TY - JOUR T1 - Numerical simulation of bedload sediment transport with ability to model dry interfaces using an augmented Riemann solver TT - شبیه‌سازی عددی پخشیدگی رسوب بستر با قابلیت مدل‌سازی سطوح خشک با استفاده از حل‌کننده ریمن تقویت‌شده JF - mdrsjrns JO - mdrsjrns VL - 18 IS - 5 UR - http://mme.modares.ac.ir/article-15-16517-en.html Y1 - 2018 SP - 241 EP - 249 KW - Shallow Water KW - Godunov KW - Conservation laws N2 - Various numerical methods have been developed for solving morphodynamic systems, among which the finite-volume method has been widely employed in recent years. This paper presents an efficient finite volume technique for simulation of bedload sediment transport near dry interfaces. The equations governing sediment transport in channels and rivers comprise the shallow water equations and Exner equation. By considering a novel velocity for Riemann waves, shallow water and Exner equations are solved using a weakly-coupled scheme based on an augmented Riemann solver. In this approach the morphodynamic equation is first solved and the updated bedload changes with the same Riemann structure are used as a source term within the shallow water equations. Augmented Riemann solver is based on a decomposition of an augmented vector—the depth, momentum as well as momentum flux and bottom surface. The proposed numerical model is first used for the simulation dam break flow over a mobile bed. Then, dam failure due to over-topping flow is considered and the computed results are compared with the experimental data.These numerical results indicate that the defined weakly coupled method developed based on an augmented Riemann technique is able to be used for modelling bedload sediment transport near dry interfaces with highly accurate and exhibits a very good agreement with the experimental data for test cases. M3 ER -