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为减小高负荷低压涡轮叶型损失,提高低压涡轮叶栅气动性能,采用数值模拟方法研究尾缘形状对高负荷前加载低压涡轮叶栅L2F气动性能的影响.对比尾缘偏斜、增加尾缘厚度和Gurney襟翼对叶栅能量损失和流动的影响.结果表明:3种尾缘形状都能增加气流折转角,在低雷诺数时减小能量损失,在高雷诺数时增加损失,但总体上尾缘偏斜提高气动性能的效果更好.雷诺数为20 000、湍流度为3%时,尾缘偏斜能够减小16.5%叶栅能量损失,增加3.3%气流折转角.3种尾缘形状都使主流发生偏转,加速了吸力面边界层流动,抑制了流动分离,有利于减小损失;但尾缘改型增强了尾缘后流动掺混,会增加损失.
In order to reduce the loss of high-pressure and low-pressure turbine blades and improve the aerodynamic performance of low-pressure turbine cascades, the numerical simulation was used to study the influence of the trailing edge shape on the aerodynamic performance of low-pressure turbine cascade L2F loaded before high loads. Edge thickness and the effect of Gurney flaps on the energy loss and flow of cascades were studied.The results show that all three trailing edge shapes can increase the turning angle of airflow and reduce the energy loss at low Reynolds number and increase the loss at high Reynolds number In general, the deflection of the trailing edge improves the aerodynamic performance better, and the Reynolds number is 20 000. When the turbulence degree is 3%, the trailing edge deflection can reduce the energy loss of the cascade and increase the turning angle of airflow by 3.3% The edge shapes all deflect the mainstream and accelerate the flow of the boundary layer on the suction side, which restrains the flow separation and helps to reduce the loss. However, the tail-edge modification enhances the flow mixing after the tail edge and increases the loss.