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Increase WAQ simulation period than Flow?

Amaal Osama Fathy, modified 4 Months ago.

Increase WAQ simulation period than Flow?

Youngling Posts: 8 Join Date: 11/6/18 Recent Posts

If the Flow simulation period is 2 weeks and resulted that it was not enough for the DO and BOD curves in observation points to be stabilized  according to Steer-Philips equation. Do I have to run the Flow model for longer time or just I need to increase the WAQ simulation period - with same Flow simulation period- ?

Also in general, if I increased the WAQ simulation period than the Flow, will the model re-use the flow cycle starting from the first time-step or it will use the last time-step calculations as constant to be governing? knowing that the flow is steady. 

 

 

AM
Arjen Markus, modified 4 Months ago.

RE: Increase WAQ simulation period than Flow?

Jedi Knight Posts: 235 Join Date: 1/26/11 Recent Posts

WAQ will reuse the hydrodynamic result cyclically if the WAQ simulation period exceeds the FLOW simulation period. That does mean that you have to be a bit careful about the precise period of the hydrodyamic calculation: the start of the (converted) flow field and the end should be close enough, that is end at the same tidal phase, preferrably highwater. Otherwise there would be a large jump in the water volume from the last time in the flow result to the first time, resulting in a mass error. This is corrected for, but still the smaller the correction, the better.