Cooling

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Revision as of 10:23, 14 October 2022 by Apm (Talk | contribs) (Taking cooling to its limit: added new section === Cooling by capsule transport & its optimization ===)

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Cooling is both relevant in both

  • mundane and important practical systems and
  • especially in systems that aim to go to the absolute limits of what is possible

The latter by nature goes in quite speculative territory as
it's not very compatible with conservative estimation and explotratory engineering.

Practical cooling in gem-gum factories

Heat that needs to be removed originates from:

  • dissipation from (more or less intentional) snapping instabilities
  • more subtle inefficiencies in piezomechanosynthesis
  • frictive dissipation – Only partly recuperable by heat engine due to conversion of free energy into bound energy.
  • squeeze-out of entropy – heat from moving disorder in positional space to disorder in impulse space (aka heat) (fully recuperable)

Temperatures to cool to:
For reliability of piezomechanosynthesis lower is better.
Below some point there are diminishing returns though.
Optimal might likely be somewhere around liquid nitrogen. Maybe a bit lower.
Room-temperature works bit is a bit too high for good reliability.
Liquid helium temperatures are likely overkill.

Anticooling:
To get the energy back that was invested to cool below room temperature and
to not freeze clean room air in further up assembly levels
the so far assembled parts-fragments need to be warmed up again before proceeding to higher assembly levels that
no longer involve (unguided) aligning of atomic bonds.
Basically one needs to recuperatethe cooling energy by heat engine.

Given layer geometry of assembly level (assembly layers) as a possible self suggesting geometry
cooling and anticooling forms a "cooling sandwich".
From an surface to volume ratio this thin layer sandwich geometry is far from optional.
