Quote:
Originally Posted by JulianEdgar
Sure
Only if you think that's how box cavities work. I don't think that - because they reduce drag even when the extensions are not angled inwards and so when there's no reduction in cross-sectional area.
It's the old thing - to a hammer everything looks like a nail. Or, once you have a theory in your mind, you want to apply it to everything.
|
Very true! As with Hucho's example behind the VW Transporter.( another example from Hucho, is the elongated rectangular 'lozenge', resembling an Airstream trailer body, which hit minimum drag at a particular length.
What would be instructive, would be a side-by-side comparison, one with, and one without the angles.
Alan J. Bilanin's box-cavity, US PATENT # 4,682,808, filed, July 24, 1985, incorporated three captured-vortices in his ( top and both sides ), within rearward's facing 'steps'.