【摘要】 采用预处理方法数值研究了低雷诺数时某小型燃气轮机透平叶栅间隙泄漏流动和气动性能.对比分析了雷诺数从4.40×104到2.55×105变化时,带间隙和不带间隙时流场的变化特性,研究了雷诺数对间隙泄漏流的影响,并和相应的实验结果及Denton预测值进行了对比.结果表明:对于间隙存在造成的流动损失,数值模拟结果与实验结果及Denton的预测值都十分接近,基本上不随着雷诺数的变化而变化;但是,随着雷诺数的减小,通道涡增强;间隙泄漏涡在和通道涡的相互作用中,强度减弱,在叶栅出口处的位置更加靠近中叶展;出口处的总压损失和气流角的分布也由于间隙泄漏涡强度和位置的变化而发生改变.更多还原

【Abstract】 The flow field of a small gas turbine cascade was numerically simulated with the preconditioning method at low Reynolds number varying from 4.40×104 to 2.55×105.Both the cases with and without tip clearance were considered in the simulation.The numerical results of the loss caused by the tip clearance agree well with the experimental data and the values predicted by the Denton formula.It is indicated that this loss will not change with the increase of the Reynolds number but the intensity of the passage vortex increases with the decrease of the Reynolds number.The tip leakage flow will weaken with the increase of the passage vortex because of the interaction between the passage vortex and the tip leakage vortex,and the position of the tip leakage vortex is more close to the middle of the passage.In addition,the distributions of the total pressure loss and the flow angle at the exit of the cascade are influenced by the intensity and the position of the tip leakage vortex.更多还原