I bring this concept up for discussion.
The idea is to use the centrifugal force to pump liquid. If the hose is filled with water and if it rotates at enough velocity, the centrifugal force acting on the liquid in hose, will make the liquid exit the hose at the open end and by doing so pumping water at the other end. Of course a certain velocity is needed to make it work as in the example below (which I have not calculated and depends on hose dimensions and how high the water has to be lifted...). The interesting part though, as always, is that disregarding friction, it should be possible to keep pumping water without adding energy for rotation, since the mass of the rotational device including water will always be the same.
Quote from: nybtorque on November 06, 2013, 05:51:57 AM
I bring this concept up for discussion.
The idea is to use the centrifugal force to pump liquid. If the hose is filled with water and if it rotates at enough velocity, the centrifugal force acting on the liquid in hose, will make the liquid exit the hose at the open end and by doing so pumping water at the other end. Of course a certain velocity is needed to make it work as in the example below (which I have not calculated and depends on hose dimensions and how high the water has to be lifted...). The interesting part though, as always, is that disregarding friction, it should be possible to keep pumping water without adding energy for rotation, since the mass of the rotational device including water will always be the same.
A rudimentary calculation suggests that if we have a 3/4" garden hose and if we swing it at a 1Hz frequency it will lift water in the hose >7m. So it will be more than enough for testing and very doable.
According to my unimportant opinion you have reinvented the centrifugal pump:
http://en.wikipedia.org/wiki/Centrifugal_pump
The centrifugal pump is not OU and one needs force to overcome gravity.
Greetings, Conrad
Quote from: conradelektro on November 06, 2013, 06:43:36 AM
According to my unimportant opinion you have reinvented the centrifugal pump:
http://en.wikipedia.org/wiki/Centrifugal_pump (http://en.wikipedia.org/wiki/Centrifugal_pump)
The centrifugal pump is not OU and one needs force to overcome gravity.
Greetings, Conrad
Thanks for your response Conrad. Of course I know about centrifugal pumps... and of course one needs force to overcome gravity... I'm sorry I didn't state that more clearly.
However, I still find it interesting to discuss the actual physics of the garden hose "impeller design". Especially I would like to know exactly what makes it unable to pump water the way I describe? Or, if it is possible, exactly what makes it harder to rotate the hose when water is pumped than when it is plugged?
Regards, NT