The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform

Ce Yang - One of the best experts on this subject based on the ideXlab platform.

  • Numerical investigation of the superimposed effects on stator wake oscillation in an axial-radial Combined Compressor
    Journal of Thermal Science, 2014
    Co-Authors: Ben Zhao, Liangjun Hu, Mi Zhou, Ce Yang, Jizhong Zhang
    Abstract:

    The superimposed influences of the blade rows in a multistage Compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial Combined Compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T (moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from up- and downstream moving rows were superimposed with the “positive peak-negative peak” type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with “positive peak-positive peak” type wave due to the impact of the interaction between the two moving blade rows.

  • Numerical investigation of the superimposed effects on stator wake oscillation in an axial-radial Combined Compressor
    Journal of Thermal Science, 2014
    Co-Authors: Ben Zhao, Liangjun Hu, Mi Zhou, Ce Yang, Jizhong Zhang
    Abstract:

    The superimposed influences of the blade rows in a multistage Compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial Combined Compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T (moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from up- and downstream moving rows were superimposed with the "positive peak-negative peak" type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with "positive peak-positive peak" type wave due to the impact of the interaction between the two moving blade rows. © 2014 Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg.

  • Numerical investigation on superimposed effect of wake/potential interaction in axial-radial Combined Compressor
    Hangkong Dongli Xuebao Journal of Aerospace Power, 2013
    Co-Authors: Y.-h. Liu, D.-z. Lao, Ben Zhao, Ce Yang, C C Ma
    Abstract:

    Three-dimensional unsteady viscous numerical simulation was conducted on an axial-radial Combined Compressor to study the interaction characteristic of wake/potential and downstream potential effects on the mid stator vane. The axial rotor/stator vane, axial rotor/impeller and stator vane/impeller interaction effects on the impeller inlet angle were also investigated by using the effect factor split of the Combined Compressor unsteady flow. The results show that upstream wake and downstream potential lead to reinforce/suppress effect while coupling in the mid vane passage. Due to the different phases of axial rotor/stator vane, axial rotor/impeller and stator vane/impeller interaction, work fluid at impeller inlet encounters distortion, which directly affects the amplitude of inlet angle.

  • Stator Wake Research in Axial-Radial Combined Compressor With Inlet Distortion
    Volume 6C: Turbomachinery, 2013
    Co-Authors: Du Li, Dazhong Lao, Ben Zhao, Ce Yang
    Abstract:

    A Combined Compressor consisting of an axial rotor, a stator and a centrifugal rotor was used in a vehicle engine turbocharger because of its better performance compared with a single stage Compressor under space restrictions. There have been many studies on the inlet distortion effect on multistage axial Compressors; however, few studies have been performed for axial-radial Combined Compressors. To investigate stator wake characteristics, an axial-radial Compressor was unsteadily simulated with three-dimensional Reynolds averaged Navier-Stokes equations by "domain-scaling" the rotor/stator interface method under uniform, circumferential distorted and Combined distorted total pressure inlet conditions. In addition to the axial-radial configuration, the unsteady method of analysis was applied to a stand-alone axial stage by the same unsteady method. A comparison shows that at the vane stator outlet, a radial distortion is formed and different total pressure loss occurs at different spans. The circumferential interfaces between the distorted and non-distorted regions generate different flow characteristics due to different pitchwise pressure gradient directions and the absence of a downstream rotor. The stator wake causes more flow loss in the distorted case but less flow angle fluctuation compared to the uniform inlet condition. The downstream potential effect and inlet distortion creates strong pressure pulsation at the stator blade surface. A stator wake oscillation characteristics study shows disturbing effects on the stator wake from the upstream axial rotor, and the downstream radial rotor acts differently both spanwise and pitchwise. Copyright © 2013 by ASME.

  • Effects of Blade Counts and Clocking on the Unsteady Profile Pressure Distribution in an Axial-Radial Combined Compressor
    2013
    Co-Authors: Ben Zhao, Liangjun Hu, Ce Yang, Dazhong Lao
    Abstract:

    A new hypothesis is presented for the superimposed effects of the blade pressure distribution in a multistage Compressor. The effects of the unsteady pressure fluctuations on the blade surface are separated into three groups. The influences of the upstream or downstream rotors can be obtained by numerical simulation for the R/S or S/R configuration; the data produced by all the influences can be obtained from the R/S/R configuration. The effects of the blade counts and clocking on the superimposed effects, acting on the profile pressure distribution, are studied using a special data analysis method that had been previously developed by the authors. The results indicate that the blade counts of the upstream and downstream rotors determine the periods of the unsteady pressure fluctuations on the stator surface. The clocking moving blade rows modulate the relative superimposed phases and interactions between two rotors such that the unsteady pressure fluctuates with different amplitudes on the surface of the stator blade.

