontal disk surface of a radial diffuser with diameter ratio equal to 3, for Reynolds number varying from 1500 to 9000 and distances between disks in the ranges of 0.415 to 0.705mm. In addition, a computational code based on the Finite Volume Methodology for staggered mesh is developed in order to simulate the flow though the radial diffuser. The computational code is firstly validated by using the experimental data obtained from the experimental bench. After its validation, the code is used for analyzing the flow through a radial diffuser with diameter ratio equal to 1.4, for Reynolds numbers varying from 500 to 2500 and distance between disks in the range of 0.125 a 1.0 mm. The numerical results showed recirculation regions extending through the whole diffuser for the majority of the analyzed cases. The pressure profiles on the frontal disk surface produce forces and total pressure drops through the diffuser that increase with both Reynolds number and distance between disks. There is a minimum effective force area in the range of , for Reynolds numbers varying from 500 a 1500. For higher Reynolds numbers, , the effective force area always increases for increasing distance between disks. The effective flow area, another parameter used for simulating the compressor, increases linearly with the distance between disks, independently of the Reynolds number.
8
Salameh, Georges. "Caractérisation expérimentale d’une turbine de suralimentation automobile et modélisation de ses courbes caractéristiques de fonctionnement". Thesis, Ecole centrale de Nantes, 2016. http://www.theses.fr/2016ECDN0006/document.
Pełny tekst źródłaStreszczenie:
La diminution de la cylindrée ou le downsizing du moteur est potentiellement l'une des stratégies les plus efficaces pour améliorer la consommation de carburant et diminuer les émissions polluantes. Dans le domaine de la suralimentation, la simulation est limitée par les caractéristiques de fonctionnement des turbines fournies par les constructeurs. Une extrapolation précise et fiable des cartographies turbine est donc l’objectif de cette thèse. Une étude expérimentale sur une turbine radiale d’un turbocompresseur est effectuée avec différentes techniques pour mesurer la cartographie turbine la plus large possible. Les mesures sont effectuées sur un banc turbocompresseur classique avec différentes températures d'entrée turbine. Puis une technique de gavage en entrée et en sortie compresseur est testée. Le compresseur est ensuite remplacé par un autre compresseur à roue inversée qui peut aider la turbine à tourner et même l’entrainer. Les débits les plus faibles et même les débits négatifs sont mesurés. Un banc turbine électromécanique a également été développé, mais n’a pas pu donner de résultats satisfaisants à cause de problèmes techniques mais des évolutions à venir restent prometteuses. Les diverses techniques expérimentales testées ont aussi permis de mesurer le rendement isentropique de la turbine et le rendement mécanique du turbocompresseur. Finalement, plusieurs modèles d’extrapolation des courbes caractéristiques turbine ont été testés et confrontés aux résultats expérimentauxEngine downsizing is potentially one of the most effective strategies being explored to improve fuel economy and reduce emissions. In the field of turbocharging,simulation is limited by the operating characteristics of turbines supplied by the manufacturers. An accurate and precise extrapolation of the turbine performance maps is the main aim of this study. An experimental study was done on a radial turbine of a turbocharger with different techniques to measure the wider turbine performance map possible. Measurements were done on a classic turbocharger test bench with different turbine inlet temperatures. Then air was blown to the compressor inlet and exit: it is the compressor “gavage”. The compressor is then replaced with another one with are versed rotor: this compressor can help the turbine turn and even drive it itself. The lowest mass flow rates are measured even the negative ones. An electromechanical turbine test bench was developed but did not work correctly because of technical problems but future developments are promising. The various experimental techniques used allowed also the measurement of the turbine isentropic efficiency and the turbocharger mechanical efficiency. Finally, many extrapolation models of the turbine performance maps were tested and compared to the experimental results
9
Zygmont, Martin. "Reverzační turbokompresor". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229815.
Pełny tekst źródłaStreszczenie:
The diploma thesis consists of a theoretical part, which deals with the description of reversing turbocharger and its components. The following part is devoted to calculating the radial-axial compressor and turbine. It also performs a calculation of gear box and characteristics of the turbine.
