Learning Forum

[subhamcfd]

I am simulating a 2D hydraulic jump in a rectangular 2d channel. I have a tail-gate at the outlet such that the flow get obstructed by the gate and in due course of time, the water flows over the gate. But , as of now, i have to run the calculations considering fixed height of tail gate and as such , during the calculation , i can not alter the height of tail-gate . As a result , my depths of flow pre-jump and post jump can not be altered and the location of jump also can not be altered.

I intend to create a UDF , so that i can interrupt the calculation after certain iterations and alter the height of tail gate i.e lower or raise the tail gate. I expect the solver to consider this effect upon resuming the calculation.

Is it possible to compile such an UDF? Or is there any simpler process to achieve the above task.

[Rob]

Do you want to model the gate in motion or just have a sudden change in height? You also need a lot more mesh if you want to resolve the free surface.

[Amine Ben Hadj Ali]

Is the tail gate modeled as a wall? Or Pressure Outlet?

[subhamcfd]

Mr. Rob , I want to model the gate such that , i would be able to lower or raise the tail gate (basically a wall) at any time within the solution. Of course , I will interrupt the solution and then raise the gate and resume the solution like in any physical experiment.
Mr. DrAmine , tail gate is modelled as a wall.

[Rob]

I assume this is transient. In that case you could also split the mesh or relabel a zone(s). To do this accurately you'd need to pre-plan the positions to then split the mesh afterwards.