Viscous heating and instability of the adiabatic buoyant flows in a horizontal channel

The stability of buoyant flows occurring in the mixed convection regime for a viscous fluid horizontal plane-parallel channel with adiabatic walls is investigated. basic flow features parallel velocity field under stationary state conditions. There exists duality flows, every prescribed value mass rate across cross-section, caused by combined actions dissipation and buoyancy force. As pointed out previous study, only primary branch dual solutions compatible Oberbeck–Boussinesq approximation. Thus, analysis will be focused on such flows. onset thermal instability small-amplitude perturbations investigated assuming very large Prandtl number, which equivalent to creeping regime. neutral curves critical parametric conditions are determined numerically.