10
Anhê, Júnior Sergio Antônio. "Investigação numérica e experimental do escoamento em válvulas de compressores herméticos /". Ilha Solteira : [s.n.], 2010. http://hdl.handle.net/11449/88864.
Pełny tekst źródłaStreszczenie:
Orientador: José Luiz GascheBanca: André Luiz Seixlack
Banca: Odenir de Almeida
Resumo: O presente trabalho refere-se à investigação experimental e numérica do escoamento em difusores radiais, que são usados como modelos de representação de sistemas de válvulas de compressores de refrigeração. Uma bancada experimental é projetada, construída e validada para medir a distribuição de pressão, sobre o disco frontal de um difusor radial de razão de diâmetro 3, para números de Reynolds de 1500 a 9000 e afastamento entre os discos frontal e anterior variando de 0,415mm a 0,705mm aproximadamente. Paralelamente, desenvolve-se um código computacional, baseado na metodologia de Volumes Finitos para malhas desencontradas, para simular o escoamento na geometria do difusor radial. O código computacional é primeiramente validado por meio dos resultados experimentais obtidos da bancada construída. Após sua validação, o código é usado para analisar o escoamento em um difusor de razão de diâmetro igual a 1,4, para números de Reynolds variando de 500 a 2500 e afastamento entre discos na fixa de 0,125 a 1,0mm. Os resultados numéricos mostram o surgimento de recirculação extendendo-se em toda região do difusor. Além disso, os resultados de perfil de pressão sobre o disco frontal fornecem forças e quedas totais de pressão no difusor que aumentam com o número de Reynolds e afastamento entre disco. Esse comportamento produz um ponto de mínima área efetiva de força localizado na faixa de , para números de Reynolds variando de 500 a 1500. Para número de Reynolds mais elevados, , a área efetiva de força sempre aumenta com o aumento do afastamento entre discos. A área efetiva de escoamento, outro parâmetro de interesse para a simulação do compressor, apresenta um crescimento linear com o afastamento entre discos, independentemente do número de Reynolds avaliado.
Abstract: In this work, an experimental and numerical investigation of the flow in radial diffusers representing the valve system of refrigeration compressor is accomplished. An experimental bench is designed, build, and validated allowing the measurement of the pressure distribution on the frontal disk surface of a radial diffuser with diameter ratio equal to 3, for Reynolds number varying from 1500 to 9000 and distances between disks in the ranges of 0.415 to 0.705mm. In addition, a computational code based on the Finite Volume Methodology for staggered mesh is developed in order to simulate the flow though the radial diffuser. The computational code is firstly validated by using the experimental data obtained from the experimental bench. After its validation, the code is used for analyzing the flow through a radial diffuser with diameter ratio equal to 1.4, for Reynolds numbers varying from 500 to 2500 and distance between disks in the range of 0.125 a 1.0 mm. The numerical results showed recirculation regions extending through the whole diffuser for the majority of the analyzed cases. The pressure profiles on the frontal disk surface produce forces and total pressure drops through the diffuser that increase with both Reynolds number and distance between disks. There is a minimum effective force area in the range of , for Reynolds numbers varying from 500 a 1500. For higher Reynolds numbers, , the effective force area always increases for increasing distance between disks. The effective flow area, another parameter used for simulating the compressor, increases linearly with the distance between disks, independently of the Reynolds number.
Mestre
Książki na temat "Radial flow compressors"
1
Chung-hua, Wu. A general theory of two-and three-dimensional rotational flow in subsonic and transonic turbomachines. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1993.
Znajdź pełny tekst źródła
2
Chung-hua, Wu. A general theory of two-and three-dimensional rotational flow in subsonic and transonic turbomachines. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1993.
Znajdź pełny tekst źródła
3
Center, Lewis Research, red. A three-dimensional axisymmetric calculation procedure for turbulent flows in a radial vaneless diffuser. Cleveland, Ohio: Lewis Research Center, 1985.
