Pressure distribution computed by wave-interaction theory for adjacent multiple bodies

In spite of a mathematical limitation that each interacting body must be far enough apart from the other bodies, the wave interaction theory has been used successfully even for a case where the separation distance between the bodies is virtually zero. Numerical investigation is made in this paper on the practical applicability of the wave interaction theory by considering four identical box-shaped bodies as a simplified example and comparing computed results with correct ones obtained by the higher-order boundary element method. It is shown that the wave force in the horizontal direction can be obtained favorably by the interaction theory even if the separation distance between the bodies is very small. To make reasons of this somewhat peculiar phenomenon clear, not only the integrated hydrodynamic force but also the pressure distribution on the body surface is calculated and compared with the results by the higher-order boundary element method. Discussion is made on whether the pressure is correctly obtained on the regions very close to adjacent bodies and fortuitous cancellation in the integration of the pressure occurs between the two vertical planes in close proximity.