Effect of wall curvature of an asymmetric subsonic impinging jet: DNS study

We report on Direct Numerical Simulation (DNS) of a subsonic confined jet impinging on a curved surface. The configuration resembles a turbine leading edge cooling system. The bulk Reynolds number (based on bulk velocity Ub and jet diameter D) is 3300. The impinging wall was kept at a constant temperature higher than the jet bulk temperature. Comparisons with the jet impinging on a flat plate are carried out. Our major findings are that the turbulent flow field is affected by the shape of the impinging wall, leading to an asymmetric development of turbulent structures. The frequencies which dominates the excess heat transfer mechanism change with respect to the reference case, changing the average heat transfer into the hot wall.