Double-diffusive convection in a rectangle with opposing horizontal temperature and concentration gradients

摘要: A numerical study is made of double-diffusive convection in a rectangular cavity with combined horizontal temperature and concentration gradients. The boundary conditions at the vertical side walls are imposed such way that thermal solutal buoyancy effects counteracting, resulting an opposing gradient flow configuration. Numerical solutions to governing full time-dependent Navier-Stokes equations large (Rt) (Rs) Rayleigh numbers acquired. essential details flow, fields described for Lewis number. time evolutions these portrayed. Distinct regimes steady-state identified as ratio Rp ( = RsRt) varies over wide range. structures thermal, velocity layers near wall examined. When moderate, multi-layered structure interior clearly depicted; attendant S-shaped field step-like distribution brought into focus. existence layered core strongly corroborative results prior experimental visualizations. Based on data, mean Nusselt number Nu Sherwood Sh tabulated varying values Rp. As increases from very small value, decreases monotonically towards value characteristic conductive transfer; however, reaches minimum when takes moderate value. This behavior qualitatively consistent previous findings.