摘要
针对静压干气密封气膜压力分布算法效率较低或收敛性较差等问题提出一种改进的有限差分算法,采用该有限差分法求解小孔节流式静压干气密封气膜的非线性雷诺方程;基于流量平衡原理,提出了变步长逐步逼近的迭代算法,使得有限差分算法的计算效率、稳定性和收敛性大大提高,并且保证有限差分法在小间隙气膜下的稳定性和收敛性.通过MATLAB数值软件编写求解静压干气密封气膜的压力分布程序.分析了干气密封的气膜厚度对气膜开启力以及气膜刚度的影响.结果表明,径向压力由节流孔向内径和外径方向呈近似抛物线状下降,压力最大值出现在节流孔处,为3.756MPa,最小值为0.212MPa;端面气膜开启力随气膜厚度的增大而减小;在一定的工况下,随着气膜厚度的增大气膜刚度逐渐减小.
A modified finite difference method was developed to improve the traditional method adopted to derive the pressure distribution of aerostatic gas seals film. The nonlinear dimensionless Reynolds equation of the orifice-compensated aerostatic gas seal film was solved by the modified method. Based on the principle of flow equilibrium,a new iterative algorithm,the variable step size successive approximation method was presented to adjust the pressure at the orifice in the iterative process and enhance the calculating efficiency and convergence performance of the finite difference algorithm. A general program was written by u- sing the numerical software Matlab to analyze the pressure distribution of the aerostatic journal bearing and the impact of gas film thickness on film opening force and gas film stiffness. The results show that the radial pressure curve from the orifice to the inner and outer diameters was close to a parabola, with the maxi- mum pressure of 3. 756 MPa at the orifice and the minimum of 0. 212 MPa,and the end face gas film open ing force decreased with the increase of gas film thickness.
出处
《甘肃科学学报》
2014年第4期119-122,共4页
Journal of Gansu Sciences
关键词
静压干气密封
有限差分法
雷诺方程
变步长
气膜刚度
Aerostatic gas seal
Finite difference method
Reynolds equation
Variable step size
Gas film stiffness