基于二维厚板模型的波箔片轴承静特性

Static characterization of bump-type gas foil bearing:intergration of top foil 2-D thick plate model

建立平箔片的二维厚板有限元模型,运用有限单元法和有限差分法耦合求解Reynolds方程和气膜厚度方程,研究了在两个工作转速下气体波箔片轴承在中截面和边缘处最小气膜厚度随轴承承载力变化规律.通过数值仿真对该模型、一维梁模型、二维薄壳模型和文献实验数据进行对比分析,结果表明:在轴承中截面处,3个模型的最小气膜厚度仿真结果都与实验结果符合得很好,但在轴承边缘处,由于二维厚板模型考虑了平箔片的剪切效应,因此其最小气膜厚度比二维薄壳模型的结果更接近实验值,而一维梁模型只考虑轴承圆周方向,因此不能体现气膜厚度沿轴承长度方向的变化规律.通过研究,为分析箔片轴承动力学特性奠定了理论基础.

The 2-D （two-dimensional） thick plate finite element model for top foil was developed. By using coupled finite element mothod and finite difference method, the com- pressible gas lubricated Reynolds equation and the film thickness equation were solved cou- pling together. Predictions of minimum gas film thickness for increasing static loads at two speeds were obtained for bearing mid-plane and edge of bump-type gas foil bearing. The nu- merical results of this finite element model were compared with 1-D （one-dimensional） beam model model, 2-D shin shell model and test data. The results indicate that the minimum film thickness of three models agree well with test data at bearing min-plane, but at bearing edge, the accuracy of 2-D thick plate model is the highest due to its shear effect. 1-D beam model can not reflect film thickness variation along the bearing length direction because it on- ly considers the circumferential direction. The study in this paper established the theoretical foundation of dynamic characteristics research of bump-type gas foil bearing.