Znajdź pełny tekst źródła
4
Center, Lewis Research, red. A three-dimensional axisymmetric calculation procedure for turbulent flows in a radial vaneless diffuser. Cleveland, Ohio: Lewis Research Center, 1985.
Znajdź pełny tekst źródła
5
Center, Lewis Research, red. A three-dimensional axisymmetric calculation procedure for turbulent flows in a radial vaneless diffuser. Cleveland, Ohio: Lewis Research Center, 1985.
Znajdź pełny tekst źródła
6
Center, Lewis Research, red. A three-dimensional axisymmetric calculation procedure for turbulent flows in a radial vaneless diffuser. Cleveland, Ohio: Lewis Research Center, 1985.
Znajdź pełny tekst źródła
7
A three-dimensional axisymmetric calculation procedure for turbulent flows in a radial vaneless diffuser. Cleveland, Ohio: Lewis Research Center, 1985.
Znajdź pełny tekst źródła
8
A three-dimensional axisymmetric calculation procedure for turbulent flows in a radial vaneless diffuser. Cleveland, Ohio: Lewis Research Center, 1985.
Znajdź pełny tekst źródłaCzęści książek na temat "Radial flow compressors"
1
Enghardt, Lars, Armin Faßbender i Jakob Hurst. "Sound Sources of Radial Compressors—A Numerical Study on the Outlet Side". W Flinovia—Flow Induced Noise and Vibration Issues and Aspects-II, 71–84. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76780-2_5.
Pełny tekst źródła
2
Veress, Árpád, i René Van den Braembussche. "New Approach to Radial Compressor Return Channel Design". W Modelling Fluid Flow, 389–406. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-08797-8_27.
Pełny tekst źródła
3
Evers, W., M. Heinrich, I. Teipel i A. R. Wiedermann. "Flow Simulation in a High-Loaded Radial Compressor". W Notes on Numerical Fluid Mechanics (NNFM), 461–75. Wiesbaden: Vieweg+Teubner Verlag, 1996. http://dx.doi.org/10.1007/978-3-322-89849-4_33.
Pełny tekst źródła
4
Heinrich, M., i I. Teipel. "Flow Simulation in an Aerodynamic Diffusor of a High Loaded Radial Compressor using Different Turbulence Models". W Advances in Fluid Mechanics and Turbomachinery, 39–56. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-72157-1_4.
Pełny tekst źródła
5
"Efficiency Definitions for Compressors". W Radial Flow Turbocompressors, 106–34. Cambridge University Press, 2021. http://dx.doi.org/10.1017/9781108241663.006.
Pełny tekst źródła
6
"Throughflow Code for Radial Compressors". W Radial Flow Turbocompressors, 480–527. Cambridge University Press, 2021. http://dx.doi.org/10.1017/9781108241663.017.
Pełny tekst źródła
7
"Radial Impeller Flow Calculation". W Design and Analysis of Centrifugal Compressors, 61–111. Chichester, UK: John Wiley & Sons, Ltd, 2018. http://dx.doi.org/10.1002/9781119424086.ch3.
Pełny tekst źródła
8
"Compressor Instability and Control". W Radial Flow Turbocompressors, 565–600. Cambridge University Press, 2021. http://dx.doi.org/10.1017/9781108241663.019.
Pełny tekst źródłaStreszczenia konferencji na temat "Radial flow compressors"
1
Pauer, Reinhard, i Norbert Mu¨ller. "Impeller Design for Radial and Mixed Flow Compressors". W ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61926.
