Experimental study of natural convection in shallow enclosures with horizontal temperature and concentration gradients

Natural convection in low aspect-ratio rectangular enclosures with combined horizontal temperature and concentration gradients is studied experimentally. An electrochemical system is employed to impose the concentration gradients. The solutal buoyancy force either opposes or augments the thermal buoyancy force. Due to a large difference between the thermal and solutal diffusion rates the flow possesses double-diffusive characteristics. Various complex flow patterns are observed with different experimental conditions. The temperature distributions and mass-transfer rates are also studied. A flow instability under certain conditions is reported.