Numerical Analysis of Impingement Cooling Enhanced by Cross-Flow Using a U-Shaped Turbulator

Abstract

This thesis addresses the cooling challenges in gas turbines, focusing on the impact of a U-shaped turbulator placed downstream of impingement jets to enhance cooling efficiency. Traditional cooling strategies employ impingement jets to cool the turbine surface. However, the presence of cross-flow often deflects these jets, diminishing the cooling performance. By introducing a U-shaped turbulator, the cross-flow is redirected, effectively enhancing the jet impact and increasing the heat transfer rates.

The numerical analysis conducted uses Reynolds-Averaged Navier-Stokes (RANS) simulations with the DLR’s TRACE solver and the Menter k-ω SST turbulence model. Results show that the U-shaped turbulator improves the Nusselt number on the target surface by 12% to 28% without substantial pressure loss. This improvement is largely due to increased turbulence and flow redirection facilitated by the turbulator. Findings from this study offer insights into more efficient turbine blade cooling methods, providing a valuable reference for turbine pre-design efforts.