This work experimentally investigates the effects of confined cross flow and geometrical parameters in impingement flows on the jet discharge coefficient, Cd. Such cooling configurations are common in the gas turbine industry and all properties were chosen to be applicable in real applications.
The effect on Cd was studied for square edged orifices with thickness to diameter ratio l/d = 1 in the range of jet to cross flow mass velocity ratio 0 ≤ Gc/Gj ≤ 6 at a jet Reynolds number of 104. The distance between orifices in the span wise yn/d = 2.5–8 and stream wise xn/d = 2.5–7 directions as well as the spacing to the target plate z/d = 1–3 were investigated.
Generally, the conclusions from previous studies were confirmed. An exception to this was the observed increase of Cd with increasing Gc/Gj for Gc/Gj < 0.5.
A correlation was developed for the discharge coefficient with the new experimental data as function of z/d, yn/d and Gc/Gj. The resemblance to the measured data was excellent with a maximum deviation of 4%.