A PSEUDOSPECTRAL p-TRANSFORMATION MODEL OF 2-D NONLINEAR WAVES

to be extremely important in modelling transi-ent free-surface #ow problems, including standing waves in "xed tanks, liquid slosh-ing in base-excited tanks, earthquake-induced transient free-surface #ows, and in the design of large diameter o!shore structures where loading is in the inertial regime. Al-though "rst- (linear) and second-order potential #ow analytical solutions have been derived for simple geometries based on perturbation expansion techniques, free-surface #ows are often strongly a!ected by higher-order components. For example, the &&ringing’’ of large diameter structures in steep waves can cause high transient stresses with sig-ni"cant contributions from third-and higher-order wave components. In such cases, low-order solutions of the nonlinear di!raction problem are insu$cient to predict the load-response behaviour of the o!shore structure. Extension of the perturbation procedure to higher than second order is very cumbersome, and an alternative numerical modelling strategy seems desirable. Nonlinear time-domain simulation then is an appropriate ap-proach. In the past, much attention has been paid to modelling transient free-surface potential #ows by means of the boundary-element technique [e.g., Lin et al. (1984), Dold & Peregrin