Three dimensional viscous flow due to a squeezing porous slider

Abstract

Three dimensional viscous flow as a result of expanding or contracting porous slider is undertaken in the present analysis. The fluid injection to levitate the slider is not taken constant, but it changes with time in accordance with the location of the slider at any time. The unsteady equations of motion corresponding to the fluid flow between the slider and the ground are transformed into their similarity form with the help of two dimensionless parameters; Reynolds number and dilation parameter. In the limiting case of Reynolds number tending to zero, closed-form expressions are derived. Otherwise, the system of equations is treated numerically, and how the up and down movement of the porous slider contributes to the flow field as well as to the lift and drag properties are studied in detail. It is found that flat slider expansion leads to suppression of lift and drag, with an opposite impact of slider contraction. The former is of practical significance for encountering less frictional resistance while operating the slider.