Quote:
Originally Posted by orbywan
More good information, thanks aerohead. I kept looking at the side deflectors on the semi's on the road and wondering exactly what the goal was there. Duh.
The undercarriage of my RV is obviously different that a semi's trailer, but do you think I should try the same approach, long diverter pushing the air to the outside of the each wheel set? That would be assuming no belly pan.
With a belly pan, would the general design be the same do you think?
|
There are two schools with respect to sides:
(1) make the flanks of the vehicle flush with the outside of the wheels and put a smooth wheel cover on.Allow some ventilation of the cover to help brake cooling on mountain downgrades.
(2) inset the wheels a bit,allowing a full skirt to be added.Provide shark gill exits to blend brake cooling air along the sides of the rig.
------------------------------------------------------------------------
The belly would be done as any.Renault demonstrated a 17% drag reduction with a full pan on VIRAGE.
Fachsenfeld got an OMNIBUS inter-city bus into the low Cd 2s with a pan.Under Cd 0.2 with inflated tail.
------------------------------------------------------------------------- On low drag vehicles the wheel drag can be half the drag.It's worth going after.
See what you've got and maybe take the easiest path.
--------------------------------------------------------------------------
PS,I looked up the Omnibus in Hucho's book.This is actually the first K-Tail,the K coming from Koenig in Fachsenfelds name.He beat Kamm to the patent office.Although Carl Breer had done a 'chopped tail' in 1934 with Airflow.
The bus,with inflated boat-tail had Cd 0.158.