THE INSTABILITY OF SLIPPING FLOW IN A CURVILINEAR POROUS MICROCHANNEL

Abstract

The hydrodynamic instability of flow with slippage in a curvilinear porous microchannel between two stationary concentric cylinders is investigated. Unperturbed velocity profiles for a flow with slip are obtained. The problem of linear instability is solved numerically, using the collocation method. Calculations showed that an increase in the coefficient of slippage, the porosity of the medium and the width of the channel leads to an increase in the occupancy of the velocity profile of the undisturbed flow (the profile becomes more flat). This, in turn, leads to an increase in the critical values of Dean number and the critical wave length of the perturbation, which determine the instability criteria for the flow. It is also shown that for σ> 0 the dependences of the critical Dean number on the parameter η have a minimum observed at η = 0.5. With decrease in channel width and permeability, this effect is leveled.