2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference


Title
NUMERICAL STUDY COMPARING ESTIMATED MANNING’S COEFFICIENTS USING THE DIRECT STEP METHOD


Author(s)
Mrs. Nadia Hajjout, École Polytechnique de Montréal (Presenter)
Dr. Mahdi Tew-Fik, École Polytechnique de Montréal, Département des génies civil, géologique et des mines (CGM)
Abstract

Two numerical experiments were conducted, the first one involving a straight prismatic channel to simulate the unidimensional flow and the second experiment uses a curved rectangular channel to emphasize the 2D flow characteristics. The flow in both cases is modeled using a 2D model, SRH-2D, using given roughness parameters, Manning’s coefficients. Afterwards, the results of both numerical experiments are used to recalculate Manning’s coefficients, in each case study, by the direct step method (Slope energy) using the channel's centerline for the calculations. The aim of this paper is to compare the estimated Manning’s coefficients, for a prismatic and rectangular channel, in the case where the flow is mainly unidimensional and when the 2D effects are more obvious. In general, a good agreement is observed between the original Manning’s coefficients and the estimated one in the straight configuration whereas the second configuration demonstrates a divergence between suggested and calculated Manning’s coefficients.