Impact of density gradients on the fluid flow inside a vibrating cavity subjected to soret effect

Abstract Computational fluid dynamics simulations of thermovibrational flows in a square cavity filled with a water–isopropanol mixture has shown that inaccurate density calculations can predict very different flow behaviours. Specifically, comparison has been made between two density calculation models, viz., a weighted‐average scheme and the Perturbed Chain Statistical Associating Fluid Theory equation of state. While the latter approach predicts a stronger flow in the cavity due to the convective instabilities that are induced by the large spatial gradients in density, the weighted‐average scheme cannot predict this since it does not explicitly depend on the temperature of the mixture. © 2012 Canadian Society for Chemical Engineering