Ben Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Numerical investigation of the superimposed effects on stator wake oscillation in an axial-radial Combined Compressor
    Journal of Thermal Science, 2014
    Co-Authors: Ben Zhao, Liangjun Hu, Mi Zhou, Ce Yang, Jizhong Zhang
    Abstract:

    The superimposed influences of the blade rows in a multistage Compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial Combined Compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T (moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from up- and downstream moving rows were superimposed with the “positive peak-negative peak” type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with “positive peak-positive peak” type wave due to the impact of the interaction between the two moving blade rows.

  • Numerical investigation of the superimposed effects on stator wake oscillation in an axial-radial Combined Compressor
    Journal of Thermal Science, 2014
    Co-Authors: Ben Zhao, Liangjun Hu, Mi Zhou, Ce Yang, Jizhong Zhang
    Abstract:

    The superimposed influences of the blade rows in a multistage Compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial Combined Compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T (moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from up- and downstream moving rows were superimposed with the "positive peak-negative peak" type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with "positive peak-positive peak" type wave due to the impact of the interaction between the two moving blade rows. © 2014 Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg.

  • Numerical investigation on superimposed effect of wake/potential interaction in axial-radial Combined Compressor
    Hangkong Dongli Xuebao Journal of Aerospace Power, 2013
    Co-Authors: Y.-h. Liu, D.-z. Lao, Ben Zhao, Ce Yang, C C Ma
    Abstract:

    Three-dimensional unsteady viscous numerical simulation was conducted on an axial-radial Combined Compressor to study the interaction characteristic of wake/potential and downstream potential effects on the mid stator vane. The axial rotor/stator vane, axial rotor/impeller and stator vane/impeller interaction effects on the impeller inlet angle were also investigated by using the effect factor split of the Combined Compressor unsteady flow. The results show that upstream wake and downstream potential lead to reinforce/suppress effect while coupling in the mid vane passage. Due to the different phases of axial rotor/stator vane, axial rotor/impeller and stator vane/impeller interaction, work fluid at impeller inlet encounters distortion, which directly affects the amplitude of inlet angle.

  • Stator Wake Research in Axial-Radial Combined Compressor With Inlet Distortion
    Volume 6C: Turbomachinery, 2013
    Co-Authors: Du Li, Dazhong Lao, Ben Zhao, Ce Yang
    Abstract:

    A Combined Compressor consisting of an axial rotor, a stator and a centrifugal rotor was used in a vehicle engine turbocharger because of its better performance compared with a single stage Compressor under space restrictions. There have been many studies on the inlet distortion effect on multistage axial Compressors; however, few studies have been performed for axial-radial Combined Compressors. To investigate stator wake characteristics, an axial-radial Compressor was unsteadily simulated with three-dimensional Reynolds averaged Navier-Stokes equations by "domain-scaling" the rotor/stator interface method under uniform, circumferential distorted and Combined distorted total pressure inlet conditions. In addition to the axial-radial configuration, the unsteady method of analysis was applied to a stand-alone axial stage by the same unsteady method. A comparison shows that at the vane stator outlet, a radial distortion is formed and different total pressure loss occurs at different spans. The circumferential interfaces between the distorted and non-distorted regions generate different flow characteristics due to different pitchwise pressure gradient directions and the absence of a downstream rotor. The stator wake causes more flow loss in the distorted case but less flow angle fluctuation compared to the uniform inlet condition. The downstream potential effect and inlet distortion creates strong pressure pulsation at the stator blade surface. A stator wake oscillation characteristics study shows disturbing effects on the stator wake from the upstream axial rotor, and the downstream radial rotor acts differently both spanwise and pitchwise. Copyright © 2013 by ASME.

