Ecology, Environment and Conservation Paper

NUMERICAL MODELING OF THE CHANGES OF FLOW FREE SURFACE IN 90 DEGREE INTERSECTION IN RECTANGLE CHANNEL WITH FLOW 3D SOFTWARE

Shahab Goorani and Fariborz Yosefvand

Abstract

In this study, the results of numerical model were comprised with laboratory amounts. To this aim, the results of changes in flow free surface of numerical model were comprised with laboratory amounts of Weber et al., (2001) for the longitudinal profiles of the flow in main channel. The location of numerical result amounts and their comparison with laboratory ones of Weber et al., (2001) were shown for different longitudinal axes. In this study, numerical amounts with laboratory ones were comprised from three longitudinal axes 1-1, 2-2 and 3-3 in the vicinity of internal wall of the main channel, central axis of the main channel and the vicinity ofexternal wall of the main channel, respectively. The quantity of mean absolute percentage error (MAPE) of longitudinal profiles of flow free surface was arranged for different intersections. The error of numerical model to predict changes of flow free surface for longitudinal axis 1- 1 was 2.232% which the comparison of numerical results and laboratory ones are depicted. The profile of flow free surface in central axis of the main channel with mean absolute error was estimated to. 125% which the comparison of the location was also drawn. Longitudinal profile of flow free surface on the central axis of the main channel with mean absolute error that was estimated 2.125% and the comparison of this location was also drawn. With longitudinal 3-3 the amount of MAPE is 1.792 and the comparison of numerical and laboratory results of this longitudinal profile were shown in the following figures. An important point to notice is that by accessing to the external wall of the main channel, the amount of mean absolute percentage error was reduced. Therefore by receding from the intersection the characteristics of the flow free surface were predicted accurately because of the reducing the commissure of two numerical model flow.