三元叶片型面造型对离心压缩机叶轮 气动性能影响的数值研究
Numerical Research on Effect of 3-D Blade Surface Profiles on Aerodynamic Performance of Centrifugal Compressor Impellers

以某一离心压缩机中的任意曲面叶轮为研究对象,将其“直纹面化”以降低制造成本,同时研究发现,直纹面化处理后任意空间曲面三元叶轮的气动性能下降。为了提升直纹面叶轮的气动性能,通过设计8+1套改型设计方案、调整叶片型线控制点、改变叶片前缘及尾缘坐标,并借助流体计算软件Numeca进行了数值模拟,由此求得了性能曲线及内部流场。结果显示:当直纹面叶轮叶片进口安装角扩大时,气动性能明显下降,反之亦然;当直纹面叶轮叶片出口安装角扩大时,压比的提升较为明显,叶片出口安装角缩小时,效率的改善更为显著;综合改进叶片前缘与尾缘的型线,可使直纹面叶轮的气动性能显著提高。研究表明,直纹面叶轮气动性能对叶片型线变化非常敏感,通过适当地改进型线可以有效提升直纹面叶轮的气动性能,使之不低于原任意曲面叶轮的气动性能。
A centrifugal compressor impeller with arbitrary curved surface is analyzed. The surface is transformed into ruled surface for the purpose of reducing manufacture costs, however the transformation leads to a worse aerodynamic performance. To improve the performance of impeller with ruled surface, 8+1 sets of schemes are designed by changing control points of shape lines of leading edge and/or trailing edge, and the internal flow field and performance curves are evaluated by commercial CFD software Numeca. The aerodynamic performance worsens when the inlet blade angle increases and vice versa. The pressure ratio rises more considerably as the outlet blade angle increases, while the efficiency is improved more obviously as the outlet blade angle decreases. The integrated method combines the results from the changing of both leading and trailing edges to effectively enhance the aerodynamic performance. This approach indicates that the impeller with ruled surface is very sensitive to the modification of shape lines, and the aerodynamic performance of the appropriately modified impeller with ruled surface can be comparable with that of impeller with arbitrary curved surface