## Lift and drag over airfoil

Moderators: davetaflin, salter, steve, jprenaud, straton, Chris Idso

filippo.aero
Newbie
Posts: 3
Joined: Fri Jun 01, 2012 11:47 am
Location: Italy

### Lift and drag over airfoil

Hello to everyone, I just started to use Tecplot for analyzing a flow created by a CFD code, but I can't get the lift and drag of an airfoil.

When I use the analyze->integrate tool, and set the integration to forces and moments, I get an error message saying:
"Cannot integrate Forces and Moments over 2-D finite-element zones in 2D Cartesian plots (zone 1 is finite-element)"

Any idea or suggestion?

aritzmann
Jedi Master
Posts: 127
Joined: Mon Nov 20, 2006 2:26 pm
Location: Princeton, NJ
Contact:

### Re: Lift and drag over airfoil

Hi,

If I remember the CFD analyzer correctly (and it has been a few years since I really used it), the forces and moments are calculated on a surface by considering the fluid flow in the adjacent regions of space. This means that in a 2D plot, the forces and moments are integrated over a line (closed loop representing the airfoil cross section). If you have a full surface, then you need to switch the plot to 3D Cartesian and activate the volume zones around the the airfoil surface.

I hope this helps a little bit,

Andrew
Andrew Ritzmann

filippo.aero
Newbie
Posts: 3
Joined: Fri Jun 01, 2012 11:47 am
Location: Italy

### Re: Lift and drag over airfoil

Unfortunately my problem is a 2-d flow, so I can't switch to a 3-d cartesian. How do I integrate over a line?

aritzmann
Jedi Master
Posts: 127
Joined: Mon Nov 20, 2006 2:26 pm
Location: Princeton, NJ
Contact:

### Re: Lift and drag over airfoil

Hi,

You need to define an additional zone which is the boundary of the airfoil. Then you integrate over this zone to get forces and moments.

Andrew
Andrew Ritzmann

filippo.aero
Newbie
Posts: 3
Joined: Fri Jun 01, 2012 11:47 am
Location: Italy

### Re: Lift and drag over airfoil

First of all thanks for your help.
Then how can I create this zone? Which parameters should I use?

### Who is online

Users browsing this forum: No registered users and 1 guest