Influence of the spanwise grooves on aerodynamic characteristics of the compressor cascade and rotor under different reynolds numbers

Abstract

In order to study the influence of the suction surface spanwise grooves under different Reynolds numbers (Re) on the loss characteristics of highly loaded compressor cascade and rotor. In the present study, numerical simulations were conducted to investigate the effects of the number and position of the suction surface spanwise groove on aerodynamic performance of the cascade with the final aim to extend the findings to a highly loaded transonic compressor rotor. Besides, the influence mechanism for the performance change of compressor cascade and rotor by spanwise groove at different Re was clarified. The combination 1-2-3-4-gro was selected as an optimal structure in accordance with the data weighting criterion. The investigation illustrates that, at high Re operating conditions, the spanwise grooves force the transition of boundary layer from laminar to turbulent, which causes a large turbulent boundary layer loss and increases the overall loss. But at low Re operating conditions, the laminar separation bubble is suppressed by spanwise grooves and the aerodynamic performance is improved. At Re = $1.3\times {10}^5$ , the total pressure loss can be reduced by 4.63% at the angle of attack of 0°. When this group scheme was applied to the highly loaded axial compressor transonic rotor, the stability margin of the rotor can be increased by 5.62% at Re = $7.7\times {10}^4$ condition. Moreover, at 20 km height condition, with the increase of rotating speed, the influence of 1-2-3-4-gro groove group on rotor stability margin is not great, but its efficiency improvement effect is gradually enhanced, which shows that 1-2-3-4-gro can effectively reduce rotor flow loss and increase its aerodynamic performance within this Re range.