  • Effects of Blade Counts and Clocking on the Unsteady Profile Pressure Distribution in an Axial-Radial Combined Compressor
    2013
    Co-Authors: Ben Zhao, Liangjun Hu, Ce Yang, Dazhong Lao
    Abstract:

    A new hypothesis is presented for the superimposed effects of the blade pressure distribution in a multistage Compressor. The effects of the unsteady pressure fluctuations on the blade surface are separated into three groups. The influences of the upstream or downstream rotors can be obtained by numerical simulation for the R/S or S/R configuration; the data produced by all the influences can be obtained from the R/S/R configuration. The effects of the blade counts and clocking on the superimposed effects, acting on the profile pressure distribution, are studied using a special data analysis method that had been previously developed by the authors. The results indicate that the blade counts of the upstream and downstream rotors determine the periods of the unsteady pressure fluctuations on the stator surface. The clocking moving blade rows modulate the relative superimposed phases and interactions between two rotors such that the unsteady pressure fluctuates with different amplitudes on the surface of the stator blade.

Du Li - One of the best experts on this subject based on the ideXlab platform.

  • Stator Wake Research in Axial-Radial Combined Compressor With Inlet Distortion
    Volume 6C: Turbomachinery, 2013
    Co-Authors: Du Li, Dazhong Lao, Ben Zhao, Ce Yang
    Abstract:

    A Combined Compressor consisting of an axial rotor, a stator and a centrifugal rotor was used in a vehicle engine turbocharger because of its better performance compared with a single stage Compressor under space restrictions. There have been many studies on the inlet distortion effect on multistage axial Compressors; however, few studies have been performed for axial-radial Combined Compressors. To investigate stator wake characteristics, an axial-radial Compressor was unsteadily simulated with three-dimensional Reynolds averaged Navier-Stokes equations by "domain-scaling" the rotor/stator interface method under uniform, circumferential distorted and Combined distorted total pressure inlet conditions. In addition to the axial-radial configuration, the unsteady method of analysis was applied to a stand-alone axial stage by the same unsteady method. A comparison shows that at the vane stator outlet, a radial distortion is formed and different total pressure loss occurs at different spans. The circumferential interfaces between the distorted and non-distorted regions generate different flow characteristics due to different pitchwise pressure gradient directions and the absence of a downstream rotor. The stator wake causes more flow loss in the distorted case but less flow angle fluctuation compared to the uniform inlet condition. The downstream potential effect and inlet distortion creates strong pressure pulsation at the stator blade surface. A stator wake oscillation characteristics study shows disturbing effects on the stator wake from the upstream axial rotor, and the downstream radial rotor acts differently both spanwise and pitchwise. Copyright © 2013 by ASME.

  • The influence of frequency and clocking on stator wake in an axial-radial Combined Compressor
    Kung Cheng Je Wu Li Hsueh Pao Journal of Engineering Thermophysics, 2013
    Co-Authors: Ben Zhao, M.-x. Qi, Ce Yang, Du Li, J. Z. Zhang
    Abstract:

    The unsteady flow in a Combined Compressor, which consists of axial flow and radial impellers, was simulated numerically at mass flow of 1.15 kg/s and speed of 60 kr/min (design point), and an in-depth analysis of the related factors caused stator wake flow variability was performed. This paper explored the major factors decided stator wake unsteady flow, as well as found out a method to control the stator wake unsteady flow. The research results indicated that: the blade passing frequencies of upstream and downstream moving blade rows decided the periodicity of stator wake unsteady flow; and when the upstream rotor had the same blade passing frequency as downstream rotor, the clocking could modify stator wake unsteady flow and the relative flow angle at inlet of radial rotor.

  • Investigation of Separating and Utilizing the Influences of Up- and Downstream Blade Rows
    Volume 8: Turbomachinery Parts A B and C, 2012
    Co-Authors: Ben Zhao, Liangjun Hu, Mi Zhou, Ce Yang, Du Li
    Abstract:

    The superimposed influences of the blade rows in multistage Compressor are important, because different matching status of upstream and downstream blades can result in significant differences in unsteady pressure fluctuations. Numerical investigation of the unsteady pressure distributions on axial stator blade, which affect by the axial rotor in the upstream and the radial rotor in the downstream, was performed in an axial-radial Combined Compressor. Unsteady pressure fluctuation was investigated. When rotors have equal blade numbers, the unsteady pressure fluctuates periodically versus time within T time. On contrast, it fluctuates irregularly within T time when they have different blade numbers. A model-split subtraction method to separate the influences of the individual blade rows on the profile pressure distribution of the axial stator was presented. Analysis from the rotor-stator configuration showed that the unsteady pressure fluctuation response caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady pressure fluctuations were influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the unsteady pressure could be clearly separated and quantified. High amplitudes were observed when the influences from up- and downstream moving rows were superimposed with “positive peak-positive peak” type wave. In contrast, the amplitudes were decreased by the opposite superimposition phase (“positive peak-negative peak” type wave). Clocking investigations were carried out for two goals. One is to show the isolated influence from up- or downstream rotor by eliminating down- or upstream influence components. This is called clocking subtraction method. The other one is to change the relative superimposed phase of influences from the surrounding blade rows. Thus, the physical mechanism of the unsteady pressure fluctuation amplitude modulation by means of clocking was put forward.

