The effect of wall slip on the stability of the Rayleigh-Bénard Poiseuille flow of viscoplastic fluids

摘要

This work investigates the effect of wall slip on the stability of the Bingham Rayleigh-Bénard Poiseuille flow. The steady state of the Bingham plane Poiseuille flow is characterized by an unyielded region of 2yb width and two sheared regions close to the walls with both no-slip and slip conditions at the walls. A linear stability analysis of this flow with slip conditions is proposed in this paper. The slip boundary conditions case leads to flow destabilization compared with the results obtained in the no-slip case. Critical conditions are modified by varying Cf, the friction number. For Cf30 the flow is stabilized, i.e. Rac values increase and finally tend to that of the no-slip case when Cf>1000. Furthermore, for 1