EXPERIMENTAL AND NUMERICAL STUDY ON PROGRESSIVE FLOODING IN FULL-SCALE

A series of full-scale flooding tests was performed with a decommissioned fast attack craft. Various flooding scenarios were investigated and the floating position and progress of the floodwater were carefully measured. Also air compression inside a flooded tank was studied. The results were used to validate a state-of-the-art numerical flooding simulation tool. A comprehensive analysis of the experimental and numerical results is presented. A good correlation is found, especially when the applied permeabilities and discharge coefficients are properly selected. Finally, the stability of the flooded ship was studied by comparing the results of an inclining experiment and calculations with the lost buoyancy method.

Delayed-Detached Eddy Simulations of Film Cooling Effect On Trailing Edge Cutback with Land Extensions

Film cooling effect on trailing edge cutback with land extensions (i.e. landed case) was numerically investigated with the Delayed-Detached Eddy Simulation method. At three rib geometries (i.e. in-line 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 in-line 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 firstly 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.