Pełny tekst źródłaStreszczenie:
An impeller design algorithm implemented in a computer code is presented. It can be used for designing radial and mixed flow impellers for compressors, blowers and fans. The implemented algorithm allows finding suitable impeller geometries considering fluid mechanical and technological aspects. Based on the input of main design parameters for the stage (like tip diameter, rotational speed, through flow, and specific energy transfer), first the feasibility of the given combination of input values is checked, and possible design ranges are determined (like for outlet blade angles, inlet diameter, and outlet width). After choosing the final design parameter within the possible range, a mean line blading is generated. Then the algorithm allows optimizing the blading geometry, velocity distribution, and blade loading by changing the mean streamline. The mean line blading then serves as a basis for generating the complete 3D blading, distributing the blade loading in a way that favorable velocity distributions are obtained throughout the impeller and that the obtained blade geometry is acceptable. Finally the blading generated according to fluid mechanical aspects can be adapted to technological constrains by changing geometric parameters and overlaying a thickness distribution. During this process the velocity distributions are always re-evaluated using the streamline curvature algorithm by Stanitz und Prain. Despite friction is neglected, experience has shown that the obtained results allow a good evaluation of the aerodynamic quality of the impeller design.
2
Cozzi, Lorenzo, Filippo Rubechini, Matteo Giovannini, Michele Marconcini, Andrea Arnone, Andrea Schneider i Pio Astrua. "Capturing Radial Mixing in Axial Compressors With CFD". W ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-75942.
Pełny tekst źródłaStreszczenie:
Due to the generally high stage and blade count, the current standard industrially adopted to perform numerical simulations on multistage axial compressors is the steady-state analysis based on the Reynolds-averaged Navier-Stokes approach (RANS), where the coupling between adjacent rows is handled by means of mixing planes. In addition to the well-known limitations of a steady-state picture of the flow, namely its inherent inability to capture the potential interaction and the wakes from the upstream blades, there is another flow feature which is lost through a mixing-plane, and which is believed to be a major accountable for the radial mixing: the transport of stream-wise vorticity. Streamwise vorticity arises throughout a compressor for various reasons, mainly associated with secondary and tip-clearance flows. A strong link does exist between the strain field associated with the transported vortices and the mixing augmentation: the strain field increases both the area available for mixing and the local gradients in fluid properties, which provide the driving potential for mixing itself. Especially for the rear stages of a multistage axial compressor, due to high clearances and low aspect ratios, only accounting for the development along the meridional path of secondary and clearance flow structures it is possible to properly predict the spanwise mixing. In this work, the results of steady and unsteady RANS simulations on the high-pressure section of an industrial heavy-duty axial compressor are presented and compared with experimental data acquired during a test campaign. Adopting an unsteady full-annulus URANS approach, the enhanced radial mixing in the rear stages of the compressor is properly captured, obtaining a really good agreement with experimental data both in terms of total temperature and pressure outlet radial distributions. On the contrary, with a steady-state modelling, the radial transport is strongly underestimated, leading to results with marked departures from experiments. Examining what occurs across the inter-row interfaces for RANS and URANS solutions, a possible explanation for this underestimation is provided. In particular, as the stream-wise vorticity associated with clearance flows is one of the main drivers of radial mixing, restraining it by pitch-averaging the flow at mixing planes of a steady-state analysis is the reason why this simplified approach is not able to properly predict the radial transport of fluid properties in the rear part of the axial compressor.
3
Casey, Michael, Christof Zwyssig i Chris Robinson. "The Cordier Line for Mixed Flow Compressors". W ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22549.
Pełny tekst źródłaStreszczenie:
The specific speed and specific diameter of radial, mixed and axial flow compressors can be plotted in a Cordier diagram, and the best compressors then lie in a relatively narrow band, known as the Cordier or Balje line. This line exhibits a distinctive s-shape, and it is shown in this paper that this is due to the variation of the centrifugal effect on the pressure rise of the different compressor types. A new equation for the Cordier line in the mixed flow region based on the pressure rise coefficient is developed and calibrated with data from mixed flow pumps and ventilators. Together with other empirical relationships for the expected efficiency as a function of the specific speed this provides some useful new guidelines for the preliminary design of mixed flow compressors. These guidelines are then examined by carrying out a preliminary design of a high-speed mixed-flow micro-compressor that is analyzed using CFD and tested to justify the approach.
