CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > CFX

hydrostatic and static pressure

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   May 25, 2004, 11:56
Default hydrostatic and static pressure
Posts: n/a
Hello, Im simulating a two phase flow. Imagine a bucket with water. The reference pressure is set to zero. As initial condition I set the hydrostatic pressure as the relative static pressure being zero in the interphase and increasing with depth up to 3e6 Pa. When I visualize the initial condition pressure field in Post(static pressure I assume) it is ok and in agreement with the above variation but in the next timestep the pressure field is almost uniform and about 4e6 Pa which makes not much sense. I guess that hydrostatic pressure term is not included, but it was in the initial state? May anyone make me clear how the pressure is dealt by Post?

thanks pi
  Reply With Quote

Old   May 26, 2004, 00:14
Default Re: hydrostatic and static pressure
Posts: n/a

I am not sure which version of software u r using... CFX-5.6/5.7. In case you are using CFX-5.6, the pressure would not include hydrostatic head. there are two work arounds for this problem.

1. For the results create another variable in POst which is Static pressure+hydrostatic head. (since ref press=0)

2.Set the buoyancy reference density=0 in pre. This will include the hydrostatic head in the pressure equation.
  Reply With Quote

Old   May 26, 2004, 09:53
Default Re: hydrostatic and static pressure
Posts: n/a
Hi Test,

Take CFX5.6, why do you reccommend that the bouyancy reference density in Pre be set to zero? Typically, the buoyancy reference density in a two phase system is taken as the density of the continuous phase (at least for the inhomogeneous approach). If you take it as zero, what is the implication of this on drag and body forces that have effect on the over all flow field, pressure, etc?

regards Anne
  Reply With Quote

Old   May 26, 2004, 10:35
Default Re: hydrostatic and static pressure
Posts: n/a
HI, Well this is due to some limitation in the code. I cannot provide you the explanation which I have in a powerpoint presentation to explain this fact. You can contact your local CFX support who should be able to help you out.

  Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Static Pressure & Hydrostatic Pressure Liwau CFX 3 April 16, 2023 12:32
Hydrostatic Pressure and Gravity miliante OpenFOAM Running, Solving & CFD 132 October 7, 2012 22:50
single phase hydrostatic pressure problem erkan FLUENT 1 March 1, 2010 12:29
Hydrostatic pressure gradient Craig Finch (Finch) OpenFOAM Running, Solving & CFD 10 February 28, 2007 23:02
static pressure Benj FLUENT 0 November 29, 2004 10:48

All times are GMT -4. The time now is 18:10.