nvestigation of discharge coefficient with one inlet and double outlet hole injection

In order to investigate the flow resistance of the one inlet and double outlet hole used on the blade of the aero-engine, the experiments of the discharge coefficients with various orientation angles of the branch hole were conducted in the low speed wind tunnel. Blowing ratios changes from 0.2 to 2.0. The Reynolds numbers based on the mainstream velocity and the diameter of the holes are 6200, 9300 and 12400 respectively. The results shows that the discharge coefficients of the one inlet and double outlet holes which have the orientation angles of 45° and 90° are larger than those of the other shaped holes up to 15%. Not the Reynolds numbers and orientation angles, but the changes of blowing ratios, are the dominant reasons of the change of the discharge coefficients at low blowing ratios. The changes of blowing ratios, Reynolds numbers and the orientation angle of the branch holes have considerable effect on the discharge coefficients at high blowing ratios. The one inlet and double outlet holes with 45° orientation angles is necked to be the optimal one based on the discharge coefficients and cooling effectiveness.