4
Kaldellis, J. K., P. D. Ktenidis i D. E. Kodossakis. "Energy Exchange and Secondary Losses Prediction in High Speed Axial and Radial Compressors". W ASME 1990 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1990. http://dx.doi.org/10.1115/90-gt-229.
Pełny tekst źródłaStreszczenie:
In this paper an extension of our secondary flow calculation method is presented in order to estimate the energy exchange and the secondary losses in axial and radial compressors. Although it is well known today that end-wall shear layers play a major role in the performance of the compressors, there are only few secondary flow methods able to predict realistically the behaviour of real machines. For this purpose a new theory was developed which extends Mellor’s basic principles and uses our previous work, including the complete form of meridional vorticity transport equation. A coherent model for the real work exchange between the fluid and the machine has been developed, as well as for the distribution of secondary losses, not only at the compressor’s exit but also at every station through the machine. An expression for the added work due to the secondary field is also given. Finally the influence of secondary losses in the overall efficiency is well estimated. This work has been successfully applied to a highly loaded compressor cascade, as well as to a transonic axial compressor and to a radial one-stage one. Comparison between theoretical and experimental results is also presented.
5
Spraker, Wilbur A. "Clearance and Reynolds Number Effects on the Efficiency of Radial Flow Compressors". W International Congress & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1991. http://dx.doi.org/10.4271/910417.
Pełny tekst źródła
6
Qian, Zeng. "Numerical Studies of Diffuser Inlet Configurations for Small Flow Rate Radial Compressors". W ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50612.
Pełny tekst źródłaStreszczenie:
A computational fluid dynamics (CFD) study is presented to predict the impact of a number of inlet configuration features to the performance of centrifugal compressors diffusers. These features include impeller-diffuser alignment, diffuser inlet edge radius, impeller tip gap width, flow angle, and tip leakage/injection. In small flow rate centrifugal compressors the distance between hub and shroud at impeller discharge could be so small that due to thermal expansion and component mechanical tolerance stacking accurate alignment between the impeller and the diffuser is difficult to achieve. The impeller tip gap is relatively big and the leakage percentage is high. These are some of the major factors that contribute to the high loss and low efficiency of small flow rate compressors. In order to reduce the sensitivity of diffuser performance to misalignment, the designers often make a round, i.e., a radius of curvature in the meridional plane, on the diffuser entrance edges. The designers also need to properly determine the impeller tip gap width and estimate the impact of tip leakage. In this study the influences of these design features are investigated. Axisymmetric models are used for the flow inside a vaneless diffuser. Groups of cases are calculated with focus on the impact of each individual feature in a multiple configuration variable environment. In the cases calculated the impeller discharge is positioned in incremental axial misalignment relative to the diffuser. Different sizes of impeller tip gap, diffuser inlet rounds, and quantity of leakage or injection through the gap are calculated. The influences of the skewed impeller discharge velocity field on each of these configuration variations are investigated. The results are compared and the optimized configurations with balanced misalignment tolerance and peak performance are discussed. The study found that diffuser inlet round radius φ has a significant impact on the diffuser performance. At the optimum value of φ the diffuser has the highest tolerance to misalignment and the minimum penalty in pressure recovery. For a given impeller/diffuser misalignment there exists an optimum impeller tip gap width. Small quantities of impeller tip gap leakage or injection always has an adverse effect on diffuser performance. When the meridional flow angle offsets from radial direction the optimum impeller/diffuser alignment shifted as well.
7
Lüdtke, Klaus. "Centrifugal Process Compressors: Radial vs. Tangential Suction Nozzles". W ASME 1985 International Gas Turbine Conference and Exhibit. American Society of Mechanical Engineers, 1985. http://dx.doi.org/10.1115/85-gt-80.
Pełny tekst źródłaStreszczenie:
Experimental investigations were conducted on a radial and a tangential inlet duct to an industrial centrifugal compressor. The tangential nozzle will replace the conventional radial nozzle if a block foundation is used with no pipes allowed on the upper casing half. Models were air tested with and without suction elbows. The tangential duct was tested with various positions of the shaped flow splitter and with variable intake rib angles with the objective to minimize distortions of axial and circumferential velocity profiles and the moment of momentum in the annular eye opening of the impeller. An optimum configuration for the tangential duct was found with smooth profiles and eliminated global vortex at the exit annulus.
