跨音速级叶片可控涡设计分析与试验研究

Numerical and Experimental Investigations on Transonic blade design by Controlled Vortex method

对某涡轮末级,本文采用可控涡方法,通过数值计算与传统自由涡的设计研究对比显示:前者的总总效率较后者提高了0.5%,功率提高了1.18%;可控涡设计通过控制静叶出口气流角使气体质量流量在径向重新分布,从而控制涡轮反动度沿着叶高的斜率变小,根部横向压力梯度的减小减弱了端部的二次流损失,顶部反动度的减小可降低顶部间隙的泄露损失;对可控涡设计静叶片按缩比制成环形叶栅试验件在风洞试验平台上试验,通过对比数值计算和试验的出口截面马赫数、轴向速度、出口速度环量及各截面静压沿型线分布等,可知试验数据和数值计算结果吻合的很好,试验获得的总压损失系数略高于数值计算,试验还表明在3个不同出口马赫数下,总压损失系数随着试验出口马赫数的增大逐步降低。

For the last stage of turbine designed by controlled vortex method,numerical calculation showed that this design increases the total-total efficiency for 0. 5% compared to traditional free vortex design,and the power output increases by 1. 18%. Controlled vortex design makes the mass flow redistribute along radial direction by means of control flowangle,decreasing the control slope of reaction degree along blade height,and the decrease of lateral pressure gradient in hub weakens the secondary flow loss in the end. The decrease in reaction degree on tip can lower leakage loss of tip gap. The stationary blades designed by controlled vortex technology were manufactured according to the shrink ratio and tested in wind tunnel platform. The Mach number of outlet section,axial velocity,outlet velocity swirl and each section static pressure distribution along molded lines were compared between numerical calculation and experimental test. It showed that numerical calculation results agree well with the experimental data. Total pressure loss coefficient of experiment is slightly higher than numerical calculation. Additionally,the experimental data also indicated that the total pressure loss coefficient decreases with outlet Mach number for the three differentoutlet Mach numbers tested.