汽轮机末级三维非定常流动数值模拟

采用三维粘性非定常数值模拟方法,对某汽轮机设计状态末级非定常流动进行了模拟,并对设计状态下各因素引起末级动叶表面产生非定常力的大小和作用机理进行了分析.结果表明,本文中的汽轮机末级在设计条件下,上游静叶尾缘激波和位势场对下游转子的影响比尾迹作用的影响更大,静叶尾缘激波和位势场导致下游转子叶片表面非定常力大小呈周期性变化;此外上游静子尾迹以及动叶尾缘出口膨胀波等也是产生转子叶片表面非定常力的因素.

Numerical Simulation of the 3-D Unsteady Flow in the Steam Turbine Last Stage

The unsteady flow of the steam turbine at design state was studied by the method of numerical simulation of 3-D viscous flow,and the analyses of unsteady force on the blade surface and the mechanism of action were carried out.The result indicates that at typical design operating conditions in the last stage of the steam turbine investigated here,shock and potential field interaction from upstream blade row is an order of magnitude greater than wake interaction.The shock and potential field interaction effects cause a periodic increase in the strength of the unsteady force acting on the downstream rotor blade surface.In addition,the wake interaction of upstream blade row and the expansion wave at rotor exit also cause an unsteady force acting on the downstream rotor blade surface.