CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

gravity problem.

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 27, 2005, 03:48
Default gravity problem.
  #1
vidhuresh
Guest
 
Posts: n/a
hi i am solving simple one dimensional problem of flow through pipe with velocityinlet and pressure outlet boundary conditions. axis of pipe is x-positive direction.

i could not finding the effect of gravity in solution (pressureplots) when i am activating gravity in opertion condition panel with value9.81.

whether in static pressure plot/ total pressure plot i find efect of gravity.

  Reply With Quote

Old   October 27, 2005, 06:42
Default Re: gravity problem.
  #2
aykut
Guest
 
Posts: n/a
Hi are u making an air flow simulation or something else? Regards
  Reply With Quote

Old   October 28, 2005, 01:14
Default Re: gravity problem.
  #3
vidhuresh
Guest
 
Posts: n/a
hi,

i am simulating with water. i have even changed the sign of gravity as well but no change in result .
  Reply With Quote

Old   October 28, 2005, 12:08
Default Re: gravity problem.
  #4
Matt Frain
Guest
 
Posts: n/a
Try setting the operating density to zero.
  Reply With Quote

Old   October 29, 2005, 21:42
Default Re: gravity problem.
  #5
Matt Frain
Guest
 
Posts: n/a
Some things to consider:

1) If gravity is acting in the -Y direction in this case, gravity will only cause a hydrostatic pressure gradient across the pipe diameter. It will not affect the flow field unless the fluid density varies.

2) If your pipe diameter is small and the fluid is a gas, the hydrostatic pressure gradient will be negligibly small as compared to the pressure gradient due to flow resistance. If this is the case, then you will not see this gradient on a contour plot. The effect you are seeking may be very small compared to other flow gradients.

  Reply With Quote

Old   October 30, 2005, 07:25
Default Re: gravity problem.
  #6
vidhuresh
Guest
 
Posts: n/a
hi mattfrain,

i have checked it again my gravity in x-direction. fluid i am using is water. pipe diameter is 10 cm and lengthis 1m. velocity at inlet is 0.001m/s, pressuer at outlet is 0. if there is any another method please help me .

thanks for your reply.

  Reply With Quote

Old   October 31, 2005, 00:59
Default Re: gravity problem.
  #7
vidhuresh
Guest
 
Posts: n/a
hi matt frain,

you are right. setting operating density to zero is giving results

thanks for your reply

bye-bye
  Reply With Quote

Reply


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
Problem Importing Geometry ProE to CFX fatb0y CFX 3 January 14, 2012 19:42
Two Phase Darcy flow with gravity -> problem Cyp OpenFOAM Programming & Development 0 November 17, 2010 07:58
natural convection problem for a CHT problem Se-Hee CFX 2 June 10, 2007 06:29
Adiabatic and Rotating wall (Convection problem) ParodDav CFX 5 April 29, 2007 19:13
Is this problem well posed? Thomas P. Abraham Main CFD Forum 5 September 8, 1999 14:52


All times are GMT -4. The time now is 00:35.