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

Error in Drag Coefficient for 3D sphere

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 7, 2016, 09:22
Default Error in Drag Coefficient for 3D sphere
  #1
New Member
 
Pranjal Seth
Join Date: Jun 2016
Posts: 17
Rep Power: 10
scyllakeeper is on a distinguished road
I am analysing flow around a 3D sphere, for non-Newtonian power law fluids.
I am supposed to study the drag coefficient for various Reynolds numbers.
However, I am getting ambiguous values.

I tried the process for Newtonian fluids as well, but I'm facing the same problem there as well.
For eg., Cd for Re 30 should be around 2 for spheres, but I'm getting close to 9.

Any idea what could be going wrong?
Following are the details.

Sphere has diameter d, and is placed centrally in a cylindrical domain having dia 15d, and length 66d.
For the geometry, I made the sphere using Primitives. Froze it.
Created a circle, and it extruded to get the cylinder.
I generated the geometry, and then cut out the sphere using Body Operation.
I generated the mess, and followed Fluent solver.
Model is Viscous (laminar).
The reference values are being computed from the inlet, and Area is the (pi)(d*d)/4.

Now, this entire thing I've tried for various residuals, various fluids, and various Reynolds numbers. But my results are always wrong.

Any clue what could be happening?
scyllakeeper is offline   Reply With Quote

Reply

Tags
drag coefficients, error, fluent, non newtonian power law, sphere


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
wrong SU2 calculation for lift and drag coefficient for NAC4421 mechy SU2 7 January 9, 2017 06:18
Calculation of Drag Coefficient, Help Please teek22 CFX 1 April 26, 2012 19:41
Drag coefficient for a sphere Nico A. OpenFOAM Running, Solving & CFD 0 July 5, 2011 13:21
Automotive test case vinz OpenFOAM Running, Solving & CFD 98 October 27, 2008 09:43
meshing F1 front wing Steve FLUENT 0 April 17, 2003 13:37


All times are GMT -4. The time now is 23:55.