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Hi all

I’m new to Telemac and I think I’m missing something quite basic when attempting to run a calculation.

My calculation completes and generates a results file (with elevation and depth), however all the U and V results are 0. I’ve set the calculation for 3 time steps of 100 seconds.

The model has 4 ‘sides’ an inlet, an outlet and 2 walls. For boundary conditions the inlet is defined with entities (5 4 4), the outlet is defined with (4 5 5) and the wall is defined as (2 2 2), so from what I understand I need to prescribe two flowrates within Superviser and two depths (i.e. 2 finite values in PRESCRIBED FLOWRATES, 2 values in PRESCRIBED ELEVATIONS with initial conditions CONSTANT ELEVATION).

I’m probably missing something (if not quite a lot of things!) simple, but I can’t see what it might be!

Many thanks in advance
Steve

Hello,

In fact the inlet should be 4 5 5 and the outlet 5 4 4.

Then you have to find which liquid boundary is 1 and which is 2. If your domain is a square or a rectangle, your inlet on the left and your outlet on the right (a basic channel), then boundary 1 is on the right. The prescribed discharge on the left should then be given as the second value in the key-word PRESCRIBED FLOWRATES.

With best regards,

Jean-Michel Hervouet

Thank you very much for your quick reply Jean-Michel! I've now managed to get non-zero values out! It seems that as well as having incorrect boundaries the iteration limit was being reached too easily.

Just to clarify the use of entities, I have defined the entities as you specified below, such that PRESCRIBED FLOWRATES has 2 values (the second of which is the flowrate into the system). As the boundary conditions are (5 4 4) for the outlet then U and V should be free, so the first value (boundary 1) of PRESECRIBED FLOWRATES has no effect?

Similarly the inlet conditions are (4 5 5 - free depth) so that the first value for PRESCRIBED ELEVATIONS has no effect on the system?

Thank you once again
Steve

Yes you are right, if you give a prescribed value for a boundary where the variable is free, it will be just not considered.

Regards, JMH