Enhancing stall margin has a great importance for the development of turbo compressors. The application of circumferential grooved casing treatment(CGCT) is a useful method of increasing the stable operating range of ...Enhancing stall margin has a great importance for the development of turbo compressors. The application of circumferential grooved casing treatment(CGCT) is a useful method of increasing the stable operating range of the compressor, and the effectiveness of this kind of casing treatment have been proved by numerous experiments. In this paper, a single circumferential casing groove is placed along the shroud side of the vaned diffuser. To clarify the effect of circumferential groove on the centrifugal compressor stability and corresponding flow mechanism, numerical investigations with different radial location, axial depth and radial width were carried out to compare the results. The computational fluid dynamics(CFD) analyses results show that the centrifugal compressor with a single circumferential groove in diffuser passage can extend stable operating range while the efficiency over the whole operating range decreases a little. Efforts were made to study blade level flow mechanisms to determine how the circumferential groove impacts the compressor's stall margin(SM) and performance. Some comparisons of the flow features with different parameter of grooved casing treatment are performed, and the results indicate that the low energy flow in the tip clearance is sucked into the groove and the area of the low energy fluid region shrinks, which helps to improve the stall margin of the centrifugal compressor. The numerical results showed that a combination of position,width and depth of circumferential groove will maximize stall margin improvement(SMI) of the centrifugal compressor.展开更多
基金National Natural Science Foundation of China(No.51776155)
文摘Enhancing stall margin has a great importance for the development of turbo compressors. The application of circumferential grooved casing treatment(CGCT) is a useful method of increasing the stable operating range of the compressor, and the effectiveness of this kind of casing treatment have been proved by numerous experiments. In this paper, a single circumferential casing groove is placed along the shroud side of the vaned diffuser. To clarify the effect of circumferential groove on the centrifugal compressor stability and corresponding flow mechanism, numerical investigations with different radial location, axial depth and radial width were carried out to compare the results. The computational fluid dynamics(CFD) analyses results show that the centrifugal compressor with a single circumferential groove in diffuser passage can extend stable operating range while the efficiency over the whole operating range decreases a little. Efforts were made to study blade level flow mechanisms to determine how the circumferential groove impacts the compressor's stall margin(SM) and performance. Some comparisons of the flow features with different parameter of grooved casing treatment are performed, and the results indicate that the low energy flow in the tip clearance is sucked into the groove and the area of the low energy fluid region shrinks, which helps to improve the stall margin of the centrifugal compressor. The numerical results showed that a combination of position,width and depth of circumferential groove will maximize stall margin improvement(SMI) of the centrifugal compressor.
