Abstract In this study, a transient mixed lubrication model that considers mass-conserving cavitation and deterministic asperity contacts is established to study the evolution of the tribological behavior of spiral-groove thrust bearings during start-up. To overcome oil film thickness discontinuity at the edges and the complicated boundary shape of spiral grooves, a boundary-fitted coordinate system transformation is adopted. The evolution of the tribological behavior, including the asperity contact force, load-carrying capacity, minimum oil film thickness, and friction torque during start-up, is presented using the current model. To illustrate more clearly, the evolution of hydrodynamic pressure and cavitation fraction is also displayed. Experiments are performed to verify the proposed theoretical model. The results demonstrate that this model is able to capture the evolution of the tribological behavior of spiral-groove thrust bearings during start-up. To improve start-up performance, a parametric analysis is conducted to identify the effects of the main design parameters (groove depth, groove width ratio, and spiral angle) on the lift-off speed.

中文翻译：

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螺旋槽推力轴承启动时瞬态行为的理论与试验研究

摘要 在本研究中，建立了考虑质量守恒空化和确定性粗糙接触的瞬态混合润滑模型，以研究螺旋槽推力轴承在启动过程中摩擦学行为的演变。为了克服边缘油膜厚度不连续和螺旋槽边界形状复杂的问题，采用边界拟合坐标系变换。摩擦学行为的演变，包括粗糙接触力、承载能力、最小油膜厚度和启动期间的摩擦扭矩，使用当前模型呈现。为了更清楚地说明，还显示了流体动压和空化分数的演变。进行实验以验证所提出的理论模型。结果表明，该模型能够捕捉启动期间螺旋槽推力轴承摩擦学行为的演变。为了提高启动性能，进行了参数分析以确定主要设计参数（槽深、槽宽比和螺旋角）对提离速度的影响。