Numerical simulation of surface roughness effects in laminar lubrication using the lattice-Boltzmann method

The effect of stuface texture and roughness oil shear and pressure forces in tribological applications in the lubrication regime is analyzed by means of lattice- Boltzina) 111 simlllations that take the geometry of real sla face elements into account. Topographic data oil representative staface structurcs are obtained with high spatial resolution with the application qf all optical interference technique. The three-dimensional velocit y field past these surfaces is computed.for laminarflow of Newtonian fluids in the continuum regime. Subsequently, pressure and shear flow.factors are obtained by evaluating the velocity field in accordance with the extended Reynolds equation of Patir and Cheng (1978, ASME J. Tribol., 100, pp. 12-17). The approach allows all efficient determination of the hvdrodynainic characteristics qfmicrostructured sui.-taces in lubrication. Especially, the influence of anisotropy of surface texture on the hydrodynamic load capacity andfiriction is determined. The numerical method used in the present work is verified,for a simplified model configuration, the flow past a channel with sinusoidal walls. The results obtained indicate that fall numerical simulations should be used to accurately and ef ficientl * v compute the characteristic properties offilm.flows past rough surfaces and may therefore contribute to a better understanding and prediction of tribological problems.