CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Question from a beginner

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

LinkBack Thread Tools Display Modes
Old   August 11, 2004, 07:55
Default Question from a beginner
Arun K
Posts: n/a
Sponsored Links
Hello all, being a newcomer to cfd, I have many unanswered questions on which you could enlighten me: 1. i do not have access to any commercial cfd package like fluent etc. So, would it be possible to progress QUICKLY as far as the lid driven cavity problem using C or MATLAB or FORTRAN? What is the approximate time required to code the above problem with each of these three languages and would commercial CFD codes help in reducing the time required to code? 2. What are the computational resources required to install FLUENT? Thank you. ~AK
  Reply With Quote
Sponsored Links

Old   August 11, 2004, 12:48
Default Re: Question from a beginner
Junseok Kim
Posts: n/a
check the below website and I am pretty sure they have an example test problem for the lid driven cavity. What's more, it has detailed text book related to its code.

  Reply With Quote

Old   August 11, 2004, 20:16
Default Re: Question from a beginner
Posts: n/a
Hi Arun,

First, if you are a student, you can ask your supervisor to buy an academic licence. It is fearly cheap compared to the price they for industrial licenses. All major CFD codes are now avalaible for PCs.

Second of all, if you go with your home made solver, you do not "code a problem". What you code is the numerical method that will solve the NS equations. The time depends on the method you chose and the number of applications you want to solve. Let say it can go from 1week to a life time...(depending on the number of bugs...).

I a gave a quick look to NAST 3D, it seems verywell documented and is very easy to build. Moreover, it comes with the cavity flow.

Good luck
  Reply With Quote

Old   August 13, 2004, 05:28
Default grid size
Posts: n/a
Hi, Can any one tel me (in more details) how can I see the the influence of the grid size on the computed solution. I'm traying to use a vof code. thanks.
  Reply With Quote

Old   August 13, 2004, 07:17
Default Re: grid size
Posts: n/a
1) Solve the problem with coarse grid and then solve it again with systematic grid refinement on 2 (or 3) other grids. Let say the mean size with the coarse grid is h0, then the size for the other grids can be chosen like this:

1D) h1=0.5*h0, h2=0.5*h1 and so forth. 2D) h1=0.7*h0, h2=0.7*h1 and so forth. 3D) h1=0.8*h0, h2=0.8*h1 and so forth. This choice will most likely double the number of grid points from one grid to the other one.

When the exact solution of the problem is known (which I doubt if you are using VOF), the rate of convergence of the scheme can be measured for the problem beign solved.

Then you can compare the solutions and compute reference quantities that apply to your problem. (Such as the drag).

2) You can also try to refine the mesh in region of interest (like the boundary layers). But it is not as straithforward as the other method.
  Reply With Quote


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
question about uds tanven FLUENT 2 July 5, 2015 11:22
Beginner Question me.ouda FLOW-3D 2 May 3, 2010 17:47
Question about Table applicaiton. universez OpenFOAM Running, Solving & CFD 0 January 12, 2010 21:31
Beginner question :(. Turning on and off zones? Cjlaumans FLUENT 6 September 2, 2009 15:44
Poisson Solver question Suresh Main CFD Forum 3 August 12, 2005 04:37

Sponsored Links

All times are GMT -4. The time now is 08:19.