Abstract
Three-dimensional mixed convective heat transfer in horizontal square duct with heated bottom and side walls were simulated in transient process by solving three dimensional governing equations. The kinematic viscosity and thermal conductivity of the fluid depend on temperature. Flow and heat transfer characteristics were examined transiently. The flow was spiraled along main direction and its pitch increased with time. Reverse flow appeared at the starting point of heated section near the upper wall and the length increased with time. After two recirculation flows were generated near the side walls across the section, two small recirculation flows were produced near the bottom wall. The heat transfer behavior corresponding to the flow was discussed.
