Accession Number : ADA311243

Title :   A Two-Dimensional Free-Surface Flow Model for Trapezoidal High-Velocity Channels.

Descriptive Note : Final rept.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS HYDRAULICS LAB

Personal Author(s) : Stockstill, Richard L.

PDF Url : ADA311243

Report Date : JUN 1996

Pagination or Media Count : 200

Abstract : A two-dimensional free-surface numerical flow model for trapezoidal high-velocity channels is developed. The model addresses common hydraulic features of high-velocity channels including subcritical or supercritical flow, which may undergo transition from one regime to the other and can be further complicated by the presence of oblique standing waves. The model is designed specifically for simulation of flow in trapezoidal high-velocity channels in which the depth is an unknown variable in the governing equations; therefore, the plan view of the flow domain as delineated by the water surface/bank interface is not known a priori. Steady state solutions are obtained by time-stepping from specified initial conditions using an implicit Petrov-Galerkin moving finite element representation of the governing equations. As the computed flow field evolves from the specified initial flow conditions and initial boundary location to the steady state, the moving finite element model adjusts the location of side boundaries with the depth solution. The algorithm includes a novel method for solving the boundary displacement and the flow variables simultaneously. Testing of the computational model consists of comparing model results with analytical solutions and laboratory flume data. These tests demonstrate that the numerical model can be used as a tool for the evaluation of trapezoidal high-velocity channel designs.

Descriptors :   *WATER FLOW, *CHANNELS(WATERWAYS), *FLOOD CONTROL, MATHEMATICAL MODELS, ALGORITHMS, COMPUTERIZED SIMULATION, STEADY STATE, HIGH VELOCITY, FINITE ELEMENT ANALYSIS, DISPLACEMENT, TURBULENT FLOW, SHALLOW WATER, FLOW FIELDS, PARTIAL DIFFERENTIAL EQUATIONS, SUPERCRITICAL FLOW, NONLINEAR ANALYSIS, TWO DIMENSIONAL FLOW, NUMERICAL METHODS AND PROCEDURES, ELEVATION, BANKS(WATERWAYS), HYDRAULICS, VISCOSITY, STREAMFLOW ANALYSIS, LEVEES, DOWNSTREAM FLOW, BOUNDARY LAYER FLOW, STANDING WAVES.

Subject Categories : Hydrology, Limnology and Potamology
      Civil Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE