If you’ve been doing some 2D modeling, you most likely have run into what I call nuisance cell errors. You see them while your model is running and they can really slow down your simulation as the RAS chugs through iterations to try to come to a solution. The errors here are in the […]
You can have a 2D full momentum model without errors if: Your cell size and computation interval is appropriate Everything is moving very slowly Stages are high Slopes are shallow N values are high Discharge doesn’t change too suddenly It’s a 2D only model (i.e. no connections to 1D) You are a skilled HEC-RAS modeler […]
As RAS model development is done more and more through GIS, using the HEC-GeoRAS extension, cross section point filtering is becoming a standard part of the HEC-RAS model development exercise. It’s not too uncommon for a model created in GIS to have multiple hundreds of cross section station elevation points. This is normally not a […]
One of the most frustrating aspects of unsteady HEC-RAS modeling can be the model stabilization process. You know, you’ve gone to great lengths collecting the best survey/topo data and solid hydrology. Then you’ve painstakingly spent hours…possibly days entered all of that data only to find that once you press the “Compute” button, the model crashes. […]
I just received this question about downstream boundaries in HEC-RAS, and thought it would make a nice post here on RASModel.com. “…regarding the boundary condition, if I use critical depth instead of normal depth will it be unacceptable? When choosing the normal depth I need to enter a slope, can i use just one slope […]