View Single Post
Old 11-04-2009, 03:35 AM   #8 (permalink)
Frank Lee
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,762

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,585
Thanked 3,555 Times in 2,218 Posts
Quote:
Originally Posted by SentraSE-R View Post
From my experience in smaller propeller planes, they do operate at best BSFC all the time after takeoff is completed.
You made the key point right there.

There's no need for "pulse" as we think of it in automotive terms cuz cruise loads a/c engines accordingly for the duration.

That is another reason why you generally can't just pluck an automotive engine out of a car and stick it into an aircraft. The duty cycles are waaay different, with the auto engine loafing along most of it's life with brief periods of higher load, and the a/c engine working pretty hard most of it's life, with brief periods of even higher load. That's why we ought not laugh too hard at an a/c engine that uses, say, 330 cubic inches to put out 100 hp. It's not because the engineers were dense.

There are motorized gliders that I suppose could be considered "pulse-and-glider(ers). They aren't in it for the fe though. They are mostly for recreation- not seriously trying to get from a to b- and the motor gets the tow plane out of the equation and allows for more thermals-hunting per mission anyway.
__________________


  Reply With Quote
The Following User Says Thank You to Frank Lee For This Useful Post:
user removed (11-04-2009)