Date:         Wed, 2 Nov 1994 19:04:10 -0800 (PST)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         H Steven Dolan <dworkin@netcom.com>
Subject:      RE: mpg enhancements

On Wed, 2 Nov 1994, Jan Allbright wrote:

> > Bill Kennedy asks:

> > A long time ago, there was a thread about how you could convert a
> > snub-nosed air-pusher like our vans into a sleek TGV/Bullet Train
> > aerodynamic wonder. 

Never delete anything.  Last night, I cleaned out my back e-mail files 
and deleted this exact thread.  Damn!
 
> > Someone posted that you could take a cone of suitable size, put it on
> > a pole of suitable length, and stick it to the front of the van (like
> > the knights of old).  This gives the same drag coefficient as a solid
> > mass of the same length, but with a nice bullet nose.  I'm pretty sure
> > there's even some scanned photos of drawings of someone's research
> > that "proved" that putting a more rounded nose on a bus drops its
> > coefficient of drag dramatically on the vanagon web homepage. 

That would be me.  The idea came from an article on improving the range 
of sub launched missiles.  The propellent charge is limited by the length 
and diameter of the launch tube (built in to the sub) and by minimum 
warhead size.  The only way was to improve the aerodynamics was to 
increase the length of the missile (impossible without rebuilding the 
sub).  So what they did was build in an extensible probe on the nose 
which came out after launch and increased the effective aerodynamic 
length of the missile, which reduced drag.  

BTW, which WWW page? The one @ Automatrix?

> > Anyway, lately I've been thinking about putting that pole with a plate
> > or cone on the end on my van's nose, and see how fast I can go.  Right
> > now, wind drag increases as I approach 90mph.  I don't think I've been
> > above 90 (maybe on a downhill?)

> > -Jim

> On this same though ... all you really need is a pole with a small cone
> on it's tip. The purpose is to _bend_ the airflow above and around
> the rather _un_ areo shape of the bus nose..old jet fighters use
> to have these "probes" on their nose to punch through the air...
> 
> size and configuration of the pole and small cone left to student 8) 

No, no, I was a philosophy major!  Not an engineer!  Please, Please, how 
big a disk? with what profile? (I assume an ogive with edges tangent to 
the front corners of the bus, but ???) how far out from the front? TIA

					H Steven Dolan
					dworkin@netcom.com