Mathematical Analysis of an Ideal ZED

[minnie]

   Koala,
           I guess Travis has "gone to ground" so to speak.
    That is what I imagined flow assist to be!
     Love listening to those crickets
                                        John.

[LarryC]

  Hi Larry,
            could you please explain what is meant by "flow assist".
    You show a stop to limit the travel, this would indicate that
    there is stored energy to be accounted for.
            Thankyou  John.

Hi John,

Flow assist is the input energy required above that supplied by the differential PSI between the 2 units.


Yes, there is stored energy.


Larry   

[LarryC]

The multiple connected columns require 1/3 the input Ft Lbs as the single column to have the same PSI.


Wouldn't it be great if someone could design a system to utilize and maintain the PSI in the multiple connected columns example.


Oops.

[MarkE]

The multiple connected columns require 1/3 the input Ft Lbs as the single column to have the same PSI.


Wouldn't it be great if someone could design a system to utilize and maintain the PSI in the multiple connected columns example.


Oops.

Oops is right Larry.  You miscomputed the input work.  Work is the integral of F*ds.  The initial force adding your 1ft of water is zero.  But the force at the end is:  4+1-2 = 3*0.65psi/ft.  The added work is therefore the integral evaluation from 0 to 1ft of:  0.5*3*0.65psi*area/ft*z² = 0.5*3*0.65psi*area/ft*1ft², which happens to be identically the difference between the starting and ending energies of:  E_INITIAL = 2*0.5*0.65psi*area*3ft² = 18*0.5*0.65*area and E_FINAL = 0.5*0.65psi*area*(1² + 2² +4²) = 0.5*0.65psi*area*21.

[LarryC]

Oops is right Larry.  You miscomputed the input work.  Work is the integral of F*ds.  The initial force adding your 1ft of water is zero.  But the force at the end is:  4+1-2 = 3*0.65psi/ft.  The added work is therefore the integral evaluation from 0 to 1ft of:  0.5*3*0.65psi*area/ft*z² = 0.5*3*0.65psi*area/ft*1ft², which happens to be identically the difference between the starting and ending energies of:  E_INITIAL = 2*0.5*0.65psi*area*3ft² = 18*0.5*0.65*area and E_FINAL = 0.5*0.65psi*area*(1² + 2² +4²) = 0.5*0.65psi*area*21.

MarkE,


Our Zed spreadsheet output formulas are F*ds as Force * Stroke. The input Ft Lbs formulas use P average * Volume of the fluid moving into the Pod retainer. That also increases the head in the risers.


The pressure rises faster than would account for just the input volume height, due to the riser head change. Are you now saying we have to account for the riser head change? That would be double dipping as its already factored in P average.


Larry