|
[Sponsors] |
Hairpin vortices in turbulent channel flow using DNS |
![]() |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
![]() |
![]() |
#1 |
New Member
Nitin
Join Date: Mar 2012
Location: Bombay
Posts: 16
Rep Power: 14 ![]() |
Hello Foamers
I am performing DNS of turbulent channel flow to understand the relationship b/w hairpin vortices and heat transfer associated with it. In the literature, the formation of hairpin vortices is explained as follows: First of all, vortices formation in spanwise (z) direction due to gradient of streamwise velocity (du/dy) in wall normal (y) direction. Stretching and lifting of spanwise (z) vortices results in two counter-rotating vortices in streamwise (x) direction. These vortices elongate further in x direction and eventually connect at y+=15 and results in formation of hairpin. I am not able to understand the driving force behind stretching and lifting? Please share your experience and understanding. |
|
![]() |
![]() |
![]() |
![]() |
#2 | |
Senior Member
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,830
Rep Power: 73 ![]() ![]() ![]() |
Quote:
to understand this issue, start from the Helmholtz equation for the dynamics of the vorticity. The key is in the term (w. Grad v) that is non-vanishing in 3D. Such term (stretching term) is responsible for the alignemnt of the vortex tube along the stream-wise direction and the reduction of the tube section. |
||
![]() |
![]() |
![]() |
![]() |
#3 | |
Member
Jingchang.Shi
Join Date: Aug 2012
Location: Hang Zhou, China
Posts: 78
Rep Power: 14 ![]() |
Quote:
|
||
![]() |
![]() |
![]() |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Accuracy of LRR and SSG in turbulent channel flow | dradenkovic | OpenFOAM Running, Solving & CFD | 1 | August 23, 2016 13:03 |
turbulent channel flow | mn1363 | Main CFD Forum | 1 | January 14, 2013 13:05 |
How to get fully developed turbulent flow in a channel | TQIM | STAR-CCM+ | 2 | November 25, 2012 22:37 |
turbulent developed lenght in oppen channel flow | zandi | Main CFD Forum | 0 | January 9, 2010 14:52 |
Pressure drop across a turbulent channel flow | shiv | Main CFD Forum | 0 | September 21, 2005 00:52 |