Axial Clearance

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Wei Lin Zhuge - One of the best experts on this subject based on the ideXlab platform.

  • unsteady leakage flow through Axial Clearance of an orc scroll expander
    Energy Procedia, 2017
    Co-Authors: Panpan Song, Wei Lin Zhuge, Yangjun Zhang, Lei Zhang, Hao Duan
    Abstract:

    Abstract As the scroll-type expander (STE) becomes an attractive expansion device for small-scale organic Rankine systems, performance enhancement of STE could achieve a further improvement of the energy efficiency of ORC system. The gas leakages through the Axial and radial Clearances have a great effect on the overall performance of STE. The present work proposed a three-dimensional numerical technique available for modeling the radial leakage flows through the Axial Clearances at the tip and root of scroll wrap. The radial leakage flow patterns of both Axial Clearances are investigated. Asymmetrical distribution of the radial leakage flow through the Axial Clearances at both sides of working chambers are revealed. Leakage flow difference between the top and bottom Axial leakage Clearances is comparatively discussed. The effects of radial leakage on the flow fields in the working chambers are also analyzed. The results show the radial leakage flows occur at the Axial Clearances of both the scroll segments between asymmetrical working chambers and those between symmetrical working chambers. Radial leakage flows through the top and bottom Axial Clearances are approximately symmetrical about the meshing line. Pressure distribution in the Axial Clearance passage is uneven along the scroll involute direction, especially in the Axial Clearance passages between asymmetric chambers. Pressure distortion occurs in the downstream of the Axial Clearance passage between asymmetric working chambers nearby the mesh point of the scroll wraps. Radial leakage flow leads to the secondary vortex flows and non-uniform pressure distributions in the working chambers.

  • Research on the effect of centrifugal compressor blade tip Clearance distribution on combustion engine turbocharger performance
    Hangkong Dongli Xuebao Journal of Aerospace Power, 2010
    Co-Authors: G.-d. Guo, Xin Qian Zheng, J. Z. Xu, Y.j. Zhang, Wei Lin Zhuge
    Abstract:

    Based on three-dimensional computational fluid dynamics method, the flow fields of two opposite impeller blade tip Clearance distribution compressor stages with vaneless diffuser were analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance were researched. This proves that non-uniform chord direction blade tip Clearance distribution impellers have wider operating range. The pressure ratio and efficiency of compressor stage whose outlet Axial Clearance height is smaller than inlet radial Clearance height are higher than that of compressor stage whose outlet Axial Clearance height is larger than inlet radial Clearance height. The smaller outlet Axial Clearance height weakens the Clearance flow in aft half of impeller passage, improves the impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller outlet Axial Clearance height gets higher efficiency since it reduces impeller aft blade tip Clearance leakage vortices intensity and makes the vortices breakdown and dissipation loss less in impeller passage and vaneless diffuser passage.

  • Research on Transonic Centrifugal Compressor Blades Tip Clearance Distribution of Vehicle Turbocharger
    SAE International Journal of Fuels and Lubricants, 2008
    Co-Authors: Yangjun Zhang, Xin Qian Zheng, Wei Lin Zhuge, Jianzhong Xu
    Abstract:

    ABSTRACT Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control.

  • Research on transonic centrifugal compressor blades tip Clearance distribution of vehicle turbocharger
    SAE Technical Papers, 2008
    Co-Authors: Gongda Guo, Xin Qian Zheng, Wei Lin Zhuge, Yangjun Zhang, Jianzhong Xu
    Abstract:

    Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control. © 2008 SAE International.

