open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi there,

I am also trying to model a weir and facing instability issues. The weir I am modelling is generally submerged and the aim is for it to act a flow rate choke (fixed head) in a channel under tidal forcing. It seems that the free surface at the boundary nodes of the weir is unrealistic (up to 1 m of difference) in relation to the surrounding nodes which is leading to instabilities a few hours into my simulation

Not being able to work out the cause of this issue I am currently testing a case where I only being discharging over weir after the model has 'spun-up'. Im not sure if anybody has experienced these issues in the past.