Experimental investigation on the effect of impingement hole location on vane impingement/film cooling

In order to study the effect of impingement hole location on the ICE (Integrated Cooling Effectiveness) of turbine vanes, the heat transfer experiments of vanes with low thermal conductivity were conducted. The test vanes include typical film cooling without jets (Vane 0), typical impingement/film cooling with centerline normal jets (Vane 1), and swirl impingement/film cooling with offset jets (Vane 2). When the BR (Blowing Ratio) was relatively higher, the heat transfer between the coolant and the target surface was enhanced by jet impingement, and the ICE of Vanes 1 and 2 was 3.6-8.6% higher than that of Vane 0. The jet impingement enhanced region was relatively independent of the film hole coverage region because the offset impingement holes were located at the film hole inlet upstream. It made the vane surface temperature distribution more uniform and ICE of Vane 2 slightly higher. However, when the BR was relatively small, the ICE of Vane 1 with centerline jets was larger than that of Vane 0, and the ICE of Vane 2 with offset jets was lower than that of Vane 0.