为较好地获知非接触密封动力学特性,提出了一种考虑倾斜的密封高阶非线性油膜力和动特性系数求解数学模型的扩展模型,该模型包括倾斜因素下的密封间隙流体油膜厚度方程、油膜瞬态压力求解方程;利用该模型可得到密封间隙内油膜对密封环的高阶油膜力表达方式,及高阶非线性项时的油膜力相对误差。通过算例分析,结果表明随着无量纲非线性稳态油膜力阶数的增加,油膜力计算相对误差越来越小;随着油膜厚度的增大,非线性稳态油膜力、非线性刚度系数和阻尼系数减小。
In order to obtain the dynamic characteristics of the unstable situation of the non-contact mechanical seal, we present a mathematical model for solving the higher order nonlinear oil film force and dynamic coefficients of the tilting non-contact mechanical seal. The model includes the fluid film thickness equation with the tilting seal ring and the equation for solving the transient film pressure considered. With the model, we establish the expression for the higher order nonlinear film force on the seal film gap, and we obtain the error of the higher order nonlinear film force relative to the linear film force. We give an example for calculating and verifying the nonlinear film force and the relative error for the tilting non-contact mechanical seal. The calculated results and their analysis show pre- liminarily that the relative error of the nonlinear film force decreases with increasing order, and all of the non-linear film forces, the non-linear stiffness coefficients and damping coefficients decrease with increasing film thickness.