STUDY ON OPEN CHANNEL FLOWS OVER A RIB BY MEANS OF EMPIRICAL MODEL AND NON-LINEAR κ-ε MODEL

Abstract

Rib-like structures in rivers, such as weirs or spur-dykes, have important roles for both flood control and river environment. It is important to clarify the flow characteristics over a rib in open channels to design and maintain the river structures. In this study, two different methods, i.e. an empirical model and a 3D computation, are applied to the flow around a full-span rib with a rectangular section in open channels. In 3D computations, linear and non-linear k-ε models with quadratic terms and cubic terms are employed for the turbulence model. The results in the two methods are compared with experimental results and performances of the models are discussed. It is shown that an empirical model is effective to elucidate the fundamental aspects of the phenomena.