Fluid Flow (Waterhammer or Pressure Surge)

[tibor121774]

Hi all!!! Is simulation cfd also capable of fluid flow analysis due to waterhammer or pressure surge?...Many Thanks...

[Royce_adsk · Accepted solution]

Yes we do!

http://help.autodesk.com/view/SCDSE/2014/ENU/?guid=GUID-3258D265-9C18-4CCC-A79C-84ADBD2B0B3D

[tibor121774]

Thanks Royce for the response...Can it also generate some sort of forces due to waterhammer as an input to a mechanical software such as Autopipe or Caesar for Dynamic Analysis (time history type) analysis?....Many thanks...

.

[koltekmusavirlik]

How is it exactly we can make this analysis? Currently I am trying to do it for a pump system. Pump station pumping at 3,35 m3/s water in a pipe. And if the pump stops suddenly water hammer effect occurs how can I analyze this?

[Jon.Wilde]

Hi,

It is probably best to start a new thread for this as this one was marked as solved and I at least tend to look over those.

You could do this with a transient compressible analysis though. Get your model ready first - is it just a pipe?

Could you run it as a 2D axisymmetric model? 

Thanks,

Jon

[koltekmusavirlik]

It starts with a pump. I will give you layout of what I am trying to achieve on the picture down below which I created on Civil 3d

[Jon.Wilde]

I see. Do you need to model the pump though? Not sure if just specifying an inlet flow rate on a pipe might be sufficient?

(This is much easier than modelling a spinning pump 🙂 )

[koltekmusavirlik]

What I try to find is in case this pump stops working suddenly how the water will react to this and what kind of pressures will occur inside steel pipe. Like vortexes etc...

[Jon.Wilde]

Your call then really. On the face of it - I would guess you do not need to model the pump.

Do you think that assigning an inlet flowrate that suddenly drops to near zero would give you what you need?

[koltekmusavirlik]

Yes something like this. But how can I reduce this flow rate to 0 suddenly are there timed conditions? Also outlet flow rate should become 0 aswell at that second. and the only thing pushing water upside should be its own momentum which will become 0 in mere seconds after flow rate becomes 0 due no pushing force.

So how can I do this? It sounds pretty easy when I say it like that but oh well 🙂

[Jon.Wilde]

That is because it is 🙂

You would assign transient boundary conditions. Have you run through the tutorial models already?

They are a good basic starting point: CFD 2016 Tutorials