Some Studies on branch channel Flow

Abstract

In the present investigation, methods are suggested to predict the flow into a branch taking off from a main channel, maintaining subcritical flow in the main and supercritical in the branch channel. The methods are based on (1) concept of constant specific energy along the inlet to the branch channel, (2) dimensional analysis. Experimental coefficients and graphs are presented in order to solve the actual problems in the field. Theoretical approach based on the concept of constant specific energy along the inlet to the branch, to determine the best angle of off?take when the flow in the main channel is subcritical and in the branch it is supercritical is suggested. The theoretical approach has given good agreement with the experimental results. The thesis comprises five chapters. In the first chapter the available literature on the subject is discussed. The theoretical analysis of the problem is given in the second chapter. Third chapter contains the aims, details and procedure of the experiments. In the fourth chapter the results of the experiments are discussed. Fifth chapter gives the various conclusions of the present investigation. In this chapter the definition, scope and the existing literature on the subject are briefly discussed. It is shown that the solution of the problem by conformal representation introduces considerable error when applied to practical problems. The method suggested by Taylor applies only for the condition of subcritical flow in both the main and the branch channels, besides involving laborious trial and error process for determining the flow into the branch. The works of Kiyoshi Tanaka and Akira Murota is only to a specific case of a power branch channel. The effect of angle of off?take on the discharge to the branch stating the studies by M.A. Grishin and Schoklitsch is discussed. A brief review on side weir literature is given. The works of Pattabhiramaiah and Rajaratnam on supercritical flows treating the inlet to the branch as a weir of zero height is discussed.