  • investigation on centrifugal impeller in an axial radial Combined Compressor with inlet distortion
    Journal of Thermal Science, 2011
    Co-Authors: Du Li, Mingxu Qi, Mi Zhou, Ben Zhao, Ce Yang, Jizhong Zhang
    Abstract:

    Assembling an axial rotor and a stator at centrifugal Compressor upstream to build an axial-radial Combined Compressor could achieve high pressure ratio and efficiency by appropriate size augment. Then upstream potential flow and wake effect appear at centrifugal impeller inlet. In this paper, the axial-radial Compressor is unsteadily simulated by three-dimensional Reynolds averaged Navier-Stokes equations with uniform and circumferential distorted total pressure inlet condition to investigate upstream effect on radial rotor. The results show that span-wise nonuniform total pressure distribution is generated and radial and circumferential Combined distortion is formed at centrifugal rotor inlet. The upstream stator wake deflects to rotor rotation direction and decreases with blade span increases. Circumferential distortion causes different separated flow formations at different pitch positions. The tip leakage vortex is suppressed in centrifugal blade passages. Under distorted inlet condition, flow direction of centrifugal impeller leading edge upstream varies evidently near hub and shroud but varies slightly at mid-span. In addition, Compressor stage inlet distortion produces remarkable effect on blade loading of centrifugal blade both along chordwise and pitchwise.

  • Investigation on centrifugal impeller in an axial-radial Combined Compressor with inlet distortion
    Journal of Thermal Science, 2011
    Co-Authors: Du Li, Mingxu Qi, Mi Zhou, Ben Zhao, Ce Yang, Jizhong Zhang
    Abstract:

    Assembling an axial rotor and a stator at centrifugal Compressor upstream to build an axial-radial Combined Compressor could achieve high pressure ratio and efficiency by appropriate size augment. Then upstream potential flow and wake effect appear at centrifugal impeller inlet. In this paper, the axial-radial Compressor is unsteadily simulated by three-dimensional Reynolds averaged Navier-Stokes equations with uniform and circumferential distorted total pressure inlet condition to investigate upstream effect on radial rotor. The results show that span-wise nonuniform total pressure distribution is generated and radial and circumferential Combined distortion is formed at centrifugal rotor inlet. The upstream stator wake deflects to rotor rotation direction and decreases with blade span increases. Circumferential distortion causes different separated flow formations at different pitch positions. The tip leakage vortex is suppressed in centrifugal blade passages. Under distorted inlet condition, flow direction of centrifugal impeller leading edge upstream varies evidently near hub and shroud but varies slightly at mid-span. In addition, Compressor stage inlet distortion produces remarkable effect on blade loading of centrifugal blade both along chordwise and pitchwise. © 2010 Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg.

Jizhong Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Numerical investigation of the superimposed effects on stator wake oscillation in an axial-radial Combined Compressor
    Journal of Thermal Science, 2014
    Co-Authors: Ben Zhao, Liangjun Hu, Mi Zhou, Ce Yang, Jizhong Zhang
    Abstract:

    The superimposed influences of the blade rows in a multistage Compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial Combined Compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T (moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from up- and downstream moving rows were superimposed with the “positive peak-negative peak” type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with “positive peak-positive peak” type wave due to the impact of the interaction between the two moving blade rows.

  • Numerical investigation of the superimposed effects on stator wake oscillation in an axial-radial Combined Compressor
    Journal of Thermal Science, 2014
    Co-Authors: Ben Zhao, Liangjun Hu, Mi Zhou, Ce Yang, Jizhong Zhang
    Abstract:

    The superimposed influences of the blade rows in a multistage Compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial Combined Compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T (moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by up- and downstream blade rows. With the model-split subtraction method, the up- and downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from up- and downstream moving rows were superimposed with the "positive peak-negative peak" type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with "positive peak-positive peak" type wave due to the impact of the interaction between the two moving blade rows. © 2014 Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg.

