Open Channel Flow Over Submerged Obstructions: An Experimental and Numerical Study

This paper reports on experimental and computational investigations of water flow over two-dimensional obstacles in an open channel. Both triangular and semi-circular obstacles are considered in order to study the effects of obstacle type and size on the flow. The upstream flow is subcritical while the downstream flow is supercritical in all the cases discussed. The results of the experiments indicate that the downstream Reynolds number increases and appears to approach an asymptotic value as the obstacle height is increased. The upstream Reynolds number, on the other hand, decreases linearly as the obstacle height is increased. For the cases involving triangular obstacles, comparisons are presented between the results of the experimental measurements and the computational simulations as well as with available analytical solutions for inviscid flow. The comparisons point to the conclusion that the fluid rotational activity has a negligible effect on the overall flow in the open channel.