Parametric investigation of drag reduction for marine vessels using air-filled dimpled surfaces

The drag reduction for the marine vessels using air-filled dimpled surfaces has been investigated based on different proposed geometries. The set-up of a drag measurement rig to determine the drag reduction experimentally and to provide means for validation of the computations have been conducted. The computational analysis of dimpled surfaces with the trapped air has also been investigated by using the Large-eddy simulations and volume-of-fluids models. The corresponding results have shown that the numerical results are in excellent agreement with the water channel experimental data and the drag reduction effect is obvious. It can be clearly observed that a series of the bubbles and vortices appeared near the dimpled surfaces and dowstream by contouring the phases of the fluids. The optimisation of dimple shape and size and the analysis of performance gains on marine vessels using drag reduction techniques have also been investigated in detail.