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Forum: OpenFOAM Running, Solving & CFD January 2, 2008, 20:24
Replies: 41
Views: 10,732
Posted By andrewburns
paraView keeps crashing when I

paraView keeps crashing when I try to make an animation of my solution, so here are two pics instead.

The first is the velocity field around the cylinder, the second are vector glyphs of the...
Forum: OpenFOAM Running, Solving & CFD January 2, 2008, 17:22
Replies: 41
Views: 10,732
Posted By andrewburns
Ok so I'm back from holiday an

Ok so I'm back from holiday and while I was gone I ran my Re = 500k cylinder for 6000 iterations.

The forces I came back to are:

Pressure Force = 0.681694
Viscous Force = 0.0104461 ...
Forum: OpenFOAM Running, Solving & CFD December 20, 2007, 18:38
Replies: 41
Views: 10,732
Posted By andrewburns
Currently (running stable) I h

Currently (running stable) I have 3 non-orthagonal correctors and my time step continuities are:

sum local = 1.08838e-08
global = -6.28549e-10
cumulative = 2.52733e-08

Solution looks...
Forum: OpenFOAM Running, Solving & CFD December 20, 2007, 18:06
Replies: 41
Views: 10,732
Posted By andrewburns
I think someone took the liftD

I think someone took the liftDrag equations and integrated them into the solver rather them being a separate routine. I don't have the separate liftDrag utility properly installed so it can't be...
Forum: OpenFOAM Running, Solving & CFD December 20, 2007, 17:35
Replies: 41
Views: 10,732
Posted By andrewburns
Just checking in to say my Re

Just checking in to say my Re = 500000 case is coming along smoothly. I initialised the solution with potentialFoam then started it in ssimplefoam with a laminar turbulence model. After 100...
Forum: OpenFOAM Running, Solving & CFD December 19, 2007, 18:02
Replies: 41
Views: 10,732
Posted By andrewburns
Thanks for the suggestion, I d

Thanks for the suggestion, I didn't know you could isolate patches in paraview. I just checked and the top and bottom faces of the boundary are 'inlets' while the end (which is supposed to be the...
Forum: OpenFOAM Running, Solving & CFD December 19, 2007, 17:39
Replies: 41
Views: 10,732
Posted By andrewburns
Hmm I changed my mesh to be mo

Hmm I changed my mesh to be more detailed in the entrance and wake regions in front and behind the cylinder and somehow my simulation ended up looking like this (can you spot the problem).
...
Forum: OpenFOAM Running, Solving & CFD December 18, 2007, 17:05
Replies: 41
Views: 10,732
Posted By andrewburns
I've just started it with k-ep

I've just started it with k-epsilon, I don't really know enough about running other turbulence models and I'm limited to those supported by the ssimplefoam solver, until I can get the liftdrag...
Forum: OpenFOAM Running, Solving & CFD December 18, 2007, 16:37
Replies: 41
Views: 10,732
Posted By andrewburns
Thankyou. I'm going to try the

Thankyou. I'm going to try the same mesh with an Re of 500000 today to see if I can validate for turbulent flow (Cd should be around 0.3). I may have to refine the boundary layer cells more however...
Forum: OpenFOAM Running, Solving & CFD December 17, 2007, 22:48
Replies: 41
Views: 10,732
Posted By andrewburns
Here are images of the new mes

Here are images of the new mesh if you're interested. It was made with gmsh using un-structured prisms, obviously I'd much rather a hex mesh around the cylinder but I don't know if gmsh is capable of...
Forum: OpenFOAM Running, Solving & CFD December 17, 2007, 22:15
Replies: 41
Views: 10,732
Posted By andrewburns
Thanks for the advice, I re-ra

Thanks for the advice, I re-ran the simulation for Re = 50 while tightening up the mesh quite significantly around the surface of the cylinder. I ran the simulation until all the momentum residuals...
Forum: OpenFOAM Running, Solving & CFD December 17, 2007, 19:17
Replies: 41
Views: 10,732
Posted By andrewburns
I just tried the cylinder with

I just tried the cylinder with an Re = 50, this Reynolds number should be too low for vortex shedding so a steady state solution should do, Cd should be around 1.5.

I'm getting a Cd of 0.68...
Forum: OpenFOAM Running, Solving & CFD December 17, 2007, 16:47
Replies: 41
Views: 10,732
Posted By andrewburns
Srinath, did you get a chance

Srinath, did you get a chance to look at the case I sent to you? I sent it to your gmail.
Forum: OpenFOAM Running, Solving & CFD December 14, 2007, 05:55
Replies: 41
Views: 10,732
Posted By andrewburns
Srinath Madhavan, I'll pack up

Srinath Madhavan, I'll pack up the case and send it to you tomorrow when I'm back at work, thanks for the help.

Currently I'm trying the simplefoam case because the only solver I have that...
Forum: OpenFOAM Running, Solving & CFD December 14, 2007, 00:06
Replies: 41
Views: 10,732
Posted By andrewburns
http://www.cfd-online.com/Open

http://www.cfd-online.com/OpenFOAM_Discus/messages/1/5067.html

About half way down that page.

I used the same mesh and increased Re to approx 500000 and ended up with a Cd of around 0.9,...
Forum: OpenFOAM Running, Solving & CFD December 13, 2007, 22:03
Replies: 41
Views: 10,732
Posted By andrewburns
Sorry I meant the Cd is too sm

Sorry I meant the Cd is too small, not high.
Forum: OpenFOAM Running, Solving & CFD December 13, 2007, 22:02
Replies: 41
Views: 10,732
Posted By andrewburns
Still getting a Cd that's too

Still getting a Cd that's too high, approximately 0.75.
Forum: OpenFOAM Running, Solving & CFD December 13, 2007, 20:32
Replies: 41
Views: 10,732
Posted By andrewburns
Previously the Z planes toward

Previously the Z planes towards and away from me were set as symmetryplane.

I've now set them to empty and I reduced the height of my mesh to 10% of the cylinder diameter and I'm re-running the...
Forum: OpenFOAM Running, Solving & CFD December 13, 2007, 20:12
Replies: 41
Views: 10,732
Posted By andrewburns
The current cylinder depth is

The current cylinder depth is 100% cylinder diameter, so yes the aspect ratio is fairly far off close into the cylinder. However yesterday I accidently tried running with a mesh thickness 1% of the...
Forum: OpenFOAM Running, Solving & CFD December 13, 2007, 18:17
Replies: 41
Views: 10,732
Posted By andrewburns
I've recently been trying to v

I've recently been trying to verify the force outputs of the 'ssimpleFoam' solver I got from another thread on this forum, it's essentially the simpleFoam solver which computes and outputs forces in...
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