旋转诱导燃气入侵的数值模拟

Numerical simulation of rotationally-induced ingress through turbine rim seals

在航空发动机涡轮级中,动盘的旋转会导致主流高温燃气从盘缘封严侵入转静盘腔系统.通过计算流体动力学方法对轴向封严结构下旋转诱导燃气入侵进行了研究,得到了在不同封严冷气流量下盘腔压力和封严间隙处径向速度的变化规律.分别计算基于质量和基于浓度定义的封严效率分布,并得到了相应最小封严流量.在不同旋转雷诺数下,用压力参数法估算了最小封严流量,所得结果与公开发表的经验关系式计算得出的一致.

In the turbine stage of the aero-engines,the rotation of disk can cause high-temperature gas in annulus ingest into the rotor-stator system through rim seal.Computational fluid dynamics（CFD） was applied to study the so-called rotationally-induced（RI） ingress through an axial seal clearance.The variation of the cavity pressure and the radial velocity at the seal clearance with the sealing flow rate was investigated.The effectiveness distributions based on mass and concentration were computed respectively,and the minimum sealing flow rate required to seal the system was determined from the computed effectiveness data.Pressure criterion was also used to estimate the minimum sealing flow rate for different rotational Reynolds numbers,and the results accord with previously published experimental correlation.