Free Republic
Browse · Search
News/Activism
Topics · Post Article

To: cinFLA
Where did you come up with that outrageous conclusion?

I think that what they want to hear you say is that aircraft, ships, etc do not get "pushed" through the air, they get "pulled" through the air by the vacuum created forward of the proplusion regardless of the physical location of the propulsion unit on the craft in question.

At least, that's what I was taught. :-)
27 posted on 02/28/2003 3:50:59 PM PST by PatriotGames (AOOHGA! AOOHGA! CLEAR THE BRIDGE! DIVE! DIVE! WHOOSH!)
[ Post Reply | Private Reply | To 15 | View Replies ]


To: PatriotGames
Except that a vacuum can't "pull". All it does is refrain from pushing, therefore it fails to neutralize the push from the other direction.
28 posted on 02/28/2003 3:54:31 PM PST by inquest
[ Post Reply | Private Reply | To 27 | View Replies ]

To: PatriotGames
I think that what they want to hear you say is that aircraft, ships, etc do not get "pushed" through the air, they get "pulled" through the air by the vacuum created forward of the proplusion regardless of the physical location of the propulsion unit on the craft in question.

My understanding is that the propeller compresses the air behind it to a high presure while decompressing the air in front to a lower pressure. The propeller is then pushed forward bu the high pressure air behind it into the lower pressure in front of it. Same way a Wing lifts upward because of lower pressure on the top than the bottom. The way a physics teacher explained it and I've never found the need to investigat it further.

A 'Rocket', OTOH, works by having a high pressure in the chamber pressing on the front of the chamber pushing it forward (rear of chamber is open and has nothing for the combusting gasses to press against). Same way for a Jet since the front of the 'chamber' is closed by the high pressure intake air( easiest to visualize with a ramjet, pulse jets exempted). Either way, the author seems to either be trying to give an innacurate but understandable illustration of their operation to those ignorant of the operating principles or else he is basically ignorant of the principles himself and just inventing what he considers a plausible explanation. The explanation detracts from his credibility when talking about an esoteric subject like zero point.

39 posted on 02/28/2003 4:30:24 PM PST by templar
[ Post Reply | Private Reply | To 27 | View Replies ]

To: PatriotGames
I think that what they want to hear you say is that aircraft, ships, etc do not get "pushed" through the air, they get "pulled" through the air by the vacuum created forward of the proplusion

The propellor blades are slanted so that there is high pressure on the back of the blade and low pressure on the front. The difference, or net total force produces a thrust forward on the propellor. The vacuum on the front is limited to zero pressure, which is only 14 psi less than atmospheric. I would guess that the pressure increase on the back is more substantial.

50 posted on 02/28/2003 4:54:33 PM PST by mcsparkie
[ Post Reply | Private Reply | To 27 | View Replies ]

Free Republic
Browse · Search
News/Activism
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson