Viscoelastic liquid bearing modeling via lattice Boltzmann method

摘要

As the need for higher areal recording density in hard disk drives (HDDs) requires continuous reduction of the fly height in head-disk interface, the tribological issues become critical during operation. In viscoelastic liquid bearing (VLB) technology, thin liquid films instead of air bearing are used for lubrication. In this paper, we developed a computational tool based on lattice Boltzmann method (LBM), which is accurate, fast, robust, and highly parallelizable, for the accurate modeling of a non-Newtonian ultrathin liquid film undergoing extremely high shear rates. We adopted truncated power-law and the Bird-Carreau models to take into account the shear rate dependent viscosity via the relaxation time in our LBM scheme. After the feasibility study of the pressure driven microchannel, the pressure and flow fields under the model slider were calculated for different constitutive relationships. Together with the order of magnitude analyses, our LBM simulations, using a physically realistic viscoelastic constitutive equation, will provide accurate predictions on VLB drive used in HDDs.