Modelling turbulent flow from dam break using slow manifolds

Abstract

We present a novel approach based on centre manifold techniques to describe the large scale dynamics of the mean turbulent dam-break flow. We avoid empirical assumptions about the cross-stream profile of the velocity; instead a solution is obtained using free surface and bed boundary conditions that accommodate constant turbulent shear as an approximately neutral mode. We describe the turbulent dynamics across the flow, and identify important factors affecting the turbulent dissipation in the lateral direction. Available experimental data verify the results.