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

lift & drag coefficient on 2d airfoil

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 31, 2015, 13:53
Default lift & drag coefficient on 2d airfoil
  #1
New Member
 
Ronald Thompson
Join Date: Mar 2015
Location: Portland, Oregon, USA
Posts: 25
Rep Power: 11
dynamic is on a distinguished road
Hi,
im trying to determine lift and drag coefficients from my fluent model and validate them against publications, at the moment I can't get my Cl and Cd to match with the published material, Im using a NACA0018 airfoil and at the moment i'm only dealing with small AOA <10 degrees, I'm using an Inviscid model in fluent, with a C mesh for my fluid domain, (see mesh attached) Ive used an automatic triangles method in general and then applied sizing around the foil with inflation in this area also.

Ive carried out a mesh convergence test and i do get my results to converge but not to the correct answer, i seem to be an order of magnitude out in most cases. my boundary conditions seem to be correct,

I dont know where exactly the issue is, any help would be appreciated.
Attached Images
File Type: jpg pastedImage.jpg (98.9 KB, 29 views)
dynamic is offline   Reply With Quote

Old   March 31, 2015, 15:38
Default
  #2
New Member
 
Join Date: Nov 2014
Posts: 9
Rep Power: 11
Exkalabur22 is on a distinguished road
What is your reason for using Inviscid flow? Are you comparing your results to other CFD calculations or real world results? You should consider your Reynolds number too. Check your reference values to make sure they are correct for calculating the CL and CD.
Exkalabur22 is offline   Reply With Quote

Old   March 31, 2015, 18:54
Default
  #3
New Member
 
Ronald Thompson
Join Date: Mar 2015
Location: Portland, Oregon, USA
Posts: 25
Rep Power: 11
dynamic is on a distinguished road
hi, the results i am using for comparison are based off published experimental results. I have considered the Reynolds number I used it to ensure i was making the correct comparisons, the reference values also seem to be correct. the reason I chose an Inviscid model was because I seen it in a tutorial previously and i was only using it on small angle of attacks, as I was presuming a turbulence model wasn't necessary with a Reynolds number based off 160k, I also had ran a version using a Laminar flow model but still could not get any closer to the required results.
dynamic is offline   Reply With Quote

Reply

Tags
airfoil 2d, coefficient drag., coefficient of lift, fluent 14.5


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
Drag and lift coefficient for supersonic flow Nick R Main CFD Forum 0 September 28, 2014 03:25
Wrong Drag and Lift Coefficient when changing AoA inspiron FLUENT 1 November 27, 2013 14:00
lift, drag and moment of airfoil dennis0131 Main CFD Forum 10 April 27, 2010 13:12
Symmetric NACA Airfoil Lift and Drag Data jrider22 Main CFD Forum 3 April 15, 2010 05:59
drag and lift coefficient Noé Siemens 5 July 13, 2004 11:21


All times are GMT -4. The time now is 23:41.