Research Reports |
Title: | Insights from Depth-Averaged Numerical Simulation of Flow at Bridge Abutments in Compound Channels |
Authors: | Reinaldo Morales and Robert Ettema |
University: | University of Wyoming |
Publication Date: | Jul 2011 |
Report #: | MPC-11-237 |
Project #: | MPC-307 |
TRID #: | 01354611 |
Keywords: | bridge abutments, channel flow, flood plains, hydraulic structures, numerical analysis, simulation |
Type: | Research Report – MPC Publications |
Two-dimensional, depth-averaged flow models are used to study the distribution of flow around spill-through abutments situated on floodplains in compound channels and rectangular channels (flow on very wide floodplains may be treated as rectangular channels). The study leads to useful insights regarding distributions of flow velocity, unit discharge, and boundary shear stress at spill-through abutments. It also presents insights from extensive assessment of uncertainty associated with the use of depth-averaged modeling of flow at abutments. The study, by showing how abutment flow fields adjust in response to variations of abutment length, floodplain width, and main channel dimensions, yields important trends regarding the magnitude of amplification factors for depth-averaged velocity, unit discharge, bed shear stress, and distance to peak unit discharge. The study comprises a much broader range of abutment lengths, channel shapes, and floodplain dimensions than heretofore reported in the literature. The study's insights, from its assessment of uncertainty associated with the use of depth-averaged modeling of flow at abutments, yield a relationship for estimating the optimum mesh size for use with depth-averaged models. The study also gives focused recommendations for topics requiring further investigation.
Morales, Reinaldo, and Robert Ettema. Insights from Depth Averaged Numerical Simulation of Flow at Bridge Abutments in Compound Channels, MPC-11-237. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2011.