Delayed-Detached Eddy Simulations of Film Cooling Effect on Trailing Edge Cutback With Land Extensions

Abstract

Abstract Film cooling effect on trailing edge cutback with land extensions (i.e., landed case) was numerically investigated with the delayed-detached eddy simulation (DDES) method. At three rib geometries (i.e., inline rib arrays, six-row pin-fin arrays, and five-row pin-fin arrays) and five blowing ratios (i.e., M = 0.5, 0.8, 1.1, 1.5, and 2.0), film cooing effectiveness, coherent vortex structures, and discharge coefficients for the landed cases were analyzed and compared with baseline cases (i.e., cutback without land extensions). The results show that land extensions have significant influences on coherent flow structures, vortex energy levels, film cooling effectiveness, and discharge coefficients in cutback region. Different from the baseline cases, the dominant vortex structures in landed cases exhibit the “double helix” (for cutback with inline rib array) or “strip” pattern (for cutback with pin-fin arrays), and the thickness of mixing region in landed cases is decreased. Among three rib geometries, the trailing edge cutback with six-row pin-fin arrays has the worst cooling effect for both baseline and landed cases. Compared with the baseline cases, the discharge coefficients for the landed cases are decreased by about 21.4%. With land extensions, the overall film cooling effectiveness on cutback is decreased first and then increased with increasing blowing ratio. Among all investigated cases, cutback with five-row pin-fin arrays for the landed case performs the best film cooling effect at M = 0.5.