Finite element modelling of quasi-three-dimensional nearly horizontal flow

A quasi-three-dimensional numerical model is presented and applied to some test problems with constant density. The numerical technique is based on a finite element formulation and the three-dimensional problem is factorized into one- and two-dimensional subproblems. The non-linear advection is treated by use of a weak formulation of the characteristics method and the equations are transformed to ‘sigma’ coordinates.