Hydrodynamic modeling of planing catamarans with symmetric hulls

Despite rising popularity of planing catamarans, numerical methods for predicting their hydrodynamics are rather scarce and incomplete. The hydrodynamic interaction between hulls planing parallel to each other is known to become significant when spacing between hulls is sufficiently small. In the present study, a potential-flow method of hydrodynamic sources is applied for modeling steady hydrodynamic characteristics of twin-hull setups. Parametric calculations are carried out for symmetric hulls in variable speed regimes at different spacings, hull aspect ratio, and deadrise angles. Results are presented for the lift coefficient and center of pressure, and some illustrations are given for the water surface elevations. The lift coefficient is found to increase with smaller spacings and higher aspect ratios at moderate and high Froude numbers.