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Dear Friends,

I need to simulate a steady flow simulation. let's say my inflow discharge is 1 litre/sec for a duration of one hour. So in this case, Do I need to prepare a 'liquid boundaries file' or simply prescribed flow rate is enough? And also, Does the prescribed flow rate correspond to inflow only? or it can be for outflow also?

If I want to have a constant depth at the inflow and outflow, Is it OK to give the prescribed elevation only? or something else is required.

Similarly, Is the prescribes velocity mandatory or not?

Kind regards,
Saroj

Dear Saroj,

1)Liquid boundary files are mostly used when you are on unsteady state simulations, prescribed flow rate is enough. But you could achieve a steady state in liquid using a constant value using 2 time steps (s) e.g. 0 [your flow] ; 9999999 [your flow].

2)Usually, a well posed river case is approached using prescribed flow rate in your "inlet(s)" boundary (ies) conditions and a prescribed elevation in the "outlet(s)" one>(s). The equivalent in unsteady cases are Liquid boundary files and stage-discharge curves respectively. You *Could* prescribe an outflow though, this tends to lead to some instabilities along the simulation.

3)Yes you can have your prescribed elevation/discharge but usually what I do is to "pre-calibrate" the model (cold-start simulation) to achieve my desired Inflow-elevation using only prescribed flow values, generating a "Hotstart" file which will be used as a initial condition for my "main" model.

4)Prescribed velocities are not mandatory but you should prescribe the velocity profile. Telemac2D is a depth averaged solver suite.

Hope it helps somehow. Regards,

José D.