I have just given a run a run on unsteady flow.But after few minutes of simulation,the calculation just stopped & unsteady flow simulation bar color turns blue to red.A error message is just shown noting that–“SOLUTION SOLVER FAILED! Unstable for Initial Iteration at 31DEC1997 2400”,How this problem can be solved?
I have just given a run a run on unsteady flow.But after few minutes of simulation,the calculation just stopped & unsteady flow simulation bar color turns blue to red.A error message is just shown noting that–“SOLUTION SOLVER FAILED! Unstable for Initial Iteration at 31DEC1997 2400”,How this problem can be solved?
More than likely initial conditions are flawed. Check initial flows, basin starting wsel etc to start with. If your inflow hydrographs start with no flow you’ll want to set a “min flow” on the upper most one and have the same flow on the initial conditions page for each reach. I will usually plot the profile for initial conditions. If it looks good it’s usually where I have a basin coming in and the starting wse if significantly different than the receiving stream, setting the basin close to stream initial wse usually fixes it. Pilot channels also help to greatly improve initial conditions. Theres a lot of other things that could be going wrong though too.