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Hello dear TELEMAC users,

I am working on a source that can occur (depending on the tides) in dry areas. I noticed that when my simulation starts at low tide (with the source located in a dry area), nothing happens—there is no discharge at all. However, when the simulation begins with the source submerged, it behaves completely normally, even if the sea level later decreases and the source ends up in a dry area. Moreover, when starting at low tide, the source begins functioning as soon as it becomes submerged.

I searched the forum to see if anyone else has encountered this issue but couldn’t find much information. I also tried running my model with different advection schemes and tidal flat treatments, but the problem remains the same.

As a workaround, I’ve managed to bypass the issue by starting the simulation with a constant elevation higher than the source height. While this causes instabilities during the first few hours of the simulation, it eventually converges.

If anyone has any insights or suggestions on how to solve this problem, I’d greatly appreciate your input!

Have a great day,
Thomas

Hello,

Which release do you use?

What is the bottom elevation of the node where you want to put the punctual source? Is it 1.9 m? It is not recommended to put a punctual source on the bottom (bottom should be impervious).
Rather than this feature, you should try OPEN BOUNDARY CONDITIONS ON THE BED and PRESCRIBED FLOWRATES ON THE BED keywords (but not available for tracers).

Chi-Tuan