8
Bartelt, Michael, Thomas Kwitschinski, Thomas Ceyrowsky, Daniel Grates i Joerg R. Seume. "Experimental and Numerical Investigation of Different Rectangular Volute Geometries for Large Radial Compressors". W ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46296.
Pełny tekst źródłaStreszczenie:
Increases on mass flow rates of modern radial process compressors result on larger machine components. In particular, the dimensions of the outlet volutes increase strongly, resulting in disproportionately large machines whose technical feasibility is restricted due to technological and economical reasons. A resulting aim is to design modern radial compressors much more compact, while improving the efficiency and the pressure ratio. Therefore, the present experimental investigation addresses the compressor behaviour for reduced dimensions of rectangular volutes. Furthermore, the experimental setups are numerically modelled and different operating points are simulated with a commercial CFD-Code. A rectangular, external reference volute is equipped with differently shaped blockage-inlays and the global compressor parameters are measured for all variants. Additionally, the pressure and velocity distributions of the local flow field are determined experimentally for varying mass flow ratios at different circumferentially distributed volute layers. The decrease of the volute cross-section results in a reduction of the compressor map width especially at high mass flow rates. Recommendations are given for designing compact volutes of large radial compressors.
9
Saladino, Anthony J., i Stephen J. Bielecki. "Streamlining of the Radial Inlet Design Process for Centrifugal Compressors". W ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-39590.
Pełny tekst źródłaStreszczenie:
A radial compressor inlet represents an asymmetric and highly complex flow path, with high potential for flow disturbance. Due to the large computational resources and long lead times required for CFD analysis of such components, this resource has historically been reserved for conceptual or prototype designs. In the production environment, where compressor internals are often customized to a particular application, designers generally rely on geometric analysis of the flowpath. Low priority historically given to centrifugal inlet design is adequately illustrated in “mud etching” of the flow field in a retrofitted radial compressor inlet. An estimate of the potential for efficiency gain through inlet optimization, based on CFD predicted loss coefficient, is presented. It is noted that poor exit flow profiles can negatively impact performance, as well. Ill effects may include efficiency loss in downstream components, mechanical vibration, and compressor control issues. With continual improvement in CFD processing speed, the prospect of applying CFD based optimization techniques to production radial inlet designs becomes more feasible. In this investigation, CFD analysis is performed on an existing radial inlet design and validated with data from a flow visualization test rig. The subject inlet design is subsequently optimized through CFD analysis, with detailed attention being given to the impact of adjusting various geometric characteristics. A number of independent geometric parameters, which are determined to have significant impact on loss coefficient, are condensed into an optimization parameter. This optimization parameter serves as a preliminary indicator of design quality. Alternative brute force design methods are time prohibitive and may not provide the designer with feedback required to effectively alter geometry. Details of the CFD modeling and subsequent validation testing of the baseline inlet design are given. CFD results for a variety of modified inlet designs are presented. An overview of the optimization parameter and its application to a new radial inlet design are also presented. The potential for such an optimization parameter to limit design iteration is illustrated. Although additional refinement is suggested, the subject optimization parameter shows potential to direct the designer away from low efficiency designs.
10
Sato, K., i L. He. "A Numerical Study on Performances of Centrifugal Compressor Stages With Different Radial Gaps". W ASME Turbo Expo 2000: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/2000-gt-0462.
