Critical depth is an important hydraulic parameter when evaluating hydraulic modeling results. As we know from our college hydraulics 101 class, water flowing at depths less than critical depth is supercritical and water flowing at depths greater than critical depth is subcritical. Supercritical flow is characterized by relatively shallow depths and high velocities. Subcritical flow […]
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. […]
By using the Mixed Flow Regime option for Unsteady Flow Analysis, RAS can better handle transitions from subcritical to supercritical flow. This option should be utilized only after determining that a mixed flow situation exists, which requires judgment from the modeler. One application where this could be particularly useful is dam breach modeling, or any […]