Learning Forum

[walaakm10]

Hello every one.

I have an inquiry, I get confused about the water inlet in my cases study. In the geometry i stated the inlet boundary condition height as 0.1m and width as 1 m, does this mean that the water height is constant and equals to 0.1m during the whole simulation? 

The real case that I am simulating dosen't have a constant 0.1m height, but the height should be increasing from 0 to 0.1m during the simulation.

SO, if my geometry has 0.1 m inlet heigh, will this be correct or not? 

and if it is not correct, how to simulate changable water inlet height from 0 to 0.1 during the simulation time?

 

Thanks in advance

[Rob]

If you set something in the geometry it's fixed unless you're using deforming mesh. If you're wanting to vary the free surface in the VOF Open Channel, have a look at the available options. If you want something else please sketch out what you're doing as it's not clear from the above. 

[walaakm10]

thanks for your reply,

 

Okay, the case is that for this inlet (h), I draw it in geometry equal to 0.1m, but this is not the true case. 

The true case is that there is a flood height of h, which increases from 0 to h along the simulation time (from time 0 to 30 minutes, for example). 

 

From manual calculations for the flood at the inlet at each second, I know what the h and the velocity will be.

 

So, what will be the best simulation for this inlet?

[Rob]

Open channel, you need to set that in both the Multiphase VOF panel and the inlet boundary condition panel. Be careful with position and depth settings to ensure you define these correctly. Note, I'd advise against a zero area inlet and start with some water entering the domain. Also read up on the VOF model as you're going to need a lot of mesh to resolve the flow and free surface.