Mixed convection instability in a viscosity stratified flow in a vertical channel

The present study examines the linear instability characteristics of double-diffusive mixed convective flow in a vertical channel with viscosity stratification. fluid is modeled as an exponential function temperature and concentration, activation energy parameter determining its sensitivity to variation. Three scenarios are considered: buoyancy force due thermal diffusion only, solute acting same direction, opposite directions. A generalized eigenvalue problem derived solved numerically for stability analysis via Chebyshev spectral collocation method. results indicate that higher values lead increased stability. Additionally, when both buoyant forces act directions, Schmidt number has stabilizing destabilizing effects across range parameters, similar case pure diffusion. Furthermore, solutal-buoyancy-opposed base found be most stable, while solutal-buoyancy-assisted least stable. As expected, increase Reynolds shown decrease critical Rayleigh number.