Then, this is a numerical model usually applied for the simulation of rivers and channels, where this condition is approximately verified. According to the hypothesis, the accuracy of the solution will be as better as the longitudinal dimension is greater than the other two dimensions.
HEC RAS TUTORIAL EXAMPLE PROJECT FREE
Then, as the Navier-Stokes equations, the equations gives values of velocity and depths and therefore leads to hydrodynamic models that study the movement of the free surface water through the physic features of the bottom and the sources and sinks.
These one-dimensional equations are usually known as the Saint-Venant equations.
HEC RAS TUTORIAL EXAMPLE PROJECT SOFTWARE
The software has a computational program that solves (through a finite difference method) the simplification of these equations after they are integrated both in depth and width. Equations and calculation procedure The Navier-Stokes equations that rule the behaviour of the fluids are formed by the mass conservation equation (divergence free condition) and the momentum conservation equations (derived from the Newtons second law particularized for flows). The version can be downloaded from the internet in the HEC-RAS website, which is: 2. On the other hand, only the hydrodynamics will be evaluated here. The version 3.1.3 (of May 2005) will be used because no problems have been detected with their use. Below, the Water Quality Data window where this information is included can be seen: Therefore, values of temperature (T), dissolved oxygen (DO), carbonaceous BOD, organic nitrogen, ammonium nitrogen (N-NH4), nitrite nitrogen (N-NO2), nitrate nitrogen (N-NO3), nutrient parameters (atmospheric reaeration,), meteorology data and more information is necessary together an initial condition of all the calculation variables. The last one (version 4.1) is the first that incorporate a water quality module. As usual, there are some versions of the software because it is updated by the authors permanently improving its features. The program has been so accepted that it is used in civil engineering projects nowadays.
This program evolved from the known HEC-2 incorporating a few improvements, such as the graphic interface, or the possibility of exchanging data with the Geographic Information System ArcGIS through Hec-GeoRAS. Introduction HEC-RAS (Hydrologic Engineering Centers River Analysis System) is public domain software which was developed by the Hydrologic Engineering Center of the U.S. HEC-RAS tutorial Index 11.-Introduction.1 12.-Equations and calculation procedure2 13.-Program features.3 14.-Practical example so as to simulate a river.4 15.-Same example with known downstream boundary conditions15 16.-Same example with more spatial discretization20 17.-Same example with an unsteady simulation of the river24 18.-Same example with a bridge.27 19.-Same example with different Mannings values37 1.
Hctor Garca Rbade Subject: COMPUTATIONAL FLUID DYNAMICS I Written in October 2012 Universidade da Corua Master in Water Engineering