Squeeze Films Between Rotating Porous Rubber Surface and Stationary Impermeable Rigid Surface

作为粘弹性流体动力润滑(VEHL)问题，研究了具有透气表面的旋转圆柱形多孔橡胶块与具有不透(无)孔表面的静止刚性板之间的挤压膜现象。刚性板在垂直于其表面的方向上作正弦振动，并绕其轴线旋转。为了估计多孔表面的变形，为简单起见，将圆柱形多孔橡胶块划分为一组同心环。假设每个环只发生轴向变形且独立于相邻环，并且假定截面面积不随轴向变形而改变。然后，将每个环替换为由三个元素组成的弹簧仪表盘模型。挤压油膜压力是通过同时求解包含流体惯性项的运动方程、连续性方程、包含流体旋转引起的离心力的拉普拉斯方程来获得的。…较薄的多孔基质，以及多孔橡胶块变形的控制方程。通过对圆柱形多孔橡胶块在挤压和旋转运动下的挤压油膜压力、挤压油膜力和摩擦力矩的实验数据的测量，验证了数值分析的正确性。结果表明：(1)挤压油膜压力和力的峰值随着正弦振荡运动的频率和幅度的增加以及时间平均膜厚的减小而增大。在这一点上，计算结果与实测值吻合较好。(2)对于同时作用于多孔橡胶块的正弦振动和旋转运动，随着转速的增加，挤压油膜压力和力随时间的变化有向负值方向移动的趋势。然而，当多孔橡胶表面的变形变得明显时，转速对挤压油膜压力和力的负峰移动的定量影响很小。这些事实在计算和测量结果中都可以看出。(3)摩擦力矩与转速成正比增加，当挤压运动和旋转运动同时作用时，摩擦力矩随正弦运动的频率和幅度而变化。在这一点上，计算结果与测量结果定性地吻合。较少

Squeeze film phenomena between a rotating cylindrical porous rubber block with permeable surface and a stationary rigid plate with impermeable (nonporous) surface have been studied as a problem of viscoelastic hydrodynamic lubrication (VEHL). The rigid plate oscillates sinusoidally in the direction perpendicular to its surface and rotates about its axis. To estimate the porous surface deformation, the cylindrical porous rubber block is divided into, for simplicity, a set of concentric rings. Each ring is assumed to be deformed only axially and independently from the neighboring ones, and also the cross-sectional area is assumed not to change by the axial deformation. Then, the each ring is replaced with a spring-dashpot model made of three elements. The squeeze film pressures are obtained by simultaneously solving the equation of motion including the fluid inertia terms, the continuity equation, the Laplace equation including the centrifugal force caused by the rotation of the fluid wi … More thin the porous matrix, and the governing equation for the deformation of the porous rubber block. Experimental data on the squeeze film pressure, the squeeze film force and the frictional torque are measured with a cylindrical porous rubber block under the squeezing and rotating motion to verify the numerical analysis.The results are summarized as follows;(1) The peaks of the squeeze film pressure and force become large as the frequency and amplitude of sinusoidally oscillated motion increase and the time average film thickness decreases. On this point, the calculated results are in good agreement with the measured results.(2) For the sinusoidally oscillated motion and the rotational motion simultaneously applied to the porous rubber block, the variations of the squeeze film pressure and force with time have a tendency to shift to negative region as the rotational velocity increases. However, when the deformation of the porous rubber surface becomes noticeable, the quantitative effect of the rotational velocity on the shift of negative peaks of the squeeze film pressure and force is significantly small. These facts can be seen in both calculated and measured results.(3) The frictional torque increases in proportion to the rotational velocity, and for the squeezing and rotational motion simultaneously applied, the frictional torque varies with the frequency and amplitude of sinusoidal motion. On this point, the calculate results qualitatively agree with the measured results. Less