Numerical investigation into the interaction of resistance components for a series 60 catamaran

Numerical study of the flow around S60 catamaran and S60 monohull, as well as an investigation into interference phenomenon are performed within this paper. Numerical simulations of the free surface and double body viscous flow are carried out for six Froude numbers in the range 0.3-0.55, for four separation ratios in the range 0.226-0.4696 and for monohull. Verification and validation of the obtained results are provided. Validation is performed by comparison with available experimental data and satisfactory agreement is obtained. Firstly, catamaran interference resistance is studied through interference factor based on the total resistance of catamaran and monohull. Afterwards, the interference resistance is investigated through a procedure based on the resistance decomposition, in order to determine the viscous and wave interference effect on the total resistance of catamaran. The form factor for monohull is found to be different than the form factor for catamaran with identical demihulls. Also, form factor for catamaran is found to be in correlation with the separation. Analysing the flow around demihulls, it has been established that the strength of cross flow is correlated to interference resistance. Finally, benefits of CFD based on viscous flow as a tool in catamaran preliminary design are highlighted.