SOLUTION SOLVER FAILED! Unstable for Initial Iteration at 31JUL2010 2400

[Anonymous]

Dear Sir Chris Goodell

I am doing MS in Remote Sensing and GIS from National University of science and technology Islamabad Pakistan.
My focus of research is 2010 flooding in Sindh Province Pakistan. My topic of research is “Flood inundation in northern Sind during floods 2010 and siting of Safe Haven : A Case Study of Levee Breach Induced Catastrophic Flooding”
I have been working on this research for the last one and a half year, although I am able to run steady flow with split flow optimization on lateral structure. But I am facing problem in running unsteady flow analysis. Getting the following error

Error
Geometric Preprocessor Version 4.1.0 Jan 2010

Finished Processing Geometry

Performing Unsteady Flow Simulation Version 4.1.0 Jan 2010

SOLUTION SOLVER FAILED! Unstable for Initial Iteration at 31JUL2010 2400

Finished Unsteady Flow Simulation

Writing Results to DSS
Finished Writing Results to DSS

Task Time
Preprocessing Geometry 3.21 sec
Unsteady Flow Computations 6.18 sec
Writing to DSS 2.28 sec
Complete Process 11.70 sec
Computation messages written to: C:\HECGEoRAsWork\June\June10.p04.comp_msgs.txt

Please help me

Thanks in anticpation

Regards.

[cameron]

The model is crashing based on your initial conditions. You set these in the unsteady flow data editor in the initial conditions tab. Generally the initial conditions should be set so they match the flow of your inflow hydrograph.

If you are still having problems after this, you can try a ramp up or hotstart to help stay stable.

[Ahmed Adel]

please check these online resources

*- Common Model Stability Problems When Performing an Unsteady Flow Analysis
*- Investigating Instabilities with HEC-RAS Unsteady Flow Modeling for Regulated Rivers at Low Flow Stages

[Author]

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