CFD-based Study On The Resistance Performance Of Inverted V-shaped Channel Hydroplane

Planing craft has tremendous advantages including small dimensions, high speed, simple structure, and low cost in manufacturing and maintenance, it has been widely used in military and civilian fields. But, there exists kinds of problems for monohull planing craft and catamaran planing craft. For monohull planing craft, the resistant grows rapidly with the increasement of speed and it is also has bad seakeeping. For catamaran planing craft,wave-making is remarkable when operation .According to the problems mentioned above ,this paper puts forward a new type of boat-inverted V-shaped channel hydroplane. In terms of appearance and structure, this hull is consist of two asymmetric demihulls with inward-Inclined bottom planning surface and a circular arc channel. The inverted V-shaped channel hydroplane has excellent hydrodynamic performance of low resistant performance,high seakeeping performance, and minor wave-making during forward motion . This paper made a preliminary theoretical research on inverted V-shaped channel hydroplane using the Finite Volume Method (FVM) based commercial CFD software Star-ccm-+.Firstly, the virtual towing tank model was built and then numerical simulation approach fit for high speed planning craft with channel was proposed. It was discussed in this paper that the influence of surface mesh size and near wall mesh division on calculation accuracy .The numerical method was validate by comparing calculated results with experimental data.Secondly, the hull feature and working mechanism of the inverted V-shaped channel hydroplane are introduced. The hydrodynamic characteristics are analyzed by the CFD technique. Comparisons of hull behavior, wave-making, and pressure distribution were carried out between the ordinary catamaran planning crafts and monomer planning craft,analyzed the similarities and differences of the hydrodynamic performance of those three hull types and explained the priority of superiority resistance performance of the new hull.Thirdly, the analysis of the fluid field around the inverted-V shaped channel hydroplane is given to elaborate the channel hydrodynamic mechanism. Then a series of models with different channel radius, width, and height are calculated to discuss the influence of the channel geometric factors on the resistance performance of inverted V-shaped channel hydroplane.Finally, this paper puts forward a scheme of step settings for this ship based on the mechanism of drag reduction by the steps. A model without steps was compared with a model with step to verify the validity of drag reduction effect of steps.