D'Ectol's oscillating column cycles through changes in the water while its solid parts remain fixed. Explore Brown's description of cone formation, checked flow and release, then compare supplied and assumed lifted water volumes.
Water-Volume Comparison Calculator
Enter a declared supply rate, observation time and assumed lifted fraction. The worksheet divides the entered supply volume arithmetically; the lifted fraction is not predicted by the historical mechanism or the animation.
Equation Used
- Supply rate and observation time are nonnegative declared averages.
- Lifted fraction is a user-declared percentage between zero and 100, not a calculated efficiency.
- One litre is used only as a volume unit; density, mass, pressure, head and energy are not calculated.
- Tube dimensions, plate spacing, jet shape, cone stability, cycle period, losses, priming, discharge conditions, fabrication and safety are excluded.
The tubes and plate remain fixed while the water state changes. The calculator divides an entered supply volume into assumed lifted and remaining portions independently of the illustrative animation.
Four stages repeat while every machine part remains fixed
Brown's movements 445 and 446 describe a smaller upper tube, continuously supplied with water, above a larger lower tube. A circular plate is placed below and concentric with the lower opening.
Descending water gradually forms a cone on the plate. As that cone protrudes into the smaller tube it checks the downward flow. Continued supply raises the upper water column until the cone gives way; discharge resumes and the sequence repeats. Brown says the periodic action is regulated by the water supply.
A historical fixed-part water-lifting concept
Brown identifies the device as D'Ectol's oscillating column for elevating a portion of a given fall of water above the reservoir or head while all machine parts remain fixed. The source does not establish a universal geometry, lifted fraction, delivery head, efficiency or commercial application.
The changing water state provides the periodic action; no rotating crank or moving mechanical column is part of this arrangement.
Water-volume relationships
Q is the declared average supply rate, t is the declared observation time and f is a user-entered lifted fraction. No term is derived from tube or plate geometry.
Water-volume example
For Q=60 L/min, t=10 min and f=20%, the declared supplied volume is 600.0 L, the declared lifted portion is 120.0 L, the remaining portion is 480.0 L and the lifted/supplied ratio is 0.200.
This does not claim that D'Ectol's device lifts 20% under any physical conditions.
Hydraulic performance beyond the volume calculation
Brown supplies a qualitative operating sequence, not dimensions or a performance model. The animation therefore keeps the tubes and plate fixed and uses phase only to explain cone formation, flow checking, upper-column rise and release.
Predicting actual lift or timing would require a hydraulic model with tube dimensions, supply conditions and discharge conditions. The entered lifted fraction is an assumption rather than a result of such a model.
Oscillating-column questions
What oscillates if all the parts are fixed?
The water state cycles: cone formation checks flow, the upper column rises, and the cone gives way.
Does the calculator predict the lifted fraction?
No. It is a declared input.
Does the animation predict cycle frequency?
No.
Is this an oscillating-water-column wave-energy model?
No.
Can this size or build the historical device?
No.
Primary historical reference
- Henry T. Brown, Five Hundred and Seven Mechanical Movements, movements 445-446: primary public-domain figure and description of D'Ectol's oscillating column, its two tubes, circular plate, water cone, checked flow, rising upper column and periodic release.
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