Transport phenomena of a stratified fluid in a rapidly rotating container

Abstract

A Numerical study is made of flow and convective transfer phenomena inside circular cylindrical cavities which steadily rotate for its own axis of center are obtained. Convective transport phenomena and fluid flows are closely connected problems. In this study, the effects of fluid flow generated by rotation of a solid and buoyancy effect on transport phenomena are handled. Sparrow ＆ Chaboki``s mass transfer experimental research presented surfaces averaged Sherwood numbers for a certain range of Reynolds number and the aspect ratio of the cup. But, due to the limits of experimental research, local Sherwood number profiles, flow and concentration fields are not shown. In this study, with computation technique, previous experimental works are resimulated numerically. Not only surface averaged Sherwood number, but flow structure, concentration fields and local Sherwood number profiles are presented and analyzed. The effects of Reynolds number and aspect ratio on the heat transfer and fluid flow are numerically examined. To complement earlier experiments, buoyancy effects are handled. The temperature at the cylinder sidewall is lower than that of the surroundings. The relevant nondimensional parameters are identified. The governing Navier-Stokes equations, with the Boussinesq-fluid approximation, are solved numerically. The rotational Reynolds number is large, and, the cylinder aspect ratio is Ο(1). The three-component velocity and temperature fields are portrayed. When the base surface is insulated, for the Richardson number Ri≥Ο(1), the meridional flow weakens, the boundary layer-like character in the temperature field diminishes, and the azimuthal flow approaches that of a rigid-body rotation. When the base surface is transferring, the velocity fields are little altered from those of the insulated base, but appreciable differences are seen in the temperature fields. Physical explanations and rationalizations are offered on the basis of numerical results. Detail...