Computational Investigation into Pressure and Viscous Resistances of a Catamaran in Calm Water

The presence of incident divergent waves between two demi-hulls on catamaran ship will attempt to generate a non-linear hydrodynamic behaviour, which inherently induced an accuracy of predicting her total resistance (RT). Correspondingly, this becomes an attractive factor to propose a more reliable prediction of the total ship’s resistance through quantifying both of pressure and viscous resistances components. This paper presents computational investigation into predicting the viscous (CV) and pressure coefficients (CP) in calm water condition; whilst the rationale behind the analysis results explained. Several parameters have been taken into accounts in the computational simulation such as the effect of lateral separation (S/L) and longitudinal staggered (R/L) ratios at various Froude numbers. The preliminary validation shows that the total ship’s resistance at various S/L and R/L ratios constitute a fairly good agreement as compared to the experimental results. In addition, the CFD simulations revealed that the highest CV and CP occurred at the Fr= 0.47. The comparison in various lateral separation ratio showed that the symmetrical catamaran produced highest CV and CP at S/L=0.2 and S/L=0.4, respectively. Meanwhile, the staggered catamaran with S/L=0.2 produces highest the values of CV and CP at R/L=0.4 and R/L = 0.2, respectively. It is merely concluded that the current computational prediction provides useful outcomes particularly to estimate the effective power at preliminary design stage.