Lateral structures can be used in HEC-RAS to transfer flow from a river/reach to a storage area, or to another river/reach. With the coming release of HEC-RAS with 2D capabilities (estimated beta release January/February 2014), you’ll be able to hook a river/reach to a 2-D area using a lateral structure. Although its primary function in […]
Though it’s not very common, it is possible to get negative flows over inline structures for unsteady flow simulations. It’s much more likely you’ll see negative flows over a lateral structure though. Negative flows are simply discharges in your model going the opposite direction than what you have defined as the downstream direction (or primary […]
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 […]