Is it a "rocket engine" or a "rocket motor?"

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You might want to rethink that… If the above were true, then I could put an Internal combustion engine in a large oven and turn up the heat in the oven and expect work to be produced by the engine; which isn't true.
Examples of heat engines would be a refrigerator and to some extent, a diesel engine, as the heat in a diesel engine starts the combustion of the fuel which in turn causes work to be done.

First of all, I didn't think that. I cited a reference that thought that.

The first part of the Spark Notes description was that a "heat engine is a machine." If the machine is not configured to be powered by external heat, then it won't work, but that doesn't mean the concept is wrong. Also don't be trapped by the notion that engines can only be internal combustion. There are viable external combustion engines (steam engines, Stirling engines) where an oven could conceivably be configured to be the heat source. ICE's are more dominant because they tend to be more efficient.

A refrigerator uses a motor to compress the gas. Not sure it fits the description of "engine" but a diesel engine definitely does.
 
Steam-ENGINE.
Electric-MOTOR.
Does this help any?

Indianapolis Engine Speedway.
Engine Trend Magazine.

And in a similar vein; is it a “Switch” or a “Turnout”? Model Railroad enthusiasts know of what I’m referring to.
 
All well and good, but what do you use to "make them go"? - starters, igniters, or lighters?

s6
 
Frank Malina called the solid rocket engines they developed as part of the GALCIT program "motors" to distinguish from Goddards' engines and the name stuck.

Also the egg came before the chicken.
 
CTI and Aerotech call them motors... I don't care how Estes call them.
 
By whatever name you call them, they're 40% off with the coupon at Hobby Lobby. :wink:
 
If it says so on the "Internet" .....then it must be true.....and on and on it goes.:pop:
 
Lighter, woosh releaser, or that #$%&*( $%&* that won't #$%& light the %^&$&$ eng-otor (or motengor)...
 
thanks everyone for having fun with this. I love these responses.
 
I dunno, I kinda like "rocket gin" (referring to that ARS piece that explained how the cotton gin got its name).
 
Dad developed the propellant for the first stage of the Minuteman and the Trident. He called them motors. That's good enough for me.

Joe


Sent from my iPad using Rocketry Forum
 
In a rocket motor, it's the expanding gasses that produce the work, heat is a byproduct of the reaction (combustion) of the fuel. I don't know if you remember the old "Coldpower" rockets, but they used freon as the "fuel". The " coldpower" motor was a tank of compressed freon, and when it was discharged out of the nozzle, the freon expanded which caused thrust. No heat involved.

I guess in a pure physics context, they would be considered "heat engines" as there is a temperature differential in all these devices, but it's the expansion of gas from a chemical reaction that does the work.
No heat involved for the coldpower Rocket? None produced perhaps but certainly heat was involved as the liquid freon expanded.
It really doesn't matter whether we call them motors or engines.
 
Which is wrong, all due respect to Mr. Estes.

later! OL JR :)

PS... see what you've started!!!!

*Started*?!?!?!? This thing has a 'starting point'???

Look, there are two things that happened 13.8 billion years ago:

1) The Big Bang;

2) The debate on 'motors' vs 'engines'.

Next, they'll be debating about which drifts less:

A) A conventional circular canopy;

B) A rock.

<g>

-- john.
 
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