二次空气系统中轴向旋转孔流阻特性的数值研究

通过计算流体动力学(CFD)研究了燃气轮机二次空气系统中轴向旋转孔的进口圆角比、长径比、压比和进口气流冲角对轴向旋转孔流量系数C_d的影响。计算结果表明,当孔的进口圆角比r/d0.2时,孔圆角的变化对流量系数影响显著;长径比、压比对进口有/无圆角的孔的流量系数影响规律不同,长径比越大时进口气流冲角对流量系数的影响越小;进口圆角比也会影响进口气流冲角对流量系数的影响规律。依据数值计算结果,对典型的旋转孔流量系数估算公式进行了修正,提高了经验公式的计算精度。

Numerical Study on Flow Resistance Characteristics of Axial Rotating Orifice in Secondary Air System

The influence of inlet fillet ratio,length-diameter ratio,pressure ratio and flow resistance characteristics of axial rotating orifice in gas turbine secondary air system are studied by CFD numerical method.The calculation results show that when the inlet fillet ratio r/d <0.2,the change of the fillet has a significant effect on the flow coefficient .The influence of length diameter ratio and pressure ratio on flow coefficient of the inlet with or without fillet is different.With the increase of orifice length,the discharge coefficient is less affected by incidence.The inlet fillet also affects the influence law of the inpact angle of inlet flow on the flow coefficient. Based on the numerical analysis results, the typical correlations for the discharge coefficient of axial rotating orifices be modified, significantly improve the accuracy of the correlations.