Three dimensional viscous flow due to a squeezing porous slider

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.& COPY; 2022 Elsevier Masson SAS. All rights reserved.

Automated summary

This study investigates the three-dimensional viscous flow caused by the expansion or contraction of a porous slider. The fluid injection for levitating the slider is not constant but changes with time, depending on the slider's location. The unsteady equations of motion are transformed into similarity form using the Reynolds number and dilation parameter. Closed-form expressions are derived for the limiting case of a Reynolds number tending to zero, while numerical methods are used for other cases. The effects of the slider's up and down movement on the flow field, lift, and drag properties are analyzed. It is found that the expansion of the flat slider suppresses lift and drag, while contraction has the opposite effect, which is practically significant for reducing frictional resistance during slider operation.