CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Transient parameters for vehicle aerodynamics

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 27, 2019, 11:33
Default Transient parameters for vehicle aerodynamics
  #1
New Member
 
Sadat
Join Date: Sep 2019
Posts: 1
Rep Power: 0
kansei_dorifto is on a distinguished road
Hello everyone!


Im very new in CFD. Currently I am doing external aerodynamics analysis of 3D car model for a university project work. I verified Ahmed Body with around 5% error for the 25 degrees with realizable K-e model (huge thanks to https://www.youtube.com/user/eoescipy - very detailed step by step guide).
My intention, however is to capture the rotating effects of wheel rims, which I recently found out, requires me to do a sliding mesh approach -hence a transient simulation. Now I have next to zero idea about how to set up transient parameters like time step size, no. of time steps etc. And unfortunately I dont have enough time to learn about transient simulation from scratch - I have to show some progress to my project supervisor.

So basically what Im asking is that - what are considered good practices for setting up transient parameters for external aerodynamics in particular such as time step sizes, no. of timesteps, max iterations etc. I need a range of values for them to work on immediately. I understand that I am sounding lazy, but I am so time constrained right now that I simply dont have the time to experiment with transient parameters - which is why Im asking for help. Any kind of tips would be greatly appreciated.



Im describing my method as much as possible-

Turbulence model- realizable k-e NWF

Inflation - First Aspect Ratio 5, 5 layers (y+ around 100-120)
Solution methods, Solution Controls - Please see attached screenshots. I modified the relaxation factors according to the video.


Mesh is very similar to the meshing in the given youtube channel, which meshes the Ahmed body . I will just switch out Ahmed body with my car.

Once again, Im really in trouble right now- and I will greatly appreciate any kind of help. Thank you!
Attached Images
File Type: png Capture.PNG (8.5 KB, 3 views)
File Type: png s.PNG (14.3 KB, 3 views)
kansei_dorifto is offline   Reply With Quote

Reply

Tags
fluent, transient 3d, vehicle aerodynamics

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
Transient Blade Row - Time Transformation - Transient Details awesim CFX 16 August 6, 2016 10:40
Defining transient export parameters kez FLUENT 0 March 3, 2016 11:22
Transient or Transient Blade Row? liucheng8602 CFX 2 June 19, 2014 08:03
transient simulation of a rotating rectangle icesniffer CFX 1 August 8, 2009 08:25
Transient vs Steady State Adam CFX 1 April 12, 2007 12:34


All times are GMT -4. The time now is 22:23.