跨声风扇转子的BVF气动优化方法

Aerodynamic optimization method of transonic fan rotor based on BVF

将加功量作为目标函数并结合边界涡量流BVF(Boundary Vorticity Flux)这个诊断因子,对某高性能跨声风扇转子进行了优化.通过基于局部动力学的BVF诊断可以捕捉到流场分离流动在叶片表面上的物理根源,可以清晰的显示出激波结构.尽管优化后加功量增大,但因为BVF分布改善,激波结构和分离流动被良好地控制.三维粘性N-S(Navier-Stokes)程序计算结果表明,风扇转子在近峰值效率工况下压比提高了7.69%,效率提高了1.92%,在全工况范围转子性能都得到了较大提升.基于BVF诊断的优化手段在风扇/压气机的优化中可起到很大的作用.

The aerodynamic optimization of a transonic fan rotor was implemented by controlling the BVF （ boundary vorticity flux） distribution on rotor blade. A novel objective function of torque associated with BVF was used to optimize the blade configuration. The physical sources of separated flow could be probed on rotor blade through the BVF diagnosis, which was a novel diagnosis method based on local dynamics. The shock structure was showed clearly on the rotor blade in this diagnosis method. Although the torque of the optimized rotor was increased, the shock strength was decreased and the separated flow was controlled better, as the BVF distribution was better than before. The results of 3D CFD（ computational fluid dynamics） analysis indicate that not only the total pressure ratio of rotor is increased by 7.69%, but also the adiabatic efficiency is increased by 1.92% too. The optimized rotor has a higher performance over a wide range of mass flow. The optimization method based on BVF can play an important role in the optimization design of fans/compressors.