View Single Post
  #6  
Old July 17th 08, 07:39 AM posted to rec.aviation.homebuilt
cavelamb himself[_4_]
external usenet poster
 
Posts: 474
Default Aerodynamic...but not aircraft

Andy Asberry wrote:

3/4 ton extended cab pickup towing a 24 foot travel trailer. Fuel
mileage is effected much more by wind than weight.

I want to build a camper shell that will be cab high at the front and
direct the airflow smoothly over the trailer.

There is about 4 feet between the front of the trailer and the rear of
the proposed camper. For some reason, I believe the camper should be
higher than the trailer. But how much higher? Should the angle be
constant? Convex? Concave? A different exit angle?

About a foot from the top of the trailer, the front slopes back at a
45 degree angle. All opinions are welcome but educated calculations
will be given more weight.

--Andy Asberry--
------Texas-----



Best solution at lowest cost?

Slow down.

There is no induced drag here - only parasitic drag.

D = 1/2 Rho Cd S V^2

Also

Thrust Horsepower required = (D*V)/375
Which brings V up to a cube.

FWIW...

--

Richard

(remove the X to email)

America has become thouroughly convinced that the lunatics
are running the assylum and good idea or no, it will take
more that George W Bush at a press conference to reclaim
the public trust this administration has wantonly destroyed.

John R. Corroll