Free surface flow : experiments in a hydraulic channel with the water at rest and a moving bottom

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.When considering the problem of water waves, induced by an obstacle, in a fluid domain of finite depth, the main assumption is generally to consider the water as an inviscid fluid, which means that the velocity profile is not sheared but constant upstream from the bottom up to the free-surface. The objective of the experiments presented in this paper is to produce a free-surface flow over an obstacle, in a hydraulic channel, with a constant velocity profile upstream. To achieve this, we carried out an original device. The channel, with an obstacle lying on its bottom, is filled with a quantity of water at rest. A drive system moves, at a constant adjustable velocity, the bottom of the channel generating then a relative movement of the water with respect to the obstacle. Measurements of the wavelengths are performed and compared with that given by the theory.