|
[Sponsors] |
Farfield BC: vortex correction for lifting bodies |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
August 30, 2005, 12:17 |
Farfield BC: vortex correction for lifting bodies
|
#1 |
Guest
Posts: n/a
|
Hi,
i'm reading Blazek's CFD book and he said that for the farfield BC of lifting bodies, some corrections have to be made, namely in 2D, u(inf)(new) = u(inf) + (tau*sqrt(1-M(inf)^2)/2*pi*d)*sin(theta)/(1-M(inf)^2* (sin(theta-alpha))^2) v(inf)(new) = v(inf) + (tau*sqrt(1-M(inf)^2)/2*pi*d)*cos(theta)/(1-M(inf)^2* (sin(theta-alpha))^2) tau is circulation, (d,theta) are polar coordinates of farfield, M(inf) is freestream mach no. I would like to check if I can apply this to incompressible NS eqns. I'm using the fractional-step btw. Moreover, is this helpful in incompressible flow? It's stated that the farfield radius can be reduced by an order of magnitude when used. please comment. thanks! |
|
August 30, 2005, 23:52 |
Re: Farfield BC: vortex correction for lifting bod
|
#2 |
Guest
Posts: n/a
|
This correction can be applied for lifting flows. Hence it is most appropriate for subsonic flows but might also help for transonic flows. For imcompressible flow, I think it is enough to put M(inf)=0 in those formulae. Also see the following reference
MD Salas JL Thomas, Far-Field Boundary Conditions for Transonic Lifting Solutions to the Euler Equations, AIAA Journal, vol. 24, no. 7, 1986 |
|
September 6, 2005, 03:10 |
Re: Farfield BC: vortex correction for lifting bod
|
#3 |
Guest
Posts: n/a
|
ok thanks. but has anyone used this correction before? Is it effective ie reducing the farfield location by quite a bit?
Thanks |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Vortex in an intake pipe, critical submergence | Julien Pralong | FLOW-3D | 1 | October 23, 2010 16:24 |
creating vortex core line | aay023 | Main CFD Forum | 0 | September 15, 2010 22:49 |
Pressure farfield vs Velocity Inlet BC | DarrenC | FLUENT | 1 | September 16, 2009 03:23 |
turbulent scales of forced vortex and free vortex | lcw | Main CFD Forum | 3 | September 1, 2005 14:40 |
Kármán vortex street in cavitating flow behind bodies in the cavitation tunnel | L. Könözsy | Main CFD Forum | 0 | April 17, 2000 14:16 |