  • investigation on centrifugal impeller in an axial radial Combined Compressor with inlet distortion
    Journal of Thermal Science, 2011
    Co-Authors: Du Li, Mingxu Qi, Mi Zhou, Ben Zhao, Ce Yang, Jizhong Zhang
    Abstract:

    Assembling an axial rotor and a stator at centrifugal Compressor upstream to build an axial-radial Combined Compressor could achieve high pressure ratio and efficiency by appropriate size augment. Then upstream potential flow and wake effect appear at centrifugal impeller inlet. In this paper, the axial-radial Compressor is unsteadily simulated by three-dimensional Reynolds averaged Navier-Stokes equations with uniform and circumferential distorted total pressure inlet condition to investigate upstream effect on radial rotor. The results show that span-wise nonuniform total pressure distribution is generated and radial and circumferential Combined distortion is formed at centrifugal rotor inlet. The upstream stator wake deflects to rotor rotation direction and decreases with blade span increases. Circumferential distortion causes different separated flow formations at different pitch positions. The tip leakage vortex is suppressed in centrifugal blade passages. Under distorted inlet condition, flow direction of centrifugal impeller leading edge upstream varies evidently near hub and shroud but varies slightly at mid-span. In addition, Compressor stage inlet distortion produces remarkable effect on blade loading of centrifugal blade both along chordwise and pitchwise.

  • Investigation on centrifugal impeller in an axial-radial Combined Compressor with inlet distortion
    Journal of Thermal Science, 2011
    Co-Authors: Du Li, Mingxu Qi, Mi Zhou, Ben Zhao, Ce Yang, Jizhong Zhang
    Abstract:

    Assembling an axial rotor and a stator at centrifugal Compressor upstream to build an axial-radial Combined Compressor could achieve high pressure ratio and efficiency by appropriate size augment. Then upstream potential flow and wake effect appear at centrifugal impeller inlet. In this paper, the axial-radial Compressor is unsteadily simulated by three-dimensional Reynolds averaged Navier-Stokes equations with uniform and circumferential distorted total pressure inlet condition to investigate upstream effect on radial rotor. The results show that span-wise nonuniform total pressure distribution is generated and radial and circumferential Combined distortion is formed at centrifugal rotor inlet. The upstream stator wake deflects to rotor rotation direction and decreases with blade span increases. Circumferential distortion causes different separated flow formations at different pitch positions. The tip leakage vortex is suppressed in centrifugal blade passages. Under distorted inlet condition, flow direction of centrifugal impeller leading edge upstream varies evidently near hub and shroud but varies slightly at mid-span. In addition, Compressor stage inlet distortion produces remarkable effect on blade loading of centrifugal blade both along chordwise and pitchwise. © 2010 Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg.

Hakan Bagci - One of the best experts on this subject based on the ideXlab platform.

  • COMPRESSION AND RADIATION OF HIGH-POWER SHORT RF PULSES. II. A NOVEL ANTENNA ARRAY DESIGN WITH Combined Compressor/RADIATOR ELEMENTS
    Progress in Electromagnetics Research-pier, 2020
    Co-Authors: Kostyantyn Sirenko, V L Pazynin, Yuriy K Sirenko, Hakan Bagci
    Abstract:

    The paper discusses the radiation of compressed high power short RF pulses using two difierent types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a Compressor and a radiator. The studies on the monopole antenna demonstrate the possibility of a high power short RF pulse's e-cient radiation even using simple antennas. The studies on the novel array design demonstrate that a reduced size array with lower pulse distortion and power decay can be constructed by assembling the array from elements each of which integrates a Compressor and a radiator. This design idea can be used with any type of antenna array; in this work it is applied to a phased array.

  • compression and radiation of high power short rf pulses ii a novel antenna array design with Combined Compressor radiator elements
    Progress in Electromagnetics Research-pier, 2011
    Co-Authors: Kostyantyn Sirenko, V L Pazynin, Yuriy K Sirenko, Hakan Bagci
    Abstract:

    The paper discusses the radiation of compressed high power short RF pulses using two difierent types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a Compressor and a radiator. The studies on the monopole antenna demonstrate the possibility of a high power short RF pulse's e-cient radiation even using simple antennas. The studies on the novel array design demonstrate that a reduced size array with lower pulse distortion and power decay can be constructed by assembling the array from elements each of which integrates a Compressor and a radiator. This design idea can be used with any type of antenna array; in this work it is applied to a phased array.