CFD Analysis into the Breakdown of Catamaran Resistance Based on the Original Formula by Insel and Molland

Abstract

Over the last 40 years, the use of fast catamaran has progressively developed attributed to its unique characteristics on resistance and seakeeping. The advantages have also been applied to military vessels to gain both resistance and seakeeping benefits. The current study focuses on the resistance of catamaran warships to provide less resistance, therefore, the size of engine and emission of toxic gases to the atmosphere. The total resistance of a catamaran will be different from a monohull of equal displacement. There are several factors including viscous interference factors such as φ, which is introduced to take account of the pressure field change around the hull, σ takes account of the velocity augmentation between the two hulls and calculated from an integration of local frictional resistance over the wetted surface, and τ is the wave resistance interference factor change. Those resistance components were developed by Insel and Molland in the 1990s. The investigation discusses the derivation of those components numerically using Computational Fluid Dynamics (CFD) approach. The speeds (hence, the Froude numbers) are varied from 0.2 to 0.6 and the separations between the hulls (S/L) are made between 0.2 and 0.4 so the comparative purposes can be done against the classical work of Insel and Molland and other published data.