CFD study of leakage flows in shroud cavities of a compressor impeller

10th International Conference on Compressors and their Systems

Soldatova, K.^1

RandD Laboratory Gas Dynamics of Turbo Machines, Peter the Great St.Petersburg Polytechnic University, Polytechnical st. 29, St.Petersburg, Russia^1

关键词: Centrifugal compressor stage;    Compressor impeller;    Equilibrium equation;    Flow calculations;    Flow characters;    Leakage coefficient;    Pressure coefficients;    Radial circulations;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/232/1/012045/pdf
DOI  :  10.1088/1757-899X/232/1/012045

来源: IOP

【 摘 要 】

The flow character in a gap between shroud disc of an impeller and a stator surface (shroud cavity) influences disc friction loss, labyrinth seal loss (parasitic losses) and thrust force. Flow calculations inside the shroud cavity of a model of centrifugal compressor stage and its labyrinth seal in a range of flow rates and axial width and radial gap are presented. The results are presented in terms of non-dimensional coefficients of flow, disc friction and seal leakage losses coefficients and pressure coefficient. The distributions meridional and tangential flow velocities correspond to the continuity and equilibrium equations - flow radial circulation exists in wide cavity and is absent in narrow cavities. The radial pressure distributions as measured and calculated are not fully comparable. The possible reason is that CFD-calculated leakage coefficient is less than calculated by A.Stodola formula. The influence of a cavity width on the losses and the thrust force requires a balanced design.