NUMERICAL SIMULATION OF INTERNAL WAVES USING A SET OF FULLY NONLINEAR INTERNAL-WAVE EQUATIONS

Abstract

Internal waves in a two-layer system are simulated using a set of fully nonlinear internal-wave equations, which was derived on the basis of a variational principle without any assumptions of wave nonlinearity and dispersivity. Computational results of interface displacements up to each order on the vertical length scale of motion are compared with calculation results obtained using a Boussinesq-type internal-wave model or the existing experimental data. In a long-wave case, interface displacements obtained by the proposed model with more than two vertically distributed functions of velocity potential are in harmony with those by the Boussinesq-type model, as well as the experimental data especially in the wave number. In an intermediate-wave case, the present model shows different results from those through the Boussinesq-type model, which should not be applied to this case without enough consider- ation of the wave dispersivity.