轮缘密封整周模型流动与封严特性数值研究

本文通过求解SST湍流模型以及三维Unsteady Reynolds-Averaged Navier-Stokes(URANS)方程,研究了单级轴流透平轮缘密封整周模型的流动与封严特性。分析了不同冷气流量下的封严效率与压力波动的变化,并通过与仅保留静叶和仅保留动叶的简化模型比较,分析了动静叶对主流与盘腔内压力波动的影响。结果表明:盘腔内部封严效率存在周向波动但无明显周期性规律,主流与盘腔内的压力周向波动受动静叶的影响,存在明显的周期性规律,静叶下游压力波动周期数等于静叶数,动叶上游与盘腔内部压力波动周期数等于动叶数。

Numerical Investigations on the Flow and Sealing Effectiveness of a Turbine Rim Seal Model With Whole Cavity

This paper presents a numerical investigation on the sealing performance of single turbine rim seal model with a whole cavity under three different coolant flow rates.Three-dimensional unsteady Reynolds-Averaged Navier-Stokes(URANS)equations,coupled with a fully developed shear stress transport(SST)turbulent model from ANSYS-CFX,are utilized to investigate the sealing effectiveness and flow characteristics.The effects of the existence of vanes and blades on the pressure distribution in annulus and cavity are investigated by comparing with two simplified models.One simplified model includes vane passages and a cavity and the other includes blade passages and a cavity.The numerical results show that the sealing effectiveness distribution in the cavity shows circumferential fluctuation but no obvious periodic rule in whole cycle model.The pressure circumferential fluctuations in annulus and cavity are affected by both vanes and blades and have obvious periodic rule.The number of pressure fluctuation cycles at the downstream of vanes equals the number of vanes and that at the upstream of blades and in the cavity equals the number of blades.