Oblique Impingement of Plane Turbulent Jets

Wall pressure and shear stress in the impingement region are studied experimentally and semi-empirical methods for their prediction are developed. The solutions of the corresponding potential flow problem is used to obtain satisfactory estimates of the eccentricity of the stagnation point. The similarity analysis of the classical wall jet is employed for the wall-jet region. Analytical results are substantiated using existing data. The local skin friction factor is shown to be independent of impingement height and angle but to decrease as the −1/5 power of the jet Reynolds number. The wall jet thickness grows linearly at a slope that depends slightly on the Reynolds number. For Reynolds numbers over 20,000, the maximum wall jet velocity decreases as the inverse square root of distance and is independent of the impingement height. The effect of the impingement angle on the velocity is evaluated using the momentum equation and a potential flow analogy.