Quote:
Originally Posted by California98Civic
The tell-tales above the taillights and at the seam between your bed cap and the truck seem to indicate flow moving from the side to the top of the extension. Does that flow become turbulent as it intersects with flow from the roof?
|
I'll give a 'long' answer and see if I can cover all the bases:
*The air on the aero shell is moving at a greater velocity than on the sides of the truck due to the way the greenhouse has divided the airstream at the front.
*Since the aero shell has plan taper and the truck bed does not,the aero shell can undergo a continuous increase in tumblehome,whereas the bed box is stuck with it's upright sides.
*From Daniel Bournoulli's research findings,the static pressure around the aero shell will be lower than on the sides of bed.
*This pressure differential causes the higher pressure air near the bed rails to migrate upwards into the lower pressure air above the rails alongside the shell.
*It's still laminar flow,but it is tranverse flow.
*If the aero shell had a 'steeper' curvature than it does,the shearing forces would be strong enough to whip up into attached longitudinal vortices,causing high drag.
*Since the curvature is gradual enough the flow remains attached.
*From the photo you can see that by the time the air makes it to the boat tail,all the air is flowing longitudinally with no perturbations.
--------------------------------------------------------------------------
*Had the T-100 bed rails matched the plan taper of the aero shell it would be doubtful that any tranverse flow would occur.
*I was working on this issue in 2005 with the Dodge pickup,having created a mockup of a 'Template' truck bed when the T-100 showed up in my life.Perhaps before I die I'll be able to complete that project.This sort of bed would allow Cds which are half of the typical passenger car,Something pickup owners might appreciate at the gas pump.