NONLINEAR RESONANCE OF FREE-SURFACE WAVES IN A CURRENT OVER A SINUSOIDAL BOTTOM - A NUMERICAL STUDY

We examine the free surface flow over a fixed bed covered by rigid sin usoidal dunes. The mean current velocity is near the critical value at which the linearized theory predicts unbounded response. By allowing transients we examine the instability of the steady and nonlinear solu tion of Mei (1969) and the possibility of chaos when the current has a small oscillatory component.