Document Type : Research Paper
PhD. Candidate, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
Professor, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
Professor, Vienna University of Technology, Austria
The assumptions considered in developing the Saint-Venant equations limit their application in many practical situations. The modified Boussinesq equation was presented to overcome the limitation imposed by Saint-Venant equation due to the presence of non-hydrostatic pressure distribution and steep slope. In this paper a computational model was developed for solving the modified and the traditional Boussinesq equations for unsteady flow condition. Verification of the numerical results was accomplished by compiled discharge experimental data in the range 7 and 30 l/s. The relative errors associated with the results of both equations were calculated. The average relative errors were 4 and 18 percent respectively for the modified Boussineq and the traditional one in predicting discharge. This highlighted the importance of the slope impact on the accuracy of the results. Also, the modified equation is able to produce the stage-dischrge relationship for trapezoidal weir with high accuracy.