Effect of Temperature Upon Double Diffusive Instability in Navier–Stokes–Voigt Models with Kazhikhov–Smagulov and Korteweg Terms

Abstract We present models for convection in a mixture of viscous fluids when the layer is heated from below and simultaneously pointwise volume concentration one heavier below. This configuration produces problem competitive double diffusion since heating promotes instability, but greater density fluid stabilizing. The are linear type which may contain Kelvin–Voigt terms, gradients due to appear strongly governing equations. give rise Korteweg stresses, also be described by theory Kazhikhov Smagulov. systems equations thus highly nonlinear. instability surface threshold calculated this found have complex nonlinear shape, very different ones classical thermohaline Navier–Stokes fluid. It shown that Kazhikhov–Smagulov terms term play key role acting as stabilizing agents associated effect Quantitative values displayed showing Kelvin Voigt have. stability addressed means generalized energy deriving results depending on underlying employed.