View Single Post
Old 02-03-2013, 05:29 PM   #28 (permalink)
Tesla
Master EcoModder
 
Join Date: Feb 2012
Location: Australia
Posts: 355

The Truck - '02 Nissan GU Patrol ST
Thanks: 5
Thanked 76 Times in 50 Posts
Quote:
Originally Posted by freebeard View Post
There's a Delete button too. Just sayin'.

And thanks for that video. I liked the real-world examples of things we would get simulations of today.



I get this in general, but:
  • What's a 'reverse template'? Why can't you see out of it?
  • What's an 'ellipsoid'. Is that like a Dymaxion shape?
Yeah, I know about the delete, but I figure leave well enough alone, something is a bit out of whack on my view.
Anyway

The vid was good, there are three more from the same guy, he's not bad in terms of presentation and helps me to get a handle on some of this stuff.

The reverse template is just that, swing it around 180° and use the pointy end as the front, only 15% worse drag than the right way around. The vision issue is when you place your windscreen at a 10-15° angle to horizontal, the distortion, refraction and internal reflection make it almost impossible to see out.

The elipsoid is just that, an elipse, highest point of camber at halfway point along the length and basically identical front and rear.

Aerohead is right in that the template profile is probably the most practical to apply to most existing vehicles, but understanding that the same Cd can be achieved with significantly different shapes suggests there is a lot more to take into consideration than just throwing a boat tail on everything.

As said elswhere, it is already hard enough for me to get into a std parking space without adding 50% more length to it, so I am drilling down, trying to understand the detail more and seeing how some of these factors may be applied more so to my vehicle.

Not suggesting this is a viable option, but if a reverse template can get within 85% of a full boattail, then it may be, in my case with a blunt, slightly rounded rear, that some attention modeled on a reverse template may allow me to gain some benefits without the excessive length penalty.
  Reply With Quote