|
[Sponsors] |
May 13, 2014, 12:45 |
Prediction of the critical Reynolds number
|
#1 |
Member
Sami
Join Date: Nov 2012
Location: Cap Town, South Africa
Posts: 87
Rep Power: 14 |
Hi every one,
I'm using OpenFoam for simulating fluid flow in periodic media. Do you have an idea on how can I predict the laminar/turbulent transitional Reynolds ? Thank you in advance Mehrez |
|
May 15, 2014, 02:36 |
|
#2 |
Senior Member
Karl-Johan Nogenmyr
Join Date: Mar 2009
Location: Linköping
Posts: 279
Rep Power: 21 |
Well, in theory it should be possible using a DNS solver and sweep the Re-number, while assuring there is some small disturbances present. If you are below the critical number, the disturbance should decay, while if you are above, it should grow (into turbulence).
In practise it is tricky because you need to assure that your numerical viscosity is small enough (to be accurate in Re), and things like wall roughness may play significant role. For an academic case (smooth wall), this is possible with OpenFOAM, (dnsFoam solver), but you would need massive computational resources (i.e. hyper-fine mesh) K |
|
May 15, 2014, 12:21 |
|
#3 |
Member
Sami
Join Date: Nov 2012
Location: Cap Town, South Africa
Posts: 87
Rep Power: 14 |
Hi dear Kalle,
Thank you for your answer. Concerning my geometry, I have smooth walls. I have proceeded like you said by DNS (using IcoFoam solver with dimensionless NS equations). I have got results but I want to verify if it is OK. I thought about the linear stability theory but OpenFoam doesn't have a such solver, so to validate my DNS results I need to adopt another method... Best regards, Mehrez |
|
Tags |
laminar/turbulent, reynolds, transition, unsteady |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
decomposePar pointfield | flying | OpenFOAM Running, Solving & CFD | 28 | December 30, 2013 16:05 |
AMI interDyMFoam for mixer | danny123 | OpenFOAM Running, Solving & CFD | 4 | June 19, 2013 05:49 |
Stable boundaries | marcoymarc | CFX | 33 | March 13, 2013 07:39 |
Two way particle coupling in OF 2.0 and the particle reynolds number | preichl | OpenFOAM | 7 | February 9, 2012 16:38 |
Critical Reynolds Number | Dipankar Chatterjee | Main CFD Forum | 0 | September 4, 2002 11:01 |