CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

Problem with convergence using 2nd order scheme for multiple elements car wing

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   December 31, 2016, 09:42
Default Problem with convergence using 2nd order scheme for multiple elements car wing
New Member
Join Date: Dec 2015
Posts: 1
Rep Power: 0
Trytytka is on a distinguished road

firstly, Happy New Year for everyone I have a problem with convergence in calculations of multiple element front wing for car. I use k-omega SST turbulence model, velocity value 20m/s. First, I used first order for all equations exclude pressure (2nd order). After I got convergence (point 1 on picture) I changeg for 2nd order for everything. Unfortunately I canít get converge solution using 2nd order scheme. Residuals stuck and only oscillates about some average value, but the Cl and Cd takes aprox. state values. I tried decrease under-relaxation factors (point 2 on the picture one), but it doesnít help. I want to be implement the wall law so I must have y plus between values <30,300>, right? I calculated estimated y plus value and used an inflation option in meshing (the mesh is on the picture, Iím using ANSYS mesher). When I plot x-y plot of y plus value some values falls behind 30 (for plot I choose all surfaces of wing, is it right or maybe it should be done different?). I tried also double precision, but nothing changed, residuals got stuck. My question is, what can I do for getting convergence result, is this maybe problem of mesh (max. orthogonality about 0,78) or maybe even the residuals got stuck the solution is proper? Also how can I control the mesh for getting everywhere y plus value above 30? And the last question is that in the k-omega model wall law is implemented automatically? Please give me some advices.

Attached Images
File Type: png Convergence1.png (51.7 KB, 11 views)
File Type: png mesh.png (103.0 KB, 9 views)
Trytytka is offline   Reply With Quote


airfoil, convergence, wing

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
2nd order upwind and QUICK scheme Wiroon Main CFD Forum 19 September 17, 2019 03:47
Layers and 2nd order elements error Kyriakos ANSA 1 November 29, 2016 09:49
Convergence problem of a flow around a 3D Wing Gilles CFX 4 June 17, 2008 10:04
1st - 2nd order - convergence antonio FLUENT 4 December 16, 2004 08:37
2nd order boundary condition for QUICK scheme Jafarnia Main CFD Forum 0 February 25, 2004 09:03

All times are GMT -4. The time now is 19:05.