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Hello everyone,

I have a question regarding the use of a single set of boundary condition nodes for a wide range of discharge values through a given river reach. The goal is to run a batch of river simulations by changing only the prescribed discharge value at the upstream end of the domain, with a fixed water surface elevation downstream, and ending the simulation once a steady-state is reached.

Below are some screenshots of the current flow characteristics at low flow, high flow and their current corresponding boundary condition nodes. Unfortunately, for the low flow scenario, the upstream discharge isn't focused only in the main channel, but is also coming from areas of higher bathymetry.

How can I make the upstream discharge BC representative for all flows within the range and ensure that the flow is focused only in the main channel?

Any suggestions would be much appreciated.

Best regards,

Chris

Below are some of the Keywords I'm currently using for your reference:

Tidal Flats = True
Velocity Profiles = 4
PRESCRIBED FLOWRATES =3050;0
PRESCRIBED ELEVATIONS =0;-5
INITIAL ELEVATION =-5
INITIAL CONDITIONS ='CONSTANT ELEVATION'
TYPE OF ADVECTION =1;5
SOLVER =2

After referring to the topic/post [url=http://http://www.opentelemac.org/index.php?option=com_kunena&view=topic&catid=16&id=3957&Itemid=177&limitstart=8]#5149[/url], I believe I've found an answer. Liquid boundary conditions with dry elements can be represented using Velocity Profile = 5.

From my understanding, this velocity profile option calculates the velocity norm magnitude as being proportional to the square root of the depth; where the previous time step depth, is taken relative to the minimum Free Surface Elevation found on the upstream liquid boundary condition (prescribed flowrate in my case). This tends to focus the discharge within the main channel as the attached figures show.

Is my understanding of this velocity profile correct?

Thank you,

Chris