|
[Sponsors] |
August 24, 2006, 07:07 |
the difference profile in the empty domain
|
#1 |
Guest
Posts: n/a
|
Hello,
My study is on neutral atmospheric boundary layer wind tunnel. the inlet boundary was well known as U(z)=u*ln(z/z0)/k, outlet as outflow,sides and top as symmetry. z0, k and eps were got from the previous wind tunnel test. Realisable k-eps,two layer wall funciton,smooth wall, structured mesh and second order were used in the empty domain. After convergence, there was a large difference between inlet profile and outlet profile. Then grid was refined, but the problem still existed.If I use the cyclic conditoin between inlet and outlet, the constant profile can be got, but it was not what I wanted. How can I achieve the consant profile in the empty domain? your comments will be appreciated Justin |
|
August 25, 2006, 07:32 |
Re: the difference profile in the empty domain
|
#2 |
Guest
Posts: n/a
|
Now I found the reason, which was related to the epsilon. the well known equation eps=u*/(kz)made this problem, but it is difficult to solve. If we use the equation eps=Cu^(3/4)*k^(3/2)/l, eps looks like a constant, but accturally it is a variable with the vertical. also l and Cu is a changeable constant with the condition.
How do you describe the eps? please give any comments. Thanks Justin |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
problem in setting the domain to empty | Prince | OpenFOAM | 5 | May 6, 2011 14:39 |
CFX domain comparison | Kiat110616 | CFX | 4 | April 3, 2011 23:43 |
How to model the NR eqns in a domain with empty space | Vasilis | Main CFD Forum | 1 | April 14, 2009 05:35 |
[Domain]Three different Domain | Young | CFX | 3 | April 27, 2008 15:11 |
How to form a constant profile in the empty domain | justin | FLUENT | 1 | August 23, 2006 09:43 |