Gravity Mill - any comments to this idea?

[hartiberlin]

hi stefan,

thanks for posting my picture.  any idea why it wouldn't work for me?  and thanks for the explantion (still don't know what all that means).  if i ever need to use it, i'll call you.

You must click the Reply button,
do not use the Quick-Reply ,
then you can also attach a picture file.

i was trying to find out how much 1 cubic foot of lead weighs.  couldn't find anything i really understood, but did find the atomic weight of lead and water.  lead= 207.2  water=18  does that mean for the same volume lead would be 11.5 times heavier

Yes, 11.5 times heavier ! That?s a lot ! Now you see, why they use it for fishing
as a weight...

[hartiberlin]

Did somebody else already try, how high
the water can be pressed through a small diameter
exit pipe ?
In my experiment, where I only had a pretty slippery
shuttle, the pressure from the buoyant force was not very big
and thus it did not go very high in a smaller pipe at the top....

I wonder, if the shuttle must not be this high itsself
as high as the exit pipe will be ?

Maybe I just need a tighter fitted shuttle to see how high I can bring
up the water in the exit pipe and I also have to get a much longer main
pipe to play with it....

TBird, what did you see in your experiments ?
Did you try already a smaller exit pipe ontop the main pipe ?

Regards, Stefan.

[ooandioo]

Hi all.

No reply from Mr. Herring yet.

prajna, very good and clearly laid out job. I think we now should discuss the way the shuttle should look like. As stefan allready mentioned, compressing the shuttle via leverage will cost more energy then via air pressure - i agree with that.
Perhaps we should come back to pranjas design.

Andi.

[2tiger]

Hello all
Yesterday I tried the same experiment as you Stefan.
This time with a higher tube (1m High) from the boxing of a Barbiefamily from my daughter and a plastic Cokebottle as a swimmer. I tried both with seal and without, even with valve like function on the upper and lower side of the tube. Tomorrow I will post a photo from my setup. In all cases there was no water lifted up! The water level was always the same. Nor a mm difference.

So 2day I was reviewing your video and saw the difference between yours and my experiment.
I attached a drawing and I hope you all will understand what I?m talking about.

Picture No. 3 is the most important one. It shows that your swimmer body lifted also the tube up, perhaps caused by fiction of the water between the tube and the swimerbody, and that your swimmerbody didn?t reach his whole level as in the startposition.
I assume that the weight of water you "lifted" plus the weight of the tube is equal to bouyancy force of the swimmerbody. So in that moment the setup is in balance. But now we have to understand why the water stands there "lifted". Will it stands there forever?? I think that it won?t!  
Stefan - please try again your experiment and wait a few minutes after the water is lifted. As result I expect that it will flow out between the tube and the body, as long you have no seal there. Or that the tube will slide slowly down and let the water flow out at the upper border of the tube.

If I do my homeworks right noone reported that the tube in the E.L.S.A.setup is a moving part. In the most graphics it is a fixed part, or am I wrong? Otherwise the shuttle have to lift up the hole watercolum and tube against gravity.

This is very important for your experiment Stefan, because when you fix your tube in anykind on the ground, you will not see the same result. Please try again and you will see I?m right.

by
2Tiger

[pese]

http://www.grc.nasa.gov/WWW/K-12/WindTunnel/Activities/buoy_Archimedes.html