On the side wall effects upon bodies of arbitrary geometry in wave tanks

A numerical model based on using a tank Green function, has been developed to compute the side wall effects on first- and second-order loadings upon bodies of arbitrary geometry in wave tanks. This tank Green function (TGF) is composed of a finite series of open-sea Green functions and an asymptotic part represented by two single integrals whose kernels decrease exponentially with the integral variable. This consistent expression of the TGF permits one to highlight the side wall effects and to give some criteria for the choice of tank width and the measurement duration to limit the reflection of diffraction and radiation waves.

The efficiency of the developed model is shown in the application to hemispheres and a box-shaped barge placed in the center of the wave tanks. The numerical results explain well the irregularities in the experimental measurements and show that the side walls have important effects on the first-order quantities. These effects are much more pronounced on the second-order drift loads.