Computational Investigation of Unsteady Effect of AxialrnSpacing on the Performance in a Contra-rotating AxialrnCompressor

摘要

Unsteady numerical simulations are conducted to investigate thernunsteady effects of axial spacing on the performance of a contra-rotatingrnaxial compressor. The results show that the adiabatic efficiency decreasesrnwith increasing axial gaps, and the stage efficiency is dominant by rotor2.rnThe variation of aerodynamic force is different for the two rotors. Inrnaddition, the variation of the fluctuating phenomenon also shows therndifferent behavior for the two rotors as the axial spacing increased. Thernperturbation form in the tip region varies for different axial gaps. For thernaxial gap of 60% a spiral focus is generated, and the perturbation form turnsrnto be a star node at the axial spacing of 40%. The impact of the stable spiralrnfocus on the flow field results in the reduction of the efficiency for a largerrnaxial spacing.