An hr-adaptive boundary element for water free-surface problems

An hr-adaptive remeshing method is developed for nonlinear 2-D analysis of the free-surface on water. In order to approximate velocity potential and boundary conditions imposed on the free surface, boundary element method and weighted residual method are employed. Weighted average of error estimators of these two approximation methods is introduced on the fret: surface and unique optimum mesh is obtained based on the averaged-error estimator. In the proposed method, the role of h-process is to decide a priori the number of elements required to satisfy an error tolerance. Thus, the h-process has no need to select some elements which have poor accuracy, nor to refine these elements. Optimization of the element distribution is carried out by the r-process for the number of elements decided by the h-process. The proposed method is applied to sloshing in a rectangular container and forced oscillation in a trapezo dal container. Through these analyses, the performance and efficiency of the hr-method are investigated. (C) 1999 Elsevier Science Limited. All rights reserved.