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

  • unsteady leakage flow through Axial Clearance of an orc scroll expander
    Energy Procedia, 2017
    Co-Authors: Panpan Song, Wei Lin Zhuge, Yangjun Zhang, Lei Zhang, Hao Duan
    Abstract:

    Abstract As the scroll-type expander (STE) becomes an attractive expansion device for small-scale organic Rankine systems, performance enhancement of STE could achieve a further improvement of the energy efficiency of ORC system. The gas leakages through the Axial and radial Clearances have a great effect on the overall performance of STE. The present work proposed a three-dimensional numerical technique available for modeling the radial leakage flows through the Axial Clearances at the tip and root of scroll wrap. The radial leakage flow patterns of both Axial Clearances are investigated. Asymmetrical distribution of the radial leakage flow through the Axial Clearances at both sides of working chambers are revealed. Leakage flow difference between the top and bottom Axial leakage Clearances is comparatively discussed. The effects of radial leakage on the flow fields in the working chambers are also analyzed. The results show the radial leakage flows occur at the Axial Clearances of both the scroll segments between asymmetrical working chambers and those between symmetrical working chambers. Radial leakage flows through the top and bottom Axial Clearances are approximately symmetrical about the meshing line. Pressure distribution in the Axial Clearance passage is uneven along the scroll involute direction, especially in the Axial Clearance passages between asymmetric chambers. Pressure distortion occurs in the downstream of the Axial Clearance passage between asymmetric working chambers nearby the mesh point of the scroll wraps. Radial leakage flow leads to the secondary vortex flows and non-uniform pressure distributions in the working chambers.

  • Research on Transonic Centrifugal Compressor Blades Tip Clearance Distribution of Vehicle Turbocharger
    SAE International Journal of Fuels and Lubricants, 2008
    Co-Authors: Yangjun Zhang, Xin Qian Zheng, Wei Lin Zhuge, Jianzhong Xu
    Abstract:

    ABSTRACT Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control.

  • Research on transonic centrifugal compressor blades tip Clearance distribution of vehicle turbocharger
    SAE Technical Papers, 2008
    Co-Authors: Gongda Guo, Xin Qian Zheng, Wei Lin Zhuge, Yangjun Zhang, Jianzhong Xu
    Abstract:

    Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control. © 2008 SAE International.

Jianzhong Xu - One of the best experts on this subject based on the ideXlab platform.

  • Research on Transonic Centrifugal Compressor Blades Tip Clearance Distribution of Vehicle Turbocharger
    SAE International Journal of Fuels and Lubricants, 2008
    Co-Authors: Yangjun Zhang, Xin Qian Zheng, Wei Lin Zhuge, Jianzhong Xu
    Abstract:

    ABSTRACT Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control.

  • Research on transonic centrifugal compressor blades tip Clearance distribution of vehicle turbocharger
    SAE Technical Papers, 2008
    Co-Authors: Gongda Guo, Xin Qian Zheng, Wei Lin Zhuge, Yangjun Zhang, Jianzhong Xu
    Abstract:

    Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control. © 2008 SAE International.

Paul E. Allaire - One of the best experts on this subject based on the ideXlab platform.

  • Model Validation for an Active Magnetic Bearing Based Compressor Surge Control Test Rig
    Journal of Vibration and Acoustics, 2010
    Co-Authors: Young Yoon, Christopher Goyne, Paul E. Allaire
    Abstract:

    In this paper, we present experimental test data for the validation of a recently introduced mathematical model for centrifugal compression systems with variable impeller Axial Clearances. Employing the active magnetic bearings (AMBs) of a compressor built for the experimental study of surge, the Axial Clearance between the impeller and the static shroud is servo controlled, and the measured variations in the compressor output flow are compared with the mathematical model. The steady state and the dynamic responses of the compression system induced by varying the impeller tip Clearance are measured and compared with the theoretical predictions, and the states of the compression system in surge condition are collected and analyzed. Parameters in the compression system model, such as the Greitzer parameter B and Helmholtz frequency ω H are experimentally identified. Also, the servo dynamics of the magnetic bearing that controls the Axial impeller position is determined experimentally. To further validate the mathematical model and the feasibility of using the impeller tip Clearance for controlling surge, we present a design example for an active surge controller based on the derived model, and simulate the response of the compression system. This design exercise also helps us understand the possible challenges that one could face in the design and implementation of a successful surge controller.

