Investigation of transition in a natural convection flow in an inclined parallel Plate Channel

In an inclined parallel plate channel, the influence of the angle of inclination on the transition of the free con-vection flow has been explored. Three dimensional large eddy simulations have been carried out employing the wall adaptive local eddy viscosity sub-grid scale model. The inclination angles of 15 degrees, 30 degrees, and 60 degrees with respect to the horizontal are considered. The upper wall of the parallel plates is kept at constant heat flux, while the bottom one is adiabatic. The Grashof number, Gr(L) considered in the present study is 8.22 x 10(12). The variation of the transition zone of the flow with variation in inclination angle is shown using thermal boundary layer for-mation, variation of velocity fluctuations, Nusselt number variation, and Q criterion. Investigation of the thermal boundary layer shows the formation of flume structure at the early stage of the flow in the case of lower inclination of the channel. As the degree of inclination increases, the transition is delayed, and the transition region shifts downstream.