Sharif University of TechnologyScientia Iranica1026309825520181001Numerical modelling of flow field in compound channels with nonprismatic floodplains24132424421510.24200/sci.2017.4215ENB. RezaeiDepartment of Civil Engineering, Bu

Ali Sina University, Hamedan, IranH. AmiriDepartment of Civil Engineering, Bu

Ali Sina University, Hamedan, IranJournal Article20160523In this paper an attempt has been made to study flow field in compound channels with nonprismatic floodplains. A three dimensional computational fluid dynamic (CFD) model is used to calculate the velocity distribution, secondary flow circulation and boundary shear stress in nonprismatic compound channels with two different convergence angles of 3.81<sup>o</sup> and 11.31<sup>o</sup>. The ANSYSCFX software and <em>ke</em> turbulence model is used to solve Reynolds Averaged NavierStokes (RANS) equations. The results of the numerical modeling were then compared to the experimental data on nonprismatic compound channels with the same convergence angles. The study shows that, more or less, the <em>ke</em> turbulence model is capable of predicting the velocity and boundary shear stress distributions along the flume fairly well, especially for convergence angle of 3.81<sup>o</sup>. Also by increasing relative depth, discrepancy between numerical and experimental data decreases. The results of modeling show that the <em>ke</em><em> </em>turbulence model is able to predict secondary flow circulations in the main channel, created by the mass exchange between the floodplains and the main channel.http://scientiairanica.sharif.edu/article_4215_0a8a861f327d14d3f5b3bc4e4d71dced.pdf