×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

2D Airfoil Analysis using Flotran

2D Airfoil Analysis using Flotran

2D Airfoil Analysis using Flotran

(OP)
Can anyone tell me how to get realistic drag values using Flotran to analysze an airfoil.  When I do the surface integral on the airfoil, the lift I am getting seems to be very accurate but the drag has negative values.....any sloutions???

RE: 2D Airfoil Analysis using Flotran

Have you considered using DesignFOIL or SNACK for your 2D analysis?  It's right on the money and works amazingly fast.  Nice interface too.  They can be gotten from www.dreesecode.com

RE: 2D Airfoil Analysis using Flotran

Al (Einstein) tought us that everything depends on reference coordinate system.  So if my powerplants produce positive (thrust) forces the drag has to be negative.  Therefore you shouldn't bother with the sign if absolute value (amount) of the drag seemed all right.

RE: 2D Airfoil Analysis using Flotran

Hi
Check your UCS once again.
The X axis has to be parallel to the cord and Y perpendicular to it, facing upwards. It is a good idea to place the airfoil so that the leading edge has (0,0,0) coordinates. This way the X axis is right on the cord.
Also, are you using the intsrf,pres command for the integration of pressure along the airfoils surface (for the lift & drag calculations), or the intsrf,tauw command of the integration of shear stress (also used for the drag calculations in viscous flow)?
I hope this will help
gkoz

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources