Hydro Differential pressure exchange over unity system.

[fletcher]

MT .. I check over your spreadsheet this morning - doesn't look like Red is going to comment further.

IMO there are a couple of errors & suggestions for you to consider in your analysis.

1. if you covert the pipe entry area to the same as the precharge area the flow rates match, which makes things easier to see - that means the pipe diameter would be around 0.199m^2

2. the Work Output capability of the Pod with a stroke of 0.1 m is NOT what you calculated IMO - you have calculated the entire Pod Volume & converted it to Kg weight water equivalent, then taken a 10th slice of that weight to match your stroke & iteration increments of 0.1 m & 10 - then you have calculated your Output in kgm based on that 10th weight slice acting over 0.1 m stroke distance.

The actual buoyancy potential Work Output is the volume weight of the precharge [28 kg] over 0.1 m stroke length, IINM - not the Pod volume, therefore substantially less than your spreadsheet predicts for COP.

You would also need to assign some mass to the Pod itself to find a Net Upthrust.

That's how it appears to me after a quick peek.

[GreenHiker]

Wildew -

Nice Set up!

Thanks for the video - it is crystal clear now what you were describing.
It's great you are reporting what you are seeing even if it was due to the leak.

Looking forward to seeing more layers!

Tom

[fletcher]

MT .. the invisible pod - a cross-sectional view of a hypothetical representation Marcel.

The reference frame is changed - 'g' set to 10 m/s^2 for clarity.

[fletcher]

I obviously never have a case where the pod is completely submerged.  It is always partially out of the water.  For a zero layer system, the force seems to be linear with the height of the water column.

If i visualize a teeter-toter with two buckets on each side filled with water so that they are in balance and at the same level. how much force (or extra water) will it take to move one side down 10 degrees? 
The answer is not much.  That is my principle.

However, if suspended right at the waterline in each bucket is a water filled float (neutral buoyancy), taking up half the total water area and zero volume when level, then how will that change the amount of force required?

Interestingly Dennis I simed & built something very similar about 7 years ago - when the float is in the bucket fluid the forces move the bucket down to create separation distance between the float & the bottom of the bucket.

You can try it easily with a beaker on a scale - just push one finger down into the water.

P.S. although I have a pic saved of the sim from those experiments the sim itself was lost in a hard drive crash a few years ago & I never bothered to recreate it again.

[TinselKoala]

Ahah!  A flash of insight, brought on by the three posts above. Thanks, fellows!

The insight is this: regular floating buoyancy behaviour depends on the mass as well as the displacement. If the mass of the floater is greater than the mass of the displaced water, the floater sinks, although the part of its weight that is equal to the water is cancelled by the buoyancy. And if you have the chamber sitting on the scale, the total weight includes the entire mass of the floater, whether it's sunk, floating, or resting on top of the container, as long as it's "internally restrained" or not restrained, just floating.
But.... when the floater is _externally restrained_, or pushed into the water while attached to some external support, inverted Travis Effect style.... then the scale only indicates the chamber plus the weight of the displaced water. The mass of the floater itself is not included. It could be made of solid lead or perfectly weightless, the scale is still only going to read the same thing: the weight of the displaced water, because the weight of the floater itself is supported by the external restraint.

Hmmm.... interesting, but is it relevant to the behaviour of a Zed or a pair of them? Something to think about anyway.