Pełny tekst źródłaStreszczenie:
A numerical study of 3D unsteady flows in centrifugal compressor stages solving the Navier-Stokes equations is presented. The emphasis is on the effect of the radial gap between blade rows on the aerodynamic performance. In the numerical tests, Krain’s centrifugal impeller was combined with a DCA (Double Circular Arc) type radial vaned diffuser. The compressor stages with three settings of radial gap ranging from 5 to 15 percent of the impeller trailing edge radius are configured and unsteady flow simulations are carried out to compare the time-averaged efficiencies. The performance predictions show that the efficiency is deteriorated if the radial gap between blade rows is reduced with intensified blade row interaction, which is in contradiction to the general trend for axial compressor stages. In the centrifugal compressors tested, wake chopping by diffuser vanes, which usually benefits efficiency in axial compressor stages, causes unfavourable wake compression through the diffuser passages to deteriorate the efficiency.
Raporty organizacyjne na temat "Radial flow compressors"
1
Beavers. L51557 Pressure Losses in Compressor Station Yard Pipework - Phase II. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), czerwiec 1987. http://dx.doi.org/10.55274/r0010277.
Pełny tekst źródłaStreszczenie:
The economic assessment of piping layout in compressor station yards relies on accurate prediction of pressure losses within the network. Methods currently used to predict pressure losses in station pipe work are unreliable. As a result inadequate and inaccurate information is being used when making economic assessments of piping layout and in the prediction of operating costs. By improving the design process substantial economic advantages may be gained in balancing pressure losses and compressor inlet flow conditions against investment in piping and components. Currently the existing data concentrate on isolated component losses and there is a lack of reliable data on interaction of adjacent components frequently present in compressor yard layouts. Thus, in order to produce a comprehensive guide to compressor yard losses, there was considerable incentive to quantify these interactions. This report details the experimental work to provide reliable pressure loss data for an engineer's design handbook. The tee tests include the effect of branch to run radius and two area ratios. A total of 36 bend/tee combinations were tested. Results are presented as overall bend/tee pressure loss coefficients and interaction corrections. The latter are used in the design handbook. The factors affecting bend and tee performance are discussed. Bend/tee interactions are explained qualitatively in terms of interaction of the pressure and flow distributions within the components. The work covers pressure losses in bends, close coupled bend/bend combinations, tees (combining and dividing) and tee/bend combinations.
2
Jay. L51710 Active Noise Silencing. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), styczeń 1994. http://dx.doi.org/10.55274/r0010333.
Pełny tekst źródłaStreszczenie:
Many natural gas compressor stations which were previously located away from residential areas are now being encroached upon by surrounding building developments. Furthermore, an increased awareness of community noise issues has proved to be the impetus for investigating and developing more effective noise control methods and treatments for natural gas compressor facilities. This project investigates the feasibility of applying Active Noise Cancellation (ANC) to the exhaust of a large, internal-combustion reciprocating type engine. Large reciprocating internal combustion engines pose significant challenges for the noise control engineer. In the case of the engines employed at Tennessee Gas Pipeline Company Compressor Station 229, these engines radiate extremely low frequency exhaust noise into the surrounding environs. These engines produce discrete frequencies in the exhaust spectra with a particularly strong component at 26.5 Hz, which corresponds to the fundamental firing frequency (the 5.0 rotational order) of the engine; significant attenuation of the raw exhaust noise can be particularly difficult due to the sound power and spectral content. Traditional methods would necessitate a very large silencer in order to realize improved attenuation of the exhaust noise, relative to the existing silencer. Measurements were conducted at the error microphone location, at 1.0 meter from the exhaust outlet and at the property line. At a distance of 1.0 meter the WNCT integrated active / passive silencer yielded 84.5 dBA (92.3 dBL) while the original equipment silencer yielded 92.7 dBA (98.8 dBL). Band-limited (DC - 200 Hz) measurements were taken at the error microphone location; control off (WNCT passive - only): 109.8 dBL overall, 107.7 dBL 26.5 Hz component. With control on (WNCT active + passive) at the same position overall noise was 99.7 dBL with the 26.5 Hz component reading 89.1 dBL. Far-field A-weighted reductions were inconclusive due to the presence of other contributing noise sources possessing similar noise characteristics. Flow resistance measurements indicated that back pressure had been reduced by 95% relative to the original equipment silencer through the use of the integrated WNCT active / passive silencer.