Not exactly. The theory is that a certain amount of air enters the
GRILL but its 'path of least resistance' is actually downward through
the opening to the ground between the grill and radiator. This
reduces the amount of air rammed through the radiator signifigantly
and therefor allows backflow (recirculation) from the engine
compartment to percolate forward through some of the radiator, thereby
reducing its efficiency in removing heat.
It's conjectural (but not proven as far as I know) that the downward
exhausting of the air between the grill and the radiator can actually
draw (induction due to negative pressure differential) the air forward
through the radiator.
Consider also that with the curved grill and a bumper out front, there
is a certain amount of deflection of the air along the body line
rather than straight into the grill. The 'shadow' of the deflection
off the bumper is right where the grill is so the amount of air
actually entering the grill is less than it might be.
The Triumph fan blade (two pieces of steel with a hint of twist to
them) doesn't draw much and has enough gap to the radiator that it can
have signifigant bypass flow. Thats why the addition of an electric
fan that is intimate to the front of the radiator can be very
effective.
A useful piece of data when trying alternatives is to take the
temperature measurement of the coolant at the top and the bottom of
the radiator (or at least the surface temperature of the top and
bottom tanks) and see what produces the biggest temperature drop AND
the lowest bottom tank temperature.
A 1925 Franklin I owned many years ago had plates that sealed the
engine compartment from the road so all air entered through the
cooling fan in the front and exited around the transmission. This was
critical since it was an air-cooled in-line 6 engine. Earlier
Franklins had fans at the back to draw the air out. No louvers were
used from 1923 to 1929 and after that they were for style more than
effect.
EPaul21988@aol.com wrote:
>
> In a message dated 5/31/100 1:08:29 PM EST, stuross@nac.net writes:
>
> << He discovered that the air doesn't come out through the
> louvers. In fact, it recirculated back through the radiator. >>
>
> Am I understanding this? So at, say 60MPH, the air forced through the
> radiator into the engine compartment is recirculating and coming back out the
> radiator against the 60mph force of the air coming in, but none comes out
> through the louvers? .
--
"Entropy Happens!"
Michael D. Miles, PE Consulting Design Engineer
(503) 292-1234, FAX: (503) 292-1105
email: mdmiles@mdmpe.com
http://www.mdmpe.com/
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