Quote from: wildew on September 22, 2012, 08:06:48 PM
One thing I didn't see you measure - and I noticed because it's what I've been struggling with today.
Your funnel is well above the head line on the input tube, have you paid a lot of attention to the head values as measured on that tube? - Sorry if I missed it in the earlier posts.

'Morning Dale.  Yeah, I posted in the original data how the head changes in the input tube when the lift mass is added and removed.  I measured it roughly when at the sink location to be approximately 165 mm of input tube head change when the 1217 lift mass is removed or installed.  Also, the ZED lift itself changed 3.83 mm when that lift mass is removed or installed.  That was not pointed out or measured in the hurried video.

M.

Quote from: see3d on September 22, 2012, 08:53:20 PM
Mike, Very nice and clear video.  It makes it easier to understand your statements.  One thing to watch out for: When you add water to the funnel, it has one potential energy.  When you drain some water, it has a very much lower potential energy, even though it weighs the same.  You are adding energy into the system with your arm -- every time you take water out from below and add it to the funnel way above.  It is tricky.

Dennis, we've discussed that the entire way I vent water and reintroduce it is actually an energy neutral cycle.  This could be more clearly shown if I was using a reservoir with 74 grams of water instead of the funnel and raising and lowering that reservoir 10 mm.

In my system I am in fact adding energy to lift the water up from the vent height to the top of the water level (raising it past the top of the water to the top of the funnel does not matter since that energy is lost as the water falls back from that height to the surface of the water).  But I am also losing the pressure of the water at the vent location from the system when I vent the water.  That energy lost is equal to the energy I add to raise the water up, IINM.  So it should be energy neutral.

M.

Quote from: neptune on September 23, 2012, 07:42:30 AM
@Red_Sunset. Are you saying that a Zed where the risers can move independently of each other will give a better COP than a Zed where all the risers are fixed together sharing a common lid [flat top] ?

You will observe yourself that the outer layer lift area is only the horizontal rim between the risers where the u-bend and retainer are located. That area is not very big.
The central circular area of the pod is usually the biggest area if no specific changes have been done to change that ratio during the design stage.
Keep in mind also that the outer area is the top of the water column with the lowest pressure delta.

So, if you do not make special design changes at the start to distribute the area space between the layers, that is what you get. From my survey calculations, the total lift force will always be less than the stacked risers.

Michel

Quote from: TinselKoala on September 22, 2012, 10:03:43 PM
One question: in your video apparatus the input and output tubes are different. Is this necessary or just a matter of convenience? Are they plumbed to the same or equivalent pressure environments in the Zed?

The water input and output tubes are pieces of the same material.  6" is plumbed on the vent valve side.  The remainder (~66") is plumbed as the input with the Coke bottle funnel.  Both are attached to sides of a T-fitting on either ends of the horizontal or "top" line of the T.  The T is inverted and the vertical is glued into a hole in the center of the bottom of the ZED, so into the Pod chamber.

There is a separate smaller diameter air line that is only used during the setup.  It is also glued into a separate hole beside the one for the water line T-fitting.  So it also enters the bottom of the ZED into the Pod chamber.

Once the setup is complete, no air enters or leaves the system (except as being absorbed into the water and outgassing that way).  The particular setup that I showed in the video was completed three days earlier.  I have only cycled it by adding and venting water as shown in the video since then.  It has sat throughout the days and nights while supporting the preload and lift weight with no loss of anything except evaporation of some water from what I can tell.

My method for setting up is not precise as I have no accurate way to measure air volumes or pressures.  So I cannot repeat it except in the grossest ways.  It was achieved by holding the Pod/Risers down at the physical bottom position (Outer Riser resting on it's retainer wall) and then slowly adding water and air until the water rose up in the outer most chamber almost to the top of the Outer Riser and with the maximum amount of air in the system.  The maximum amount of air can be known when introducing more air causes it to bubble out of the Outer Riser and escape the system.  Once this is achieved the system was run through the cycle shown in the video over and over to make sure that more air did not need to leave the system (blown skirts) and that water in the outer chamber did not rise over the top of the Outer Riser.  The water in the outer chamber did require adjustment and water was removed from the outer chamber with an eye dropper until it's level remained below the top of the Outer Riser during the entire cycle.  It has since dropped slightly further due to evaporation over the past three days.

M.

mondrasek,

Your video link seems to be broken.
http://youtu.be/YwXsoqm75WY