蜂窝面迷宫密封泄漏特性和鼓风加热特性研究

Investigations on Leakage Characteristics and Windage Heating of Honeycomb Labyrinth Seal

基于标准k-ε紊流模型和三维Reynolds-Averaged Navier-Stokes方程求解方法,采用商用CFD软件ANSYS CFX数值研究了转子轴向偏移和径向伸长对典型航空发动机蜂窝面迷宫密封泄漏特性和鼓风加热特性的影响。计算了2种流量,3种转速下蜂窝面迷宫密封的鼓风加热系数和腔室旋流强度,并与实验结果进行了比较,验证了数值方法的准确性。分析了蜂窝面迷宫密封在4种转速、4种转子轴向偏移量和4种径向伸长量下的泄漏特性、鼓风加热特性和腔室旋流发展。研究结果表明:转子轴向偏移对密封泄漏量影响很小,可忽略;转子径向伸长使密封泄漏量显著减小;转子轴向偏移和径向伸长均引发密封鼓风加热系数的显著增大,降低冷却空气的冷却效果;转子轴向偏移和径向伸长均能显著改变密封腔室内的流场结构,增大密封腔室旋流速度。

The influences of the rotor axial offset and radial growth on the leakage performance and windage heating of honeycomb labyrinth seal used in a typical aero engine were numerically investigated based on the Reynolds-Averaged Navier-Stokes(RANS) equations and standard k — εturbulent model using commercial CFD software ANSYS CFX.The windage heating coefficient and swirl ratio of the honeycomb labyrinth seal were conducted at two flow rates and three rotational speeds.The accuracy of the present numerical approach was demonstrated by comparison of the experiment data numerical results.The leakage performance,windage heating characteristic and swirl development of the honeycomb labyrinth seal at four rotational speeds,four axial offset distances and four radial growths were analyzed.Numerical results show that the effect of rotor axial offset on the leakage flow rate is so small that can be ignored;Rotor radial growth results in a obvious decrease in the leakage flow rate;A significant increase is observed in the windage heating coefficient due to the rotor axial offset and radial growth,which results in a decrease in the cooling performance of cooling air;Rotor axial offset and radial growth both significantly influence the flow pattern in seal chamber and cause the swirl velocity increasing.