Spelling suggestions: "subject:"monotonic upwind scheme"" "subject:"monotonico upwind scheme""
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Source term treatment of SWEs using surface gradient upwind methodPu, Jaan H., Cheng, N., Tan, S.K., Shao, Songdong 16 January 2012 (has links)
No / Owing to unpredictable bed topography conditions in natural shallow flows, various numerical methods have been developed to improve the treatment
of source terms in the shallow water equations. The surface gradient method is an attractive approach as it includes a numerically simple approach
to model flows over topographically-varied channels. To further improve the performance of this method, this study deals with the numerical
improvement of the shallow-flow source terms. The so-called surface gradient upwind method (SGUM) integrates the source term treatment in the
inviscid discretization scheme. A finite volume model (FVM) with the monotonic upwind scheme for conservative laws is used. The Harten–Lax–van
Leer-contact approximate Riemann solver is used to reconstruct the Riemann problem in the FVM. The proposed method is validated against published
analytical, numerical, and experimental data, indicating that the SGUM is robust and treats the source terms in different flow conditions well.
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Shallow sediment transport flow computation using time-varying sediment adaptation lengthPu, Jaan H., Shao, Songdong, Huang, Y. 07 1900 (has links)
Yes / Based on the common approach, the adaptation length in sediment transport is normally estimated in the temporal
independence. However, this approach might not be theoretically justified as the process of reaching of the sediment
transport equilibrium stage is affected by the flow conditions in time, especially for those fast sediment moving flows,
such as scour-hole developing flow. In this study, the 2D shallow water formulation together with a sediment
continuity-concentration (SCC) model were applied to flow with mobile sediment boundary. A time-varying approach
was proposed to determine the sediment transport adaptation length to treat the flow sediment erosion-deposition rate.
The proposed computational model was based on the Finite Volume (FV) method. The Monotone Upwind Scheme of
Conservative Laws (MUSCL)-Hancock scheme was used with the Harten Lax van Leer-contact (HLLC) approximate
Riemann solver to discretize the FV model. In the flow applications of this paper, a highly discontinuous dam-break
fast sediment transport flow was used to calibrate the proposed time-varying sediment adaptation length model. Then
the calibrated model was further applied to two separate experimental sediment transport flow applications
documented in literature, i.e. a highly concentrated sediment transport flow in a wide alluvial channel and a sediment
aggradation flow. Good agreements with the experimental data were presented by the proposed model simulations. The
tests prove that the proposed model, which was calibrated by the discontinuous dam-break bed scouring flow, also
performed well to represent the rapid bed change and the steady sediment mobility conditions. / The National Natural Science Foundation of China NSFC (Grant Number 20101311246), Major State Basic Research Development Program (973 program) of China (Grant Number 2013CB036402) and Open Fund of the State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University of China (Grant Number SKLH-OF-1103).
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