Influence of the Transverse Temperature Drop on the Stability of Two-Layer Fluid Flows with Evaporation

The linear stability of combined evaporating liquid-vapor-gas mixture flow is investigated under conditions of inhomogeneous heating within the framework of the conjugate problem. The exact solution of the Navier-Stokes equations in the Boussinesq approximation is used to describe the two-layer flow. The solution takes into account the influence of both nonzero streamwise and transverse temperature gradients and the direct and inverse thermal diffusion effects in the vapor-gas layer and on the phase interface. The influence of the applied external thermal load on the main flow parameters, their structure, the volume vapor content, the mass evaporation rate, and the stability is studied for systems with various liquid-layer thicknesses. The typical forms of characteristic perturbations are distinguished and the critical loads that lead to loss of stability at small transverse temperature drops are determined.