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## Simulation CFD

Valued Contributor
Posts: 97
Registered: ‎02-08-2011

# Water Column, Static Pressure Study

200 Views, 11 Replies
05-13-2013 04:25 AM

Hi to all,

here a video i made  to describe it for you (static pressure in a 10 m water column)

Where i wrong?

Thanks for suppport,

Pompeo

*Expert Elite*
Posts: 437
Registered: ‎10-02-2012

# Re: Water Column, Static Pressure Study

05-13-2013 11:55 AM in reply to: pompeo79

Video is not available!

OJ

Valued Contributor
Posts: 97
Registered: ‎02-08-2011

# Re: Water Column, Static Pressure Study

05-13-2013 01:37 PM in reply to: pompeo79

The video works fine now. I think it was a youtube issue.

Tell me if it's ok for you guys too.

Valued Contributor
Posts: 97
Registered: ‎02-08-2011

# Re: Water Column, Static Pressure Study

05-14-2013 02:35 AM in reply to: pompeo79

If the previous video won't work, try with this one, more stable:

Valued Contributor
Posts: 97
Registered: ‎02-08-2011

# Re: Water Column, Static Pressure Study

05-14-2013 06:47 AM in reply to: pompeo79

The pressure at the bottom of a 10 m water column would be 100 Kpa

With the simulation i obtain 164 Pa for the bottom of the column.

Any ideas?

For considering gravity force i have set : SOLVE > Physics>Heat Transfer>Gravity Direction 0,0,1

Active Member
Posts: 8
Registered: ‎08-12-2012

# Re: Water Column, Static Pressure Study

05-14-2013 09:36 PM in reply to: pompeo79

Try ... Gravity Direction 0,0,-1

Valued Contributor
Posts: 97
Registered: ‎02-08-2011

# Re: Water Column, Static Pressure Study

05-15-2013 01:08 AM in reply to: pompeo79

same distribuition..but reversed...same maximum of 164 Pa.

Valued Contributor
Posts: 97
Registered: ‎02-08-2011

# Re: Water Column, Static Pressure Study

05-17-2013 05:31 AM in reply to: pompeo79

No one?

In other word...is it possibile with cfd simulation do a hydrostatic study of pressures in a simple water column?!

Product Support
Posts: 626
Registered: ‎08-24-2011

# Re: Water Column, Static Pressure Study

05-17-2013 06:14 AM in reply to: pompeo79

The quick answer to that is that we aren't traditinally setup to do hydrostatics.  When we introduced the free surface modeling in 2014, that does include hydrostatics so you could try using that.

Also, try turning on the total pressure result, I think that does give you the hydrostatic pressure result.

-Royce

Royce Abel
*Expert Elite*
Posts: 437
Registered: ‎10-02-2012

# Re: Water Column, Static Pressure Study

05-17-2013 07:57 AM in reply to: pompeo79

I have a bad experience with hydrostatic flows, at least for SimCFD 2013. But for some reason, I believe that this dodgyness in results is our inability to set the right boundary condition for top surface of the water column.

I hope that 2014, with the free surface BC, the top surface has now an adequate representation, and will come down in a more natural and realistic manner, as the water in the column is released from the bottom. This doesn't happen now with 2013 and perhaps solver struggles to find peace with the mass conservation.

OJ