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windhair June 19, 2001 06:46

Anyone use CFDRC?
 
Is there anyone who use CFDRC software as a CFD tools?

Alton J. Reich June 19, 2001 09:40

Re: Anyone use CFDRC?
 
I work for CFDRC as an applications engineer and have used our software for everything from micro-mirrors and ink jet printers to the sloshing of oil in storage tanks due to earthquake loads.

Let me know what you're interested in. Chances are that either I, or one of the folks I work with has simulated a very similar system.

Regards, Alton <ajr@cfdrc.com> or (256)726-4919

Charles Crosby June 19, 2001 16:09

Re: Anyone use CFDRC?
 
Me too. I have used CFD-FASTRAN for the last year or so. I posted some of my experiences and impressions on this forum a few weeks ago.

Matt Gaston June 19, 2001 18:46

Re: Anyone use CFDRC?
 
I have used CFDRC software since 1997. I have used CFD-ACE, CFD-ACE(U) and CFD-FASTRAN.

windhair June 21, 2001 10:25

Re: Anyone use CFDRC?
 
Do you know how much grid point number can CFDRC worK?

Another questions is, I want to generate two block unstructureed grid, but the grid point on the same boundary of two block is not similar, what shall I do?

windhair June 21, 2001 10:30

Re: Anyone use CFDRC?
 
I can not find your post here.

can you post it to me through email?

windhair1@hotmail.com

windhair June 21, 2001 10:33

Re: Anyone use CFDRC?
 
sorry, my email address is : windhair1@yahoo.com

Charles Crosby June 21, 2001 17:01

Re: Anyone use CFDRC?
 
Windhair's e-mail addresses don't seem to work, so here is my summary of CFD-Fastran again. Sorry for the repetition!

Here you go. As for your other questions, in CFD-FASTRAN (and I suspect CFD-ACE as well) the face grids between two adjacent blocks need to match "exactly". There seems to be a difference between FASTRAN 3 and 4 in this regard, in version 3 it had to be a common face, in version 4 you can set a tolerance, which will presumably allow a small misalignment. I haven't actually used this feature, as we've become accustomed to building the grids with exactly matching faces. Re: CFD-FASTRAN

Posted By: Charles Crosby <ccrosby@mweb.co.za> Date: Sun, 20 May 2001, 2:56 p.m.

In Response To: CFD-FASTRAN (S. Russell)

I have been using CFD-Fastran for the last twelve months or so. It is the first commercial CFD-code that I have used (worked previously with self-written and other research codes), so I have no objective basis on which to compare the performance to Fluent or CFX, for example.

CFD-Fastran's Strengths:

1. Multi-block structured grid which allows degenerate faces and edges is quite an efficient way of meshing an external domain with boundary layer refinement.

2. Structured multi-block also lends itself to parallel processing, and the parallel license pricing is attractive relative to other CFD codes. (It is double the standard license, independent of the number of processors, unlike most other codes, where you have to buy a license for each CPU, albeit normally on a sliding scale) Given the very low price of high-end PC's at the moment, it is possible to follow a very economical "brute-force" approach!

3. CFD-Geom is now a very capable structured mesh generator, it has in fact improved very significantly over the 12 months that I have used it.

4. Capability to handle overset moving grids (for store-release simulation, for example) is its major competitive advantage, although I haven't actually used it yet!

5. Stability is reasonably good, although I have battled (without any obvious reason) with one or two solutions.

6. CFD-View is a very nice post-processor.

7. CFD-Geom is a pretty good "parametric" mesh generator. It is possible and practical, for example, to build a single mesh, and then distort the mesh for different control surface deflections. This makes it very quick to get meshes for slightly differing configurations.

8. There are currently three turbulence models available, k-epsilon, k-omega and Baldwin-Lomax.

9. Perhaps rather strangely for a density-based solver, it handles low Mach number flows very well.

CFD-Fastran weaknesses

1. On the basis of anecdotal comparison to other codes (like Fluent and CFX, for example), it seems rather slow. I have not accurately benchmarked this.

2. We sometimes battle with transsonic flows to get the residuals down. Integrated forces seem to "converge" very nicely, but the residuals get "stuck". Very difficult to make a confident statement about convergence in a situation like that.

3. CFD-View post-processor lacks the ability to integrate pressures to get forces on arbitrary walls.

4. It can handle unstructured meshes, but at the moment it is not possible to get an "advancing layer" prismatic grid, so practical boundary-layer type meshing is not really feasible with the unstructured mesh. I think the unstructured mesh is currently best suited to inviscid simulations, for this reason.

We will be renewing our license for CFD-Fastran for the next twelve months, which I guess says something about it. However, the best advice I can give is that you do really need to check and benchmark it against the opposition FOR YOUR APPLICATION.

John C. Chien June 21, 2001 17:47

Re: Anyone use CFDRC?
 
(1). I will go through your comments later on to get some feeling about the code. (2). I am sure that these are your own comments. So, Is your background training important? Without knowing the usr's background training, I guess, it is going to be hard to use your comments when applied to other users with different background. (3). What is the relationship between the user's backgraound training and the code? In other words, what are required from the user, in order to get the kind of your comments. (the age? the income level? the advanced degree? etc.) I mean the general background, if possible.

Charles Crosby June 22, 2001 15:14

Re: Anyone use CFDRC?
 
John,

Like most things on the www, these comments are for free, use you own judgement about the value that you want to attach to them! ** FWIW, it's just a repost of something I posted a few weeks ago, I tried to e-mail it directly to windhair, but it bounced.

** Meaning to say, anybody can write anything they want on the internet, there is no authority, no standard of truth, nothing. Just total freedom of speech (or screech), so it's up to the reader to use his discretion whether or not to believe anything. I could give you a full resume, but why should that be truthful ;-)

John C. Chien June 22, 2001 15:41

Re: Anyone use CFDRC?
 
(1). I agree with you totally. (2). Just hope that readers visting the forum are very smart in knowing what they are looking for. and (3). The comments represent the personal experience, not what were printed by the vendor.


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