  • Model Validation for an Active Magnetic Bearing Based Compressor Surge Control Test Rig
    Journal of Vibration and Acoustics, 2010
    Co-Authors: Se-young Yoon, Christopher Goyne, Kin Tien Lim, Zongli Lin, Paul E. Allaire
    Abstract:

    Inthis paper, we present experimental test data for the validationof a recently introduced mathematical model for centrifugal compression systemswith variable impeller Axial Clearances. Employing the active magnetic bearings(AMBs) of a compressor built for the experimental study ofsurge, the Axial Clearance between the impeller and the staticshroud is servo controlled, and the measured variations in thecompressor output flow are compared with the mathematical model. Thesteady state and the dynamic responses of the compression systeminduced by varying the impeller tip Clearance are measured andcompared with the theoretical predictions, and the states of thecompression system in surge condition are collected and analyzed. Parametersin the compression system model, such as the Greitzer parameterB and Helmholtz frequency H are experimentally identified. Also, theservo dynamics of the magnetic bearing that controls the Axialimpeller position is determined experimentally. To further validate the mathematicalmodel and the feasibility of using the impeller tip Clearancefor controlling surge, we present a design example for anactive surge controller based on the derived model, and simulatethe response of the compression system. This design exercise alsohelps us understand the possible challenges that one could facein the design and implementation of a successful surge controller. \n\t\t\n\t\t\t ©2010 American Society of Mechanical Engineers

Xin Qian Zheng - One of the best experts on this subject based on the ideXlab platform.

  • Research on the effect of centrifugal compressor blade tip Clearance distribution on combustion engine turbocharger performance
    Hangkong Dongli Xuebao Journal of Aerospace Power, 2010
    Co-Authors: G.-d. Guo, Xin Qian Zheng, J. Z. Xu, Y.j. Zhang, Wei Lin Zhuge
    Abstract:

    Based on three-dimensional computational fluid dynamics method, the flow fields of two opposite impeller blade tip Clearance distribution compressor stages with vaneless diffuser were analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance were researched. This proves that non-uniform chord direction blade tip Clearance distribution impellers have wider operating range. The pressure ratio and efficiency of compressor stage whose outlet Axial Clearance height is smaller than inlet radial Clearance height are higher than that of compressor stage whose outlet Axial Clearance height is larger than inlet radial Clearance height. The smaller outlet Axial Clearance height weakens the Clearance flow in aft half of impeller passage, improves the impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller outlet Axial Clearance height gets higher efficiency since it reduces impeller aft blade tip Clearance leakage vortices intensity and makes the vortices breakdown and dissipation loss less in impeller passage and vaneless diffuser passage.

  • Research on Transonic Centrifugal Compressor Blades Tip Clearance Distribution of Vehicle Turbocharger
    SAE International Journal of Fuels and Lubricants, 2008
    Co-Authors: Yangjun Zhang, Xin Qian Zheng, Wei Lin Zhuge, Jianzhong Xu
    Abstract:

    ABSTRACT Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control.

  • Research on transonic centrifugal compressor blades tip Clearance distribution of vehicle turbocharger
    SAE Technical Papers, 2008
    Co-Authors: Gongda Guo, Xin Qian Zheng, Wei Lin Zhuge, Yangjun Zhang, Jianzhong Xu
    Abstract:

    Flow induced by blades tip Clearance is important for centrifugal compressor, especially for the high charging ratio transonic centrifugal compressor of vehicle. Based on three-dimensional CFD method, the flow fields of two opposite impeller blades tip Clearance distribution compressor stages with vaneless diffuser are analyzed. The law and action mechanism of tip Clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance are researched. It is verified that the pressure ratio and efficiency of compressor stage whose aft Axial Clearance height is smaller than fore radial Clearance height is higher than that of compressor stage whose aft Axial Clearance height is larger than fore radial Clearance height. The smaller aft Axial Clearance height weakens the flow in aft half of impeller passage, improves impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller aft Axial Clearance height gets higher efficiency because it reduces impeller aft blades tip Clearance leakage vortices intensity and imposes the vortices breakdown and dissipation loss less in impeller passage exit and vaneless diffuser passage. The research of the impeller blades tip Clearance distribution effect on vehicle transonic centrifugal compressor performance and flow structure lays a foundation for transonic centrifugal compressor flow control. © 2008 SAE International.