Strategies for finite element modelling of three dimensional hydrodynamic systems

The simulation of a system composed entirely of three dimensional elements is computationally very expensive and little practical analysis has been undertaken. In an effort to reduce cost the author in a previous paper presented a simplified three dimensional model that used the hydrostatic pressure approximation to eliminate the vertical momentum equation and a transformation of the basic equations to directly solve for the free surface profile. This paper will examine approaches to the reduction of simulation costs within the framework of the original approach and modifications to the basic formulation to improve the performance of the model when the flow bath is over system with variable bed elevations. Examples will be presented to demonstrate the effectiveness of these modifications.