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为了研究时序效应对尾迹传递过程的影响,利用基于密度修正的求解雷诺平均N-S方程的商用CFD软件对某一1.5级轴流低压涡轮级进行了详细数值模拟。通过调整第二级导叶的周向位置来产生时序效应,结合涡轮级中湍动能分布、叶片表面剪切应力分布等来详细分析时序效应对涡轮流场的影响。结果表明:同名叶栅数量比例是影响时序效应的一个重要因素,文中时序效应对涡轮效率影响很小,涡轮最大和最小气动效率之间相差0.1%。时序效应对涡轮性能的影响主要体现在尾迹与主流之间的掺混损失和尾迹诱导的边界层转涙损失两方面。当一条进口导叶尾迹在靠近出口导叶吸力面流过通道而与其相邻的另一条尾迹通过出口导叶压力面附近时,涡轮效率最大;当一条进口导叶尾迹撞击在出口导叶前缘而另一条尾迹从出口导叶通道中部通过时涡轮效率最小。
In order to study the effect of timing effect on the wake transfer process, a 1.5-level axial-flow low-pressure turbine stage was numerically simulated in detail using commercial CFD software based on density correction to solve the Reynolds-averaged N-S equation. The effect of timing effect on turbine flow field is analyzed in detail by adjusting the circumferential position of the second-stage guide vane to generate timing effects and combining the distribution of turbulent kinetic energy in the turbine stage and the shear stress distribution on the blade surface. The results show that the ratio of cascades with the same name is an important factor affecting the timing effect. The timing effect has little effect on the turbine efficiency and the difference between the maximum and the minimum aerodynamic efficiency of the turbine is 0.1%. The effect of timing effect on turbine performance is mainly reflected in the blend loss between the wake and the mainstream and the wake transfer induced by the wake. Turbine efficiency is maximized when one inlet guide vane traverses the passage near the suction side of the outlet guide vane and another adjacent wake of the guide vane passes through the exit guide vane pressure surface. When one inlet guide vane hits the leading edge of the exit vane Turbine efficiency is minimized when the other wake passes through the middle of the exit guide vane passageway.