Experimental and numerical study of the anti-crossflows impingement cooling structure

The jet impingement array is a commonly used cooling structure for modern HPT vanes. The spend coolant from upstream impingement holes (crossflows) can disrupt and deflect the downstream jets in the array leading to a decrease in heat transfer intensity. A novel multi-row impingement cooling structure, named the Anti-Crossflows (ACF) cooling structure, that could reduce the negative effect of crossflows was studied for the cooling of convectively cooled vanes. The ACF impingement cooling structure uses the corrugated impingement plate to increase the sectional area for the outflow of crossflows. More than 20 experiments with transient liquid crystal (TLC) measurements under different geometry and Reynolds number were applied to validate the numerical methods. The flow and heat transferring characteristics of the prototype and ACF impingement cooling structure were thoroughly investigated by a set of numerical studies based on 3D RANS methods. It was found that the novel ACF impingement cooling structure had better cooling performance compared with traditional impingement cooling, including lower flow resistance and more homogeneous heat transferring intensity on the target surface. This is because the increased sectional area for crossflows reduces the momentum of crossflows at the downstream impingement jets, and the disruption and deflection on jet flows are significantly weakened. Furthermore, the ACF impingement cooling structure was implemented in a convectively cooled turbine vane and investigated numerically. The results showed that the ACF impingement cooling structure was promising for the vane by improving the performance of vane cooling system. The partial wall temperature of the vane was reduced by 10–30 K with the same pressure drop and mass flow of cooling air