# Force contours?

1. Sep 21, 2010

### leakeg

Hi physic peoples,

[for the tl;dr peeps: is there any point plotting a force distribution when I already have a pressure distribution, aren't they essentially the same thing?]

I've been doing wind tunnel experiments on structures for my final year engineering project, my supervisor (who I have a feeling knows less about the topic than me, which isn't much) has asked me to come up with contour plots for the forces on a model, and I'm wondering how to go about it, and if it is even possible.

What I have at the moment is a bunch of pressure values at various locations and from this contour plots of the Pressure Coefficient, Cp = (p - po)/(0.5ρV2) - it seems trivial to convert these values to forces for some corresponding area - simply multiply Cp by 0.5ρV2L2 - but this will be a force value for a specific area, and seems pointless to plot this when we already have the Cp values with are a dimensionless representation of pressure - a force per unit area.

Any thoughts are appreciated... from what I can tell "plotting the force distribution" seems like a fairly pointless exercise when I already have the pressure distribution, but I'm keen to hear some opinions.

Thanks in advance for any help!

2. Sep 21, 2010

Well the big question is how complicated your wind tunnel experiments are.

Do you differentiate between dynamic pressure and static pressure? If you have turbulence are there forces, that cannot be represented by an average pressure, like short bursts that would get averaged out? Can you say something about the stresses and torque inside your model?

Maybe answering some of this stuff can give you some ideas what you could present to your boss. Maybe not.

3. Sep 21, 2010