How to Calculate Wind Load on a Rectangular Antenna 3

[SolSurfer1]

I need to calculate the wind-loading force (lbf or N) that will be applied to my rectangular antenna enclosure (face area of 2.6 sq ft /0.24 sq m) in a wind speed of 60mph (97km/h. The estimated drag coefficient (based on a flat face with rounded edges) is 1.9.
Can someone provide me with the correct formula to use, or point me I the direction to solving this?
Thank you,
Solsurfer1

 

[Wrenchbender]

Check a fluids book or wikepedia. I think the eqn is F = 0.5 * Cd * rho * v^2 * A (maybe throw in a 1/g for correct units). Rho is air denisty, 0.075 lbs/ft^3 should be close enough. Other symbols should be obvious.

 

[dhengr]

SolSurfer:
Fluid mechanics and wind tunnels is one approach. Structural engineers look to ANSI/ASCE 7- latest ed., for wind loads on structures, and it’s a real mind bender, but it is the building code for these kinds of things.

 

[DFLewis]

I agree with dhengr...

ASCE 7-latest edition should walk you through the analytical process to determine an applied force for your structure. I find non-building structures to be easier to analyze and less "mind bending" as dhengr put it. It does take a little guidance to get through all of the variables though the first few times.

DFLewis

http://www.phoenix-engineer.com

 

[Ron]

SolSurfer....Assuming you are in the US, the minimum wind load that should be applied is 90mph. That's the starting point. As dheng noted, ASCE 7 is the defining document, as laborious as it might be to check your specific requirement.

 

[rb1957]

i've been discussing the same post over in the aero. forum ... make me think he was putting an antenna on a plane.

anyways, i was wondering if the code defined the wind speed, then the load is 1/2rhoV^2*A, or the pressure, then the load is p*A ...