Large eddy simulation of flow and heat transfer in a rotating ribbed channel

The internal cooling passage of a gas turbine blade equipped with ribs is modeled as a rotating ribbed channel. The flow and heat transfer in the ribbed channel have been investigated by conducting large eddy simulations with a dynamic subgrid-scale model. The Reynolds number considered is 30,000 and rotation numbers are 0, 0.1 and 0.3. The time-averaged results show good agreement with the experimental data. By comparing the present data with those of the smooth channel, it is observed that the vortices shed from the rib induce strong wall-normal motions, and they are augmented on the trailing-wall side by the rotation, resulting in a significant increase in the heat transfer due to rotation. It is also shown that the similarity between the streamwise velocity and temperature is significantly destroyed by both the rotation and the rib itself.