Dynamics of liquid meniscus bridge of a vibrating disk: consideration of flow rheology

A modified Reynolds equation, which includes the effect of flow rheology, is derived to describe the flow behaviour of lubricant between the space of a magnetic head slider and a disk. Under the assumptions of a small vibration of the spacing, and zero contact angle of the liquid-solid interface, the dynamics of a liquid meniscus disk of finite radius is analysed. The time-dependent modified Reynolds equation is linearised, and solved, under the boundary condition considering Laplace pressure. The results show that the pressure and load carrying capacity consist of three terms, that is, the static meniscus force term, the spring term by the dynamic Laplace pressure, and time-dependent damping term by the flow rheology of the fluid. The flow rheology affects the static meniscus forces and the damping forces significantly as compared to the spring forces. The effects of flow rheology on the load carrying capacity are also discussed.