What Mathematical Principles Govern the Functioning of Water Clocks?

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Discussion Overview

The discussion centers on the mathematical principles governing the functioning of water clocks, particularly focusing on the role of the float mechanism and the implications of its absence. Participants explore theoretical and mathematical aspects related to flow regulation and control systems.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant notes the self-regulating ability of the water clock, attributed to the float mechanism.
  • Another participant suggests that the cone-shaped float changes the effective flow area of the supply line, likening it to modern flow regulators and recommending the Bernoulli Equation as a starting point for analysis.
  • A request is made for assistance in deriving the fluctuation of height without the float, framing it as a control problem.
  • One participant expresses inability to assist with the math but assumes that the absence of the float would lead to overflow.
  • Another participant characterizes the situation as a differential equation problem, stating that the rate of flow in is constant while the rate of flow out depends on height, indicating that height is influenced by geometry and flow rates.

Areas of Agreement / Disagreement

Participants express differing views on the implications of the float's absence, with some focusing on the mathematical modeling aspects while others emphasize the practical consequences of overflow. The discussion remains unresolved regarding the specific mathematical derivations and implications.

Contextual Notes

There are limitations in the discussion regarding assumptions about flow rates and the geometry of the water clock, as well as the lack of detailed mathematical steps in deriving the height fluctuations.

hanson
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Hi all!
I'm finding information about the ancient time counting machine --- water clock, as shown in the figure.
I know that the water clock invented by Ktesibios has a self-regulating ability. This is achieved by a float.
Anyone got more information about the mathematics involved?
 

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Since it is a cone shaped level float, the level changes the effective flow area of the supply line coming into the tank. This is exactly the same principle as a modern day flow regulator.

The Bernoulli Equation would be an appropriate place to start looking.
 
can anyone help to derive the fluctuation of height h, if the float is absent? This is a typical control problem I suppose.
 
Can't help with the math... sorry. I assume, however, that since the float is there to keep the tank from overflowing, that's exactly what would happen if it wasn't there.
 
Looks like just a differential equation problem to me. There is no control system if the float is removed.

Rate of flow IN is constant (if the inlet is always above the surface of the water). Rate of flow OUT is a function of height. So the height is a function of geometry and the two flows.
 

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