NUMERICAL SOLUTIONS OF SAINT-VENANT EQUATIONS

Abstract

With the increasing popularity of finite element method in recent years, investigations pertaining to the solution of Saint Venant Equations have taken place in the literature. With the use of finite difference scheme, it is possible to encounter oscillations in the falling limb of the outflow hydrograph. To study the relative advantage of finite element method over finite difference scheme, an example in which the finite difference scheme produces the oscillations in the outflow hydrograph, is considered in this study. A software is developed for the applicatrion of finite element method. Effects of various factors including element size, time step, location of control section, Manning's 'n' have been studied.Some of the salient features of the study includes the removal of oscillations from the outflow hydrograph, sensitivity of outflow hydrograph to the value of Manning's 'n' and its unsensitivity to the location of downstream contrtol section as well as the time step and weighting factor in a certain range.