NASA rotor 37 was used as a ’blind’ test case for turbomachinery CFD by the Turbimachinery Com-mittee of the IGTI. The rotor is a transonic compressor with a tip speed of 454 m/s (15OO ft/s) anda relatively high pre...NASA rotor 37 was used as a ’blind’ test case for turbomachinery CFD by the Turbimachinery Com-mittee of the IGTI. The rotor is a transonic compressor with a tip speed of 454 m/s (15OO ft/s) anda relatively high pressure ratio of 2.1. It was tested in isolation with a circumferentially uniform inletflow so that the flow through it should be steady apart from any effects of passage to passage geometry variation and mechanical vibration. As such it represents the simplest possible type of test forthree-dimensional turbomachinery flow solvers. However, the rotor still presents a real challenge to3D viscous flow solvers because the shock wave-boundary layer interaction is strong and the effects ofviscosity are dominant in determining the flow deviation and hence the pressure ratio. Eleven ’blind’solutions were submitted and in addition a ’non-blind’ solution was used to prepare for the exercise-This paper reviews the fiow in the test case and the comparisons of the CFD solutions with the testdata. Lessons for both the Flow Physics in transonic has and for the application of CFD to suchmachines are pointed out.展开更多
In a centrifugal compressor, the leakage flow through the tip clearance generates the tip leakage vortex by the in- teraction with the main flow, and consequently makes the flow in the impeller passage more complex by...In a centrifugal compressor, the leakage flow through the tip clearance generates the tip leakage vortex by the in- teraction with the main flow, and consequently makes the flow in the impeller passage more complex by the inte- raction with the passage vortex. In addition, the tip leakage vortex interacts with the shock wave on the suction surface near the blade tip in the transonic centrifugal compressor impeller. Therefore, the detailed examination for the influence of the tip leakage vortex becomes seriously important to improve the aerodynamic performance cs- pccia｜ly for the transonic centrifugal compressor. In this study, the flows in the transonic centrifugal compressor with and without the tip clearance at the design condition were analyzed numerically by using the commercial CFD code. The computed results revealed that the tip leakage vortex induced by the high loading at the blade tip around the leading edge affected the loss generation by the reduction or the suppression of the shock wave on the suction surface of the blade.展开更多
The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Cas...The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critical flow structures are studied through the analysis of the tip leakage mass and momentum transport that further re-veal the CGCT mechanism.展开更多
A throughflow model based on the time-marching finite volume approach is described in this paper. The governing equations are derived by circumferentially averaging the three-dimensional Navier-Stokes equations neglec...A throughflow model based on the time-marching finite volume approach is described in this paper. The governing equations are derived by circumferentially averaging the three-dimensional Navier-Stokes equations neglecting the circumferentially non-uniform and viscous terms. An inviscid blade force model similar to the Large-particle method is derived. The viscous blade force has been modeled by the distributed loss model. The convective fluxes of the governing equation are discretized with the Edward’s low-diffusion flux-splitting (LDFSS) scheme. And a point-iterative Symmetric Gauss-Seidel (SGS) scheme is used in the temporal discretization. The throughflow model has been applied to the NASA Rotor 67 and a high-load transonic fan stage ATS-2. The reasonable good agreements with the experiments and the 3D viscous computations show the potential of the method.展开更多
文摘NASA rotor 37 was used as a ’blind’ test case for turbomachinery CFD by the Turbimachinery Com-mittee of the IGTI. The rotor is a transonic compressor with a tip speed of 454 m/s (15OO ft/s) anda relatively high pressure ratio of 2.1. It was tested in isolation with a circumferentially uniform inletflow so that the flow through it should be steady apart from any effects of passage to passage geometry variation and mechanical vibration. As such it represents the simplest possible type of test forthree-dimensional turbomachinery flow solvers. However, the rotor still presents a real challenge to3D viscous flow solvers because the shock wave-boundary layer interaction is strong and the effects ofviscosity are dominant in determining the flow deviation and hence the pressure ratio. Eleven ’blind’solutions were submitted and in addition a ’non-blind’ solution was used to prepare for the exercise-This paper reviews the fiow in the test case and the comparisons of the CFD solutions with the testdata. Lessons for both the Flow Physics in transonic has and for the application of CFD to suchmachines are pointed out.
文摘In a centrifugal compressor, the leakage flow through the tip clearance generates the tip leakage vortex by the in- teraction with the main flow, and consequently makes the flow in the impeller passage more complex by the inte- raction with the passage vortex. In addition, the tip leakage vortex interacts with the shock wave on the suction surface near the blade tip in the transonic centrifugal compressor impeller. Therefore, the detailed examination for the influence of the tip leakage vortex becomes seriously important to improve the aerodynamic performance cs- pccia｜ly for the transonic centrifugal compressor. In this study, the flows in the transonic centrifugal compressor with and without the tip clearance at the design condition were analyzed numerically by using the commercial CFD code. The computed results revealed that the tip leakage vortex induced by the high loading at the blade tip around the leading edge affected the loss generation by the reduction or the suppression of the shock wave on the suction surface of the blade.
基金supported by the GEA USA Programthe National Natural Science Foundation of China (Grant No.10477012)
文摘The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critical flow structures are studied through the analysis of the tip leakage mass and momentum transport that further re-veal the CGCT mechanism.
基金supported by National Natural Science Foundation of China (50676004, 50736007)"Fan-Zhou" Youth Foundation (20100401)the Fun-damental Research Funds for the Central Universities (YWF-10-02-013)
文摘A throughflow model based on the time-marching finite volume approach is described in this paper. The governing equations are derived by circumferentially averaging the three-dimensional Navier-Stokes equations neglecting the circumferentially non-uniform and viscous terms. An inviscid blade force model similar to the Large-particle method is derived. The viscous blade force has been modeled by the distributed loss model. The convective fluxes of the governing equation are discretized with the Edward’s low-diffusion flux-splitting (LDFSS) scheme. And a point-iterative Symmetric Gauss-Seidel (SGS) scheme is used in the temporal discretization. The throughflow model has been applied to the NASA Rotor 67 and a high-load transonic fan stage ATS-2. The reasonable good agreements with the experiments and the 3D viscous computations show the potential of the method.
