Hi,
I’m trying to calculate my model with an unsteady flow analysis.
Upstream, I select the flow hydrograph and downstream the normal depth. When the computes finishes, there isn’t any error but if I take a look to the stage and flow hydrographs, there are a lot of inestabilities with flow and stage. I go to the output tables and, at the begining of the computation, there are negative flows (negative velocities, very high E.G.Slope). The distance between cross sections is about 5-20 m and the slope is around 0.07 m/m.
I’ve tried to adjust all the parameters in the ‘Calculation Option and Tolerances’ table and also I’ve checked the mixed flow option but I can’t get a stable solution.
My next step is to introduce a dam with an inline structure, but in the same model than before, I get this error:
A change (or known value) in WSEL or EG at a node at river station 1120 caused a WSEL below the bottom of the cross section. Check you data at this location for errors.
Subroutine STD_WSCH
Unsteady flow encountered an error
I’ve checked the HTab Param table and the starting Elevation is fixed to the invert with a 0.01 increment and 200 points.
Also, I’ve increment the base flow.
Can anyone help me??? I’ve been a lot of time trying to solve this model but it has been imposible.