孔型几何参数对孔型密封泄漏和鼓风加热特性影响研究

Investigation on the Effects of Hole Geometrical Parameters on Leakage and Windage Heating Characteristics of Hole-Pattern Seals

为明确孔型密封设计中关键几何参数孔深、孔径的选取准则,提出了基于动网格技术和节点位移扩散方程、孔型密封孔深连续变化时三维计算网格的生成方法以及基于三维定常Reynolds-Averaged Navier-Stokes(RANS)方程的孔型密封泄漏量和鼓风加热功率的数值计算方法。研究了孔型几何参数孔深、孔径对孔型密封泄漏特性、鼓风加热特性的影响规律,计算分析了7种孔径D=2,3.175,5,7,9,11,14mm、孔深H在0.5～15mm范围连续变化时孔型密封的泄漏量、鼓风加热功率和孔腔流场结构,并与实验结果进行了对比。结果表明:本文提出的网格生成和数值计算方法能够可靠预测孔型密封的泄漏特性,且具有计算速度快、工作量小的优点;孔型密封泄漏量在深径比AR在0.15～0.25范围内取得最小值,在0.7～0.9范围内取得最大值;鼓风加热功率随孔径的增大而增大,随孔深的增大而减小;孔型密封设计中在孔径为2～5mm范围内选取较小的孔径,在深径比为0.2～0.5范围内选取较大的孔深。

To provide a comprehensive selection criterion for the critical geometry parameters of hole depth and hole diameter in the design process of hole-pattern seals,a novel mesh generation method and a steady numerical approach were presented to solve the leakage flow rate and windage heating power for the hole-pattern seal with varying hole depth based on the mesh deformation technique,the displacement diffusion equations of mesh nodes,and steady RANS solutions.The influences of hole depth and hole diameter on the leakage performance and windage heating characteristics were numerically investigated.The leakage flow rate,windage heating power and cavity flow field were computed for the hole-pattern seal with continuously variable hole depth(H=0.5-15mm)at seven hole diameters(D=2,3.175,5,7,9,11,14mm).The present numerical methods were validated by comparisons with the experimental data of leakage flow rates at different hole depths and rotational speeds.The results show that thepresent mesh generation method and numerical approach have reasonable accuracy to predict the leakage flow rate at different hole depths and diameters,with quick solution speed and less computation.The hole-pattern seal possesses the minimum leakage flow rate at the depth-todiameter ratio(AR)of 0.15-0.25,and the maximum value at AR=0.7-0.9.The windage heating power increases with the hole depth,but decreases with the hole diameter.In the design process of hole-pattern seals,it is better to choose a smaller value for the hole diameter in the range diameter of 2-5mm,and choose a larger value for the hole depth in the range of AR=0.2-0.5.