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国际流体力学研究期刊
ESCI SJR: 0.206 SNIP: 0.446 CiteScore™: 0.5

ISSN 打印: 2152-5102
ISSN 在线: 2152-5110

国际流体力学研究期刊

DOI: 10.1615/InterJFluidMechRes.v35.i6.50
pages 570-780

Steady and Unsteady Flow Investigations on the Effect of Different Number of Diffuser Vanes

Ning He
SPMP, Shanghai Port Machinary LTD, Shanghai, P.R. China

ABSTRACT

This paper presents a computational analysis of a high-speed centrifugal compressor stage where emphasis is focused on both the steady and unsteady flow investigations and on the effect of different number of diffuser vanes on the stage operating range. The simulations were carried out for a centrifugal stage with a backswept impeller and several diffusers with 11, 22 and 33 vanes. For the steady simulations, an averaging approach was used at the interface between the impeller and the diffuser. For the unsteady simulations, geometry scaling was used to deal with the problem of unequal pitch. As the number of diffuser vanes was increased, the pressure recovery coefficient in the semi-vaneless space at surge condition was found to reduce. Also, as the number of diffuser vanes was increased, the flow distortion became more pronounced in the vaneless and semi-vaneless space. It is proposed that this more distorted flow is harmful to the pressure recovery in the semi-vaneless space giving stages with more diffuser vanes narrower flow ranges. It was also found that the diffuser area ratio is not the dominant factor influencing the flow range when the number of diffuser vanes changes.