CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Main CFD Forum (https://www.cfd-online.com/Forums/main/)
-   -   1 billions cells: useless? (https://www.cfd-online.com/Forums/main/16020-1-billions-cells-useless.html)

Steve November 20, 2008 10:10

Re: 1 billions cells: useless?
 
This from CD-Adapco's most recent e-newsletter

"Find out how CD-adapco broke the Billion Cell Barrier over a year ago ..."

Words like "knee", "jerk" and "reaction" spring to mind.

Jeff Vader November 20, 2008 11:22

Re: 1 billions cells: useless?
 
Yes, next thing you know adapco will be telling us that they invented polyhedral meshes first too...

JV

ahem November 20, 2008 12:08

Re: 1 billions cells: useless?
 
The name 'legacy code' circa 2000 springs to mind :)

sarah-plain November 20, 2008 16:42

Re: 1 billions cells: useless?
 
sort of. We are supposed to calculate drag and lift. So mainly turbulence.

sarah-plain November 20, 2008 16:44

Re: 1 billions cells: useless?
 
Has it ever occured to you that may be my company does not want me to say anything on this regard.


momentum_waves November 21, 2008 04:01

Re: 1 billions cells: useless?
 
sarah-plain wrote:

Has it ever occured to you that may be my company does not want me to say anything on this regard.

For someone who shouldn't be talkative, you've certainly done your company proud. :)

sarah-plain November 21, 2008 05:31

Re: 1 billions cells: useless?
 
For someone who shouldn't be talkative, you've certainly done your company proud. :)

I have not written anything that is not in the public domain. Much much more than what i wrote is already published in papers. (further you do not know what my company is). So yaa if someone wish to guess, thats fine by me.

I just do not want to write it here.


underGroundMan November 21, 2008 05:57

Re: 1 billions cells: useless?
 
I just received a e-news letter from cd-adapco in which they mentioned that they broke 1 billion cell barrier year a go. So, Sarah, you have nothing to be proud of.

I totally agree with Andrew, it is useless to get mean results with one billion cells. I am sure RANS would have given you same results even with half of what you have used. Using RANS modelling with that many cells is pointless.

Steve November 21, 2008 08:11

Re: 1 billions cells: useless?
 
underGroundMan,

See my Thu 20 post in this thread.

Don't you think it's quite a coincidence that CD decide to share this information now and then boast that it was over a year ago?

Jeff Vader November 21, 2008 09:14

Re: 1 billions cells: useless?
 
Check the date and then stop making duck noises: http://www.deskeng.com/articles/aaafsg.htm

Steve November 21, 2008 10:00

Re: 1 billions cells: useless?
 
<more duck noises>

So why is work that's that old in a "news" letter?

Jeff Vader November 21, 2008 10:16

Re: 1 billions cells: useless?
 
I guess that the adapco marketing people wanted to show that ANSYS marketing people were telling fibs...

The words "don't" "know" "what" "you're" "talking" "about" come to mind.


underGroundMan November 21, 2008 10:57

Re: 1 billions cells: useless?
 
May be cd-adapco did not consider it a milestone at that time. But now when Sarah Palin's company started bragging about their work, cd-adapco reminded them how far behind they are!

Donald November 21, 2008 14:39

Re: 1 billions cells: useless?
 
no the polyhedral meshing was copied from medical imaging softwares that existed from a very long time ago to discretize body part and to visualize them. The principle was is many open sources. It was just copied to CFD codes.

There is a also no point solving 1 billions if you cannot afford the licenses for the solver on all the processors.


sarah-plain November 21, 2008 18:11

Re: 1 billions cells: useless?
 
But now when Sarah Palin's company started bragging about their work, cd-adapco reminded them how far behind they are!

i think you need to learn to read.

1. How did you decide that our company bragging. 2. I certainly do not work with ANSYS, in fact i never thought it is big deal. 3. I am sure with todays resources it is not big deal.

Personally it would be big deal for me if i could get the same results in meshes less than 5 or 10 million cells. Speed and time is where my interest lies.

Mickey November 22, 2008 11:22

Re: 1 billions cells: useless?
 
While CD-adapco did not invent polyhedral meshes, it made them work for CFD which is not the same as copying. Building a mesh that a CFD solver can accept is a lot different than what is required for simple visualization. If it was simply copying, Ansys would also have a workable poly-mesh generator instead of just talking about having one.

In fact you can buy a license from CD-adapco for unlimited numbers of processors attached to a single analysis so if you have the hardware, you can afford the software.


Louis November 22, 2008 18:05

Re: 1 billions cells: useless?
 
you need to be able to reference:

Area(i), Vertex(i), Volume(i), Connectivity(i) etc... and organize the arrays in the data structure to be able to find them in the solver...

It requires mainly cleanliness in the coding, but as you said nothing new from what was done in the medical field.


Ahmed November 22, 2008 19:32

Re: 1 billions cells: useless?
 
http://www.cd-adapco.com/press_room/...sport_CFD.html

UnderGroundMan November 23, 2008 09:57

Re: 1 billions cells: useless?
 
Sarah may be cd-adapco can help you in this regard. Considering they broke 1 billion cell barrier year ago, they are way ahead of you guys. I dont know why did you waste your resources on 1 billion cells when you were going to run RANS simulation? Even school kids can run such simulation.

sarah-plain November 23, 2008 16:34

Re: 1 billions cells: useless?
 
Sarah may be cd-adapco can help you in this regard. Considering they broke 1 billion cell barrier year ago, they are way ahead of you guys.

Are you three year old or what. Do you think there is some kind of competition going on to reach one billion cells.

English is not your first language, i have written multiple times that i thought it was not a big thing. So apparantly i thought many guys have already done it. (including F1 guys).

I dont know why did you waste your resources on 1 billion cells when you were going to run RANS simulation?

you know nothing about CFD.

Even school kids can run such simulation.

Yepp this statement very much indicates where you belong and what level you think at.


All times are GMT -4. The time now is 17:15.