容腔泄漏流对环形扩压叶栅性能的影响

Influence of cavity leakage flow on the performance of annular diffuser cascade

为探究容腔泄漏流对环形扩压叶栅气动性能及流场结构的影响,基于验证的数值模拟方法对环形扩压叶栅进行研究,分析泄漏流流量、周向速度大小对角区分离和总压损失的影响。结果表明,随着泄漏流量增加,通道涡PV扩展范围变大,角区分离提前出现,叶栅总压损失系数逐渐增加,当泄漏流量系数增大至1.5%时,总压损失系数增加22.9%;泄漏流周向速度的增加改善了近端壁区域堵塞情况,贴近端壁的流体向吸力面偏转程度减弱,偏移范围减小,当周向速度系数增大至1.1时,总压损失系数降低21.3%。

In order to explore the influence of cavity leakage flow on the aerodynamic performance and flow field structure of the annular diffuser cascade,the annular diffuser cascade was studied based on the verified numerical simulation method,and the effects of leakage flow rate and circumferential velocity on corner separation and total pressure loss were ana⁃lyzed.Results show that as the leakage flow increases,the expansion range of the passage vortex(PV)becomes larger,the corner separation occurs earlier,and the total pressure loss coefficient of the blade gradually increases.When the leakage flow coefficient increases to 1.5%,the total pressure loss coefficient expands by 22.9%.The increase in circumferential velocity of the leakage flow improves the blockage situation in the near end wall area.The degree of deviation of the fluid close to the end wall towards the suction surface is weakened,and the range of deviation is reduced.When the circumferential velocity coefficient increases to 1.1,the total pressure loss coefficient decreases by 21.3%.