|
[Sponsors] |
June 14, 2001, 19:54 |
Translational reference frame
|
#1 |
Guest
Posts: n/a
|
Hi! there,
Could you introduce the "Translational reference frame"? and how the N-S equations are changed? or tell me some reference/paper that I can read? Thank you very much. Ray |
|
June 15, 2001, 00:18 |
Re: Translational reference frame
|
#2 |
Guest
Posts: n/a
|
Aren't the NS equations invariant under a galilean transformation? You could check for yourself by just apply the transformation to velocity that "V.b = V.a + V.b wrt.a" Seems to me that no additional acceleration terms would appear in the momentum equations, as the translating velocity (V.b wrt a) just disappears when you take the derivatives.
Note that this is definitely not the case for a rotating domain. |
|
June 15, 2001, 11:46 |
Re: Translational reference frame
|
#3 |
Guest
Posts: n/a
|
NS equations with no body forces are also Galilean invariant under rotation since rigid body type motions do not lead to additional stresses.
|
|
June 16, 2001, 04:49 |
Re: Translational reference frame
|
#4 |
Guest
Posts: n/a
|
yeah but who cares about the case when there's no body force?
|
|
June 18, 2001, 10:40 |
Re: Translational reference frame
|
#5 |
Guest
Posts: n/a
|
In most LES papers, people claim that their (subgrid) model is Galilean invariant by just showing its invaraince under translational motion. Some such models do not have invariance under rigid body rotation. Subgrid terms should be invariant under any type of rigid body motion. Even when you have density change and bouyancy effects, it is worthwhile checking if the model is Galilean invariant in the limit of microgravity.
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Second Derivative Zero - Boundary Condition | fu-ki-pa | OpenFOAM | 11 | March 27, 2021 04:28 |
Error with Wmake | skabilan | OpenFOAM Installation | 3 | July 28, 2009 00:35 |
OpenFOAM on MinGW crosscompiler hosted on Linux | allenzhao | OpenFOAM Installation | 127 | January 30, 2009 19:08 |
G95 + CGNS | Bruno | Main CFD Forum | 1 | January 30, 2007 00:34 |
Building OpenFoAm on SGI Altix 64bits | anne | OpenFOAM Installation | 8 | June 15, 2006 09:27 |