CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > CFX

Acceleration in CFX Post

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 3, 2008, 11:52
Default Acceleration in CFX Post
  #1
LancelotCFD
Guest
 
Posts: n/a
Hi everyone, I am looking for acceleration values in ansys cfx. I have searched in help and in forums but no one seem to know how can you compute and display acceleration chart in Ansys CFX. Any idea ? Thank you for your help .
  Reply With Quote

Old   November 3, 2008, 17:16
Default Re: Acceleration in CFX Post
  #2
CycLone
Guest
 
Posts: n/a
Acceleration of what?

Are you looking for velocity gradients? If that's the case, there are 3 vector variables, Velocity u.Gradient, Velocity v.Gradient and Velocity w.Gradient, which represent the 9 components of the gradient of velocity.

-CycLone
  Reply With Quote

Old   November 4, 2008, 03:45
Default Re: Acceleration in CFX Post
  #3
LancelotCFD
Guest
 
Posts: n/a
Acceleration of fluid . I dare say that velocity gradients and acceleration are not the same fluid. To make it clear, if V is velocity vector I am looking for dV/dt not for grad V or dV/dx ... So anyone has an idea on the subject ?
  Reply With Quote

Old   November 4, 2008, 07:29
Default Re: Acceleration in CFX Post
  #4
Fahim
Guest
 
Posts: n/a
Hi

Are you doing Transient simulation?

  Reply With Quote

Old   November 4, 2008, 09:13
Default Re: Acceleration in CFX Post
  #5
LancelotCFD
Guest
 
Posts: n/a
Yes, I'm pretty sure Ansys solver compute acceleration to solve the Navier stokes equation so why isn't it available? Is there some kind of tricks I should use ? I tried CEL expression but it does not have the derivation operator. I want them in Ansys CFX, rather than in a third party software ... Thanks for your help !
  Reply With Quote

Old   November 4, 2008, 11:42
Default Re: Acceleration in CFX Post
  #6
CycLone
Guest
 
Posts: n/a
The transient term within a cell is not the same as acceleration. Note that since the fluid is moving, the acceleration is actually the dot product of the velocity and gradient (i.e. the gradient in the direction of the flow).

What do you need the "acceleration" for? What are you trying to compute? There is probably another way which you have not considered.

-CycLone
  Reply With Quote

Old   November 4, 2008, 12:06
Default Re: Acceleration in CFX Post
  #7
LancelotCFD
Guest
 
Posts: n/a
All right, you're saying that I can consider the advection as an acceleration ? What I am doing is studying an oscillating flow, normal to a slender cylinder. The main purpose of this is getting an approximation of the added mass coefficient of the cylinder, the base equation being morison's equation.

  Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
CFX Post export problem jeff_F CFX 0 August 17, 2009 21:25
chart for transiente simulation - CFX Post rogbrito CFX 0 June 22, 2009 12:12
CFX Post processing aditya CFX 1 July 6, 2008 12:09
Chart Generation in CFX Post Vadim Baines-Jones CFX 2 August 28, 2007 09:14
Tecplot for CFX post processing pantangi goud CFX 2 August 24, 2005 16:42


All times are GMT -4. The time now is 19:49.