【摘要】 采用商业软件以及立于转动带子上的圆柱体模拟上游动叶尾迹,数值研究了动叶尾迹对后继高负荷静叶栅流动特性的影响。计算结果表明,其上游动叶栅尾迹的流入是造成后继静叶栅流动非定常性的根源。相对定常计算结果,高负荷叶片的流动参数在尾迹的干扰下发生周期性脉动,叶中的脉动幅值高于两端,尾迹向吸力面附面层"注入"具有较高动量的流体,引发提前转捩,湍流耗散损失超过削弱流动分离趋势造成的损失降低,非定常情况下叶栅总压损失系数高于定常情况。更多还原

【Abstract】 To investigate the influence of the wake interference on the flow in subsequent static cascade with highly loaded blades,the circular cylinder,put on a rotating band,has been used to simulate the rotor wake of the front stage. Results indicate that the unsteady characteristics of the subsequent static cascade are caused by the inflow of the front-stage wake.Comparing with the steady condition,the wake interference causes the periodic fluctuation of flow parameters in the cascade with highly loaded blades and the fluctuation amplitude at mid-span is higher than endwalls. The injection of higher energy fluid by the wake into boundary layer of blade suction surface causes earlier transition at suction side. Yet the turbulent dissipation loss is greater than the loss reduction causedby weakening the flow separation trend. So the total pressure loss coefficient of cascade is higher on unsteady condition.更多还原