Quote:
Originally Posted by kach22i
I have to give this some more thought.
I somehow believed there was a great deal of lift with the Aero-template.
The airfoil myth
The airfoil myth
I'm not sure how mainstream the blog above is, perhaps some sort of radical or heretic? |
All wing sections have an angle of attack of zero lift.It is referred to as the 'bottom of the 'bucket.'' A look at Abbott and von Doenhoff's book on wing sections will illustrate it.
Half-bodies of revolution are similar to wing sections when viewed from the side,however,in no way resemble a wing in plan view (looking from the top down).There's no 'span.'
Since a streamlined body of revolution is streamlined,the rearward stagnation pressure is nearly identical to the forward stagnation pressure,with only a loss in energy,equal to what is lost with skin friction,which is the absolute minimum with the template,on account of it's specific fineness ratio.
Lift IS produced over the maximum cross-section on top,but is cancelled at the nose and tail.As long as angle of attack is not introduced.
At 135-mph,Spirit's nose produces negative 30-pounds (downforce),and the tail produces positive 22-pounds of (lift).For a 4,200-pound vehicle this lift is 'meaningless At legal speeds lift is unmeasureable.
We can't use the lift data for the baby template car due to how it was fashioned to the load cells but according to Kamm and Fachsenfeld, these half-bodies are incapable of producing lift.
Now if you get the car sideways at high speed,that's another matter all together!
I used to have graphics to share from Photobucket,but I've lost the use of all of them.