关键词: 压气机;前弯叶型;表面粗糙度;雷诺数;攻角;喷砂

Abstract: In order to study the impact of the surface roughness on the blade performance, the experiment on forward-skewed compressor blade was carried out with different Reynold numbers and angles of attack. The different surface roughness blades （Ra=3.0,6.2,12.3） resulted from wire-electrode cutting and sand blasting,while the blade geometry was guaranteed. The results showed that the laminar separation bubble is removed due to the transition of laminar flow in advance by increasing surface roughness. For low Reynolds number（Re=9×10⁵）, the surface Mach number distribution of Ra=3.0,6.2 are similar while the peak of isentropic Mach number distribution at the suction side decreases at Ra=12.3,and the difference becomes larger because of increasing surface roughness as the Reynolds number increases, but the overall performance keeps stable at occlusion attack angle i=-6.4° with Ra≥6.2. On the other hand, the viscosity loss on pressure side would decrease with the increasing surface roughness, which is opposite on the suction side and wake mixing loss. For low Reynolds number (Re=9×10⁵), the overall total pressure loss first ascends and then descends with the adding of the surface roughness, and for high Reynolds number (Re≥1.08×10⁶), i=2.6°~-2.4°,the total pressure loss ascends all the time, even inducing serious turbulent boundary layer separation. Furthermore, the Mach number distribution of the leading edge(before 20% chord length) on the suction side would not change with the adding of the roughness.

Key words: Compressor;Forward-skewed blade;Surface roughness;Reynolds number;Angle of attack;Sand blasting