Temperature in HD and WQ - Home - Delft3D
Temperature in HD and WQ
I've a question relating to difference between temperature as a process in
hydro module and water temperature as a substance in delwaq module. what is the difference
and which is preferred to use?
I also need to know about the downstream boundary in WQ module. Is it right that my
model does not follow the d.s. boundary concentrations and I change the concentrations within the
domain myself to achieve the boundary characteristics or something might be wrong?
thanks in advance!
The preference for modelling temperature in Delft3D-FLOW or Delft3D-WAQ really depends on why you need it:
- Delft3D-WAQ does not take the interaction with the flow field into account, such as stratification and density driven flows - as it does not calculate the flow field. FLOW does do that.
- Delft3D-WAQ can either calculate the temperature as a substance or it can import the temperature results from Delft3D-FLOW. The water temperature is a factor in many water quality processes, so it may be of importance indeed.
- The modelling of temperature in Delft3D-WAQ is fairly simple (at least as far as the basic implementation is concerned). Anything more sophisticated probably is best done via Delft3D-FLOW. The basic implementation is meant for such things as the temperature differences due to thermal pollution, not so much the warming and cooling of a water body under influence of the meteorology (a more sophisticated module exists but is not documented, unfortunately)
As for downstream boundary conditions: the equations solved by Delft3D-WAQ are such that these play a minor role only. You can even turn off the influence by setting the dispersion on the boundaries to zero. This is useful because the influence is limited to upstream diffusion/dispersion. Note: this is quite different from hydrodynamic modelling.
Thanks Arjen for your reply, that's was very helpful. So If the temperature is modeled in FLOW module, the output of substances in Delft3D-WAQ will be affected or should I use the Water Temperature as an input substance in PLCT ?
If you want to pick up the temperature as calculated by the FLOW module, then it should be a segment function in Delft3D-WAQ, so indeed a process parameter and not a substance.
thanks Arjen for your time and effort. But I think you didn't get me well. My point is; I need to study the effect of temperature on WQ substances not to pick up the temperature itself. The Temperature is simulated on FLOW module and I need to import it to WAQ input file. Does the online coupling do that or there's another step that I should make?
The coupling from FLOW should produce a .tem-file together with the hyd-file. In the old user interface you will have to pick that up manually. So in the PLCT you will need to set the 'Temp' that is input for many processes to an editable parameter (you only need to do that for one of these processes, they will then all see it as an editable parameter).
In the old user interface, then go to the process parameters, click in the field for Temp, end press the Edit Data button. In Properties - Details, switch to Scalar Field. After that, go to Data - Import. Switch the file type to Delft3D-WAQ segment function, and select the .tem-file. You can do the same with salinity and bottom sheer stress if you need that from FLOW as well.