I have lowered the lift mass from 1000 g to 900 g.

Lift Mass = 900 g
Pressure Increase = (from 202 mm rise in input tube 'manometer') 20.2 g/cm²
Volume = 110 ml ( or cm³)
Stroke = 1.0 cm

This gives a comparative piston value of 110 cm³/1.0 cm = 110 cm².
At the measured volume that comparative piston would be able to lift 110 cm² x 20.2 g/cm² = 2220 g. 
Since my lift mass was only 1000 g this is underunity at 900/2220 = 40.5%.

However, not all of the recorded volume went into the ZED to cause the measured lift.  Approximately 14.4 ml (or cm³) was used to raise the pressure and remained in the input tube.  This caused the 202 mm rise in the input tube water levels between top and bottom of the stroke.  So if this 14.4 ml is subtracted from the 110 ml the comparative piston value would be 95.6 cm³/1.0 cm = 95.6 cm².  The calculated mass that comparative piston would be able to lift is 95.6 cm² x 20.2 g/cm² = 1930 g.  This is also underunity at 900/1930 = 46.6%.

M.

It's hard for me to see any dependence on geometry in those kinds of numbers. That is, if your Zed system were tall and skinny, or short and fat, the lift and pressure numbers would still be the same, since they depend on the volume of fluid, and this doesn't change regardless of the shape.
Am I correct in this reasoning?

Anyhow, did we ever get a confirmation that these results from the three builds (yours, wildew's and webby's) , can be modelled accurately by the sims that LarryC and see3d are working with?



Seriously, though.... it sure doesn't seem to me that you are going to be able to make progress towards the goal of confirming overunity in a simple three layer system that is clearly overunity by itself, unless you get some more specific help from someone who actually has such a system up and running.

By Wednesday.




Friday at the latest.

Quote from: TinselKoala on October 21, 2012, 03:09:38 PM
It's hard for me to see any dependence on geometry in those kinds of numbers. That is, if your Zed system were tall and skinny, or short and fat, the lift and pressure numbers would still be the same, since they depend on the volume of fluid, and this doesn't change regardless of the shape.
Am I correct in this reasoning?

Hi TK.

What I have observed with regards to the proportions of the Pod/Riser Diameter to Height is this:

A short setup (like mine) has a reduced stroke distance potential vs. a taller setup.  This is because the pressure differentials in the system are always escalating from whatever is your "preload" setup of water and air levels toward a "blow skirts" situation.  The shorter the Pod/Risers, the quicker you will blow skirts.  And so the maximum stroke potential is therefore reduced as the Pod/Risers are constructed shorter (relative to their diameter). 

So a taller build will give you more "distance" between the preload setup condition and when the system will "blow skirts."  Therefore the stroke distance increases as the ZED becomes taller.  To what limit this relationship converges and/or reverses I have no idea.

M.

Quote from: mondrasek on October 21, 2012, 04:01:04 PM
Hi TK.

What I have observed with regards to the proportions of the Pod/Riser Diameter to Height is this:

A short setup (like mine) has a reduced stroke distance potential vs. a taller setup.  This is because the pressure differentials in the system are always escalating from whatever is your "preload" setup of water and air levels toward a "blow skirts" situation.  The shorter the Pod/Risers, the quicker you will blow skirts.  And so the maximum stroke potential is therefore reduced as the Pod/Risers are constructed shorter (relative to their diameter). 

So a taller build will give you more "distance" between the preload setup condition and when the system will "blow skirts."  Therefore the stroke distance increases as the ZED becomes taller.  To what limit this relationship converges and/or reverses I have no idea.

M.

Isn't the calculation of a "comparative piston value" a way of normalizing or correcting for this difference in stroke length with Zed aspect ratio (ratio of diameter to height)?

Quote from: TinselKoala on October 21, 2012, 04:07:30 PM
Isn't the calculation of a "comparative piston value" a way of normalizing or correcting for this difference in stroke length with Zed aspect ratio (ratio of diameter to height)?

Hmmm.  Supposedly?   

But why rely on calculations when you can run a physical test?  I mean, it's the only way to be sure, right?

Any tests I can do besides these boring mass reduction runs that you think might help?

M.