How A Radial Engine Works

Discussion of all things technological and/or gadgety
User avatar
Darrell
Posts: 6586
Joined: Mon Aug 18, 2008 11:12 pm

How A Radial Engine Works

Post by Darrell »

Parts 1 & 2:

https://www.youtube.com/watch?v=qjnQKXNPsk4

https://www.youtube.com/watch?v=R71Xhrkc3EQ

Fascinating! Seems like it would produce a lot of torque. Shamelessly stolen from an arfcom thread. 8-)
Eppur si muove--Galileo
User avatar
JustinR
Posts: 1852
Joined: Tue Aug 19, 2008 2:53 am

Re: How A Radial Engine Works

Post by JustinR »

That is awesome. I mostly understood the concepts from my reading, but I am a visual learner and that helps to put it together. Thanks for sharing.
"The armory was even better. Above the door was a sign: You dream, we build." -Mark Owen, No Easy Day

"My assault weapon won't be 'illegal,' it will be 'undocumented.'" -KL
User avatar
mekender
Posts: 13189
Joined: Tue Aug 19, 2008 9:31 pm

Re: How A Radial Engine Works

Post by mekender »

Certainly interesting, I had always thought that the outer part with the pistons was what rotated.
“I no longer need to run as a Presidential Candidate for the Socialist Party. The Democrat Party has adopted our platform.” - Norman Thomas, a six time candidate for president for the Socialist Party, 1944
User avatar
Captain Wheelgun
Posts: 1123
Joined: Tue Aug 19, 2008 2:31 am
Contact:

Re: How A Radial Engine Works

Post by Captain Wheelgun »

mekender wrote:Certainly interesting, I had always thought that the outer part with the pistons was what rotated.
Nope, that's a Rotary engine (not to be confused with a Wankel engine). Rotaries are what you saw on most of the WW1 fighters. A lot of the mechanism is the same, but a rotary has the crankshaft bolted to the airplane and the propeller bolted to the crankcase, which turned with the cylinders. This allowed for adequate cooling at very low airspeeds, but was apparently a pain in the behind to throttle and has massive gyroscopic torque.
"What is this, the Congress Avenue Independence Day Parade?" - Capt. Karl von Stahlberg, RTN
Republic of Texas Navy Archives
tfbncc
Posts: 895
Joined: Tue Aug 19, 2008 2:00 am

Re: How A Radial Engine Works

Post by tfbncc »

Certainly interesting, I had always thought that the outer part with the pistons was what rotated.
Well, you're not completely wrong. The Fokker DR1 Triplane used a rotary engine that the cylinders spun and the crank shaft was stationary. The major problem with this was that there was no throttle control. It was either on or off. The pilot slowed the airplane down by switching off the magnetos momentarily until he reached his desired speed. Not very efficient and it was one of the leading causes why the DR1 was replaced by the DR7 as the frontline scout of WWI
User avatar
blackeagle603
Posts: 9770
Joined: Tue Aug 19, 2008 4:13 am

Re: How A Radial Engine Works

Post by blackeagle603 »

Yeah, word is that with a rotary if you want to turn left you're better off making a 270 to the right. Those were fed a fuel/oil mix thru the crankshaft (to deal with fuel delivery/plumbing challenge I imagine). Forget your dry sump, those were total loss oilers.
"The Guncounter: More fun than a barrel of tattooed knife-fighting chain-smoking monkey butlers with drinking problems and excessive gambling debts!"

"The right of the citizens to keep and bear arms has justly been considered, as the palladium of the liberties of a republic;" Justice Story
User avatar
blackeagle603
Posts: 9770
Joined: Tue Aug 19, 2008 4:13 am

Re: How A Radial Engine Works

Post by blackeagle603 »

Interesting wiki on rotaries here: https://en.wikipedia.org/wiki/Rotary_engine
"The Guncounter: More fun than a barrel of tattooed knife-fighting chain-smoking monkey butlers with drinking problems and excessive gambling debts!"

"The right of the citizens to keep and bear arms has justly been considered, as the palladium of the liberties of a republic;" Justice Story
Greg
Posts: 8486
Joined: Tue Aug 19, 2008 2:15 pm

Re: How A Radial Engine Works

Post by Greg »

Captain Wheelgun wrote:
mekender wrote:Certainly interesting, I had always thought that the outer part with the pistons was what rotated.
Nope, that's a Rotary engine (not to be confused with a Wankel engine). Rotaries are what you saw on most of the WW1 fighters. A lot of the mechanism is the same, but a rotary has the crankshaft bolted to the airplane and the propeller bolted to the crankcase, which turned with the cylinders. This allowed for adequate cooling at very low airspeeds, but was apparently a pain in the behind to throttle and has massive gyroscopic torque.
Apparently there were a few different ways to modulate power output, but none of them was particularly satisfactory.

Also getting fuel and air into the cylinders is an issue, requiring the crankcase to serve as intake manifold. That has problematic consequences of its own, oil loss being only one of them.

Just as a side note, rotary engines are spectacularly loud for their power output.
Maybe we're just jaded, but your villainy is not particularly impressive. -Ennesby

If you know what you're doing, you're not learning anything. -Unknown
Sanity is the process by which you continually adjust your beliefs so they are predictively sound. -esr
User avatar
mekender
Posts: 13189
Joined: Tue Aug 19, 2008 9:31 pm

Re: How A Radial Engine Works

Post by mekender »

blackeagle603 wrote:Interesting wiki on rotaries here: https://en.wikipedia.org/wiki/Rotary_engine
The animation on the right is what I remember seeing years ago that made me think that radials were like that... I never put 2 and 2 together to realize they were different designs.

Thinking about it logically for a split second, it makes total sense to do it the radial way, but it was not something I had ever really given a ton of thought to.

And I believe that there were some cars that had a rotary engine too...
“I no longer need to run as a Presidential Candidate for the Socialist Party. The Democrat Party has adopted our platform.” - Norman Thomas, a six time candidate for president for the Socialist Party, 1944
User avatar
randy
Posts: 8334
Joined: Wed Aug 13, 2008 11:33 pm
Location: EM79VQ

Re: How A Radial Engine Works

Post by randy »

mekender wrote:And I believe that there were some cars that had a rotary engine too...
"...but the Mazda goes mmm..."
...even before I read MHI, my response to seeing a poster for the stars of the latest Twilight movies was "I see 2 targets and a collaborator".
Post Reply