|
[Sponsors] |
November 2, 2006, 13:37 |
Boundary Layer Equations
|
#1 |
Guest
Posts: n/a
|
Hello! Does anyone has idea on solving unsteady boundary layer equations. I have two methods on hand: Fully implicit method and Box method. Which one is better to solve a 2-D compressible unsteady boundary layer equation? Thanks for your advice.
|
|
November 3, 2006, 06:28 |
Re: Boundary Layer Equations
|
#2 |
Guest
Posts: n/a
|
I'd use the Keller Box method - it's implicit + 2nd order accurate in space and time.
|
|
November 3, 2006, 15:02 |
Re: Boundary Layer Equations
|
#3 |
Guest
Posts: n/a
|
Thank you, Tom.
I have some more questions. 1.Will box method become tedious when governing equations reach four or five ( there might has 7 by 7 matrix inversion and linearization become tedious )? 2. Is variable transformation necessary for compressible flow? 3. How you advice to do the matrix inversion(implicitly? )? My email is: JakyL6@hotmail.com. I would appreciate any advice. |
|
November 6, 2006, 03:36 |
Re: Boundary Layer Equations
|
#4 |
Guest
Posts: n/a
|
1. It's only redious if you try to do it by hand.
2. It depends on your problem. Most boundary layer calculations are initiated from a similarity solution which can involve a change of transverse coordinate. If a vertical cordinate transformation is required at the initial station then it's a good idea to solve the equations everywhere in this new coordinate. 3. The way I would perform the inversion is through a block LU factorization. Assuming you've rearanged the equations (as you're Q1 suggests you have) so that the only nonzero entries lie on in a band around the diagonal then you can rewrite your matrix as a triagonal system whose entries are 3x3 matrices. The LU factorization will also be of this form and so it is relatively easy to invert; i.e. follow the methodology for a tridiagonal system with the scalars replaced by 3x3 matrices. Alternatively you could use a general matrix solver such as BiCG - Although it will be a lot slower. |
|
November 6, 2006, 11:34 |
Re: Boundary Layer Equations
|
#5 |
Guest
Posts: n/a
|
Tom, Thanks a lot.
|
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Turbulent Boundary Layer on a Flat Plate | Hoshang Garda | FLUENT | 1 | November 27, 2013 10:24 |
[snappyHexMesh] Boundary layer in a pipe | Clementhuon | OpenFOAM Meshing & Mesh Conversion | 6 | March 12, 2012 12:41 |
Combining BCs: wall - outlet. Boundary layer disappears | MartinaF | OpenFOAM Running, Solving & CFD | 1 | July 20, 2009 18:14 |
New topic on same subject - Flow around race car | Tudor Miron | CFX | 15 | April 2, 2004 06:18 |
Wall turbulence, viscosity, boundary layer | Patrick Godon | Main CFD Forum | 1 | November 5, 2003 15:39 |