forgot the trailer..
mayf
----- Original Message -----
From: "DrMayf" <drmayf@teknett.com>
To: "Dave Dahlgren" <ddahlgren@snet.net>; "john robinson"
<john@engr.wisc.edu>
Cc: <land-speed@autox.team.net>
Sent: Thursday, October 23, 2003 11:02 AM
Subject: Re: aero
> Our text says that a cooling system drag coefficient was worth about 0.025
>
> mayf
> From: "Dave Dahlgren" <ddahlgren@snet.net>
> To: "john robinson" <john@engr.wisc.edu>
> Cc: <land-speed@autox.team.net>
> Sent: Thursday, October 23, 2003 7:31 AM
> Subject: Re: aero
>
>
> > What is the CdA of the fairing section vs. the CdA of the duct?? The
math
> ought
> > to be simple at that point.. I would suspect that the fairing is an
order
> of
> > magnitude better than the duct.
> > Dave
> >
> > john robinson wrote:
> > >
> > >
> > > Concerning the fairing ( or car body), most of the ones I have
> > > seen, seem to be solid to the air, in other words they don't allow the
> air
> > > to enter the >inside< of the fairing/body, only direct the air around
on
> > > the outside. Now I know that there is an energy penalty from having
air
> to
> > > flow through a "dirty" enclosure, but would the bike/car benefit from
> > > having a slightly smaller frontal area due to the air passing through
> the
> > > bike/car rather than around it? could this internal air help to
> partially
> > > fill the vacuum bubble behind the vehicle thereby reducing drag? would
> the
> > > reduction of drag be greater than the drag from the ducting? should
the
> > > internal airflows be more "directed" by enclosing them with ducting
and
> > > thereby cleaning up the internal airflows or is there enough benefit
> from a
> > > reduction of frontal area that there is no need for the ducting?
> > > I realize that cars are going to have more of a problem with
> doing
> > > an internal duct, due to the length, but motorcycles being shorter
might
> be
> > > helped.....I'm thinking of the P-51 radiator that made thrust from the
> > > added heat from the radiator and the shape of the ducting. this might
be
> of
> > > some use to me with an aircooled bike.....
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