Increase WAQ simulation period than Flow? - Home - Delft3D
Increase WAQ simulation period than Flow?
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.
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.