Numerical and experimental studies on hydrodynamic performance of a small-waterplane-area-twin-hull (SWATH) vehicle with inclined struts

A small-waterplane-area-twin-hull (SWATH) vehicle with inclined struts was investigated by numerical and experimental methods. Seakeeping performance was studied firstly based on the STF (Salvesen, N., Tuck, E. O. and Faltinsen, O. M. (1970). Ship motions and sea loads. Transactions-Society of Naval Architects and Marine Engineers. No. 78:250-287) strip theory. Results show that the inclined struts demonstrates improved seakeeping performances by comparison with a vertical-strut SWATH and an NPL (National Physical Laboratory) catamaran. 3D numerical simulations adopting an RANS method and model tests in the towing tank were carried out both in calm water and in regular waves. Numerical simulations have been validated by comparison with laborotary tests. As negative added resistance has been observed both in the model tests and in the numerical simulations, it can be concluded that the inclined struts, which could make use of wave energy, can give rise to a reduction of power required in waves.