One of the most anticipated new features soon to come in the next major version of HEC-RAS (Version 5.1) is the option of running unsteady 1D reaches with a finite volume solution scheme. This will be a fantastic addition to HEC-RAS. Gary Brunner recently gave me a brief overview of the new finite volume feature […]
Situation: Advances in HEC-RAS now allow for improved simulation of overbanks using 2D Flow Areas. Coupled 1D/2D models where 1D cross-sections represent the bank-to-bank cross-section data and 2D flow areas represent overbank areas has greatly improved the accuracy and robustness of HEC-RAS models. This is particularly the case in flat, urban areas with significant overbank […]
Suppose you have two separate HEC-RAS rivers and wish to combine them. There is no “combine two rivers” option in HEC-RAS, but it can be done using the Move Points/Objects option. Take the very simple reach presented below: I wish to combine the Upper Tualatin with the Clackamas reach of the Willamette River. In the […]
In the current version of HEC-RAS (v 4.1.0) there are two methods of modeling the hydraulics at a junction for unsteady flow. By default RAS selects the Force Equal WS Elevations (Forced) method, which forces the upstream bounding cross-sections’ water surface equal to the downstream water surface. This method may be adequate for some situations […]