Pulsating Flow of a Viscous Fluid over a Cavity Containing a Compressible Gas Bubble

A two-dimensional pulsating flow of a viscous fluid in plane channel whose wall has rectangular microcavities partially or completely filled with compressible gas is investigated. This problem formulation can clarify the friction reduction mechanism laminar sublayer turbulent boundary layer over textured stripped superhydrophobic surface containing periodically arranged micro-cavities gas. It assumed that dimensions cavities are much smaller than thickness. On macroscale, one-dimensional unsteady no-slip conditions on walls and harmonic variation pressure difference solved. The solution obtained this way used for formulating non-stationary time periodic space scale chosen cavity (microscale), instantaneous volume bubble depending cavity. microscale near occurs Stokes regime. numerical using an original version element method. parametric study field shear performed. averaged parameters characterizing effective ‘velocity slip’ calculated.