Warplane - Rotary Engine Centrifugal Force

An excerpt from part 1 of the PBS 4-part special Warplane.

Category:

Education

Tags:

• rotary
• engine
• centrifugal
• centrifuge
• airplane
• plane
• Warplane
• PBS

[Oshyrath]

that's great but there is no such thing as centrifugal force.

[HappyGuyxlii]

Centripetal?

[Squarerig]

As an old seafarer I am familiar with "gyroscopic precession" on gyro compasses but to have to compensate for this when taking off must have been a frightening situation indeed!

[akfox38]

@mswinman

You're not missing anything. When they first show the gyroscope w/o the plane attached to the front they referenced it incorrectly by overshadowing the airplane in the wrong direction with the nose pointing out. When the guy actually attached the airplane with nose pointing in to the gyro the prop of the plane and the gyro are both indeed turning clockwise from that frame of reference which is correct.

[mswinman]

@GGigabiteM Ok, thanks for that, for some reason I thought the direction of rotation was as viewed from the cockpit. Isn't the rotation on the gyroscope the same as the aircraft? It looks the same and it certainly does what they say it would do, maybe I'm missing something.

[GGigabiteM]

@mswinman There was one notable engine that spun both ways, the Siemens Halske SH.III, which used beveled gears on the back of the engine to have the crank case spin counter-clockwise at 900 rpm, and the pistons, connecting rods and crank shaft spin clockwise at 900 rpm.

Many other types were also usually the conventional counter-clockwise, though there were notable exceptions like Mercedes, BMW, Bristol and some Rolls-Royce engines.

[GGigabiteM]

@mswinman Because most Rotary engine designs from just before the turn of the century up until the end of WWI were only made by a handful of manufacturers (Clerget, Bentley, Gnome, Oberusel) and they all rotated counter-clockwise. There were also dozens of companies that licensed engine designs from these major firms and they all rotated the same way.

There may have been some one off engines made by inventors that spun clockwise, but none that made it into mass production.

[mswinman]

@GGigabiteM Why do you say all rotary engine rotate counter-clockwise?

[8literbeater]

It's called gyroscopic precession, for those that care to investigate. I'm surprised they didn't mention that on the show. It's now required knowledge to get a pilot's license, even though modern engines aren't as bad as those old ones.

[Sadetree]

Interesting