Stability of internally mixing flow

Hydrodynamic stability of viscous shear flow resulting from the mixing of two parallel streams of fluid along the centre line of a channel is investigated. A linear stability analysis is employed and eigenvalues are extracted using a variational principle combined with a Rayleigh-Ritz procedure. Velocity profiles for the base flow are obtained from a numerical solution of the laminar mixing problem. Results show a sharp drop in critical Reynolds number as the streams start to mix. However, the flow is generally stable at the mean flow Reynolds number investigated here. These results have practical implications for enhancing mixing and heat or mass transfer in thermal systems of small characteristic dimensions, as found in microelectronic equipment packages.