Abstract: A fully nonlinear numerical flume model is developedbased on the time-domain higher-order boundary element method. The fullynonlinear free surface boundaries are satisfied on the instantaneous freesurface in this model. The mixed Eulerian-Lagrangian scheme is adopted totrack the transient free surface with the fourth-order Runge-Kutta methodfor refreshing wave profile and velocity potential at the next time step. Animage Green function is utilized to increase the speed of computation. Themeshes are regidded at each time step to avoid numerical instabilitiescaused by mesh motions. The experimental study on evolution of waves over asubmerged bar in uniform current is carried out in a wave flume. And thenumerical solutions are compared well with experimental data. The effects ofcurrents and the submerged bar on the higher-order harmonic waves are furtherstudied.