CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLOW-3D

theta volocity in cylindrical coordinate

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 18, 2010, 22:35
Default theta volocity in cylindrical coordinate
  #1
New Member
 
wuyu
Join Date: Mar 2010
Posts: 20
Rep Power: 6
seasoul is on a distinguished road
I am modeling a fluid impact on a cylinder. Therefore I set it in the cylindrical coordinate. The veloctiy at impact will be resolved into two components, radial and azimuthal velocity. Let's say velocity is 1 m/s, the fluid impacts on the cylinder, not through the circle center. Assume the angle is 30 degrees, the diameter of the cylinder is 1mm. Then the radial velocity is 0.86m/s, the azimuthal velocity is sin30/0.0005=10000 rad/s. But I found the fluid flew away from the computational domain within a quite short time. But physically it should impact on the cylinder. Is the velocity in y direction (theta) in a unit of radian/s?
seasoul is offline   Reply With Quote

Old   October 23, 2010, 15:07
Default
  #2
Senior Member
 
michael barkhudarov
Join Date: Mar 2009
Posts: 329
Rep Power: 8
MuxaB is on a distinguished road
I can't quite picture this in cylindrical coordinates. Where are you setting the inlet velocity?

Why not do it in a Cartesian grid?

Quote:
Originally Posted by seasoul View Post
I am modeling a fluid impact on a cylinder. Therefore I set it in the cylindrical coordinate. The veloctiy at impact will be resolved into two components, radial and azimuthal velocity. Let's say velocity is 1 m/s, the fluid impacts on the cylinder, not through the circle center. Assume the angle is 30 degrees, the diameter of the cylinder is 1mm. Then the radial velocity is 0.86m/s, the azimuthal velocity is sin30/0.0005=10000 rad/s. But I found the fluid flew away from the computational domain within a quite short time. But physically it should impact on the cylinder. Is the velocity in y direction (theta) in a unit of radian/s?
MuxaB is offline   Reply With Quote

Old   October 31, 2010, 05:02
Default
  #3
New Member
 
wuyu
Join Date: Mar 2010
Posts: 20
Rep Power: 6
seasoul is on a distinguished road
I am actually modeling a droplet, so there is no inlet velocity issue. And I want to postprocess the data close to the cylinder surface, if in cartesian coordinate, is it possible to create a slice parallel to the curvature surface?
seasoul is offline   Reply With Quote

Old   November 1, 2010, 00:49
Default
  #4
Senior Member
 
michael barkhudarov
Join Date: Mar 2009
Posts: 329
Rep Power: 8
MuxaB is on a distinguished road
Quote:
Originally Posted by seasoul View Post
I am actually modeling a droplet, so there is no inlet velocity issue. And I want to postprocess the data close to the cylinder surface, if in cartesian coordinate, is it possible to create a slice parallel to the curvature surface?
Yes, that what an 2D plot in an y-z plane in the Analyze tab would do.

If you are trying to define an initial uniform droplet velocity moving towards the cylindrical axis, I don't think you can do it using the available input in FLOW-3D (if understand your problem). It is much easier in a Cartesian grid.
MuxaB is offline   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
cylindrical coordinate vs cartesian coordinate Lam FLUENT 10 May 11, 2013 13:05
cylindrical coordinate -Gambit noussa ANSYS Meshing & Geometry 2 June 12, 2010 09:07
CFD Software with Cylindrical and Spherical Coordinate cfd2010 Main CFD Forum 0 June 9, 2010 21:55
Star-CD Cylindrical coordinate hamoudi STAR-CD 4 April 29, 2009 11:11
Cording Ground.for in Cylindrical coordinate J.H. Lee. Phoenics 2 March 28, 2003 04:28


All times are GMT -4. The time now is 06:23.