Optimal Shape Design of a Two-Dimensional Asymmetric Diffuser in Turbulent Flow

An optimal shape of two-dimensional asymmetric diffuser in turbulent flow with maximum pressure recovery at the exit is numerically obtained using a mathematical theory. The Reynolds number based on the bulk mean velocity and the channel height at the diffuser entrance is 18,000. The optimality condition for maximum pressure recovery is obtained to be zero skin friction along the diffuser wall. The turbulent flow inside the diffuser is predicted using the 2k v fe--- model and optimal shapes are obtained through iterative procedures to satisfy the optimality condition for six different geometric constraints. For one of the optimal diffuser shapes obtained, large eddy simulation is carried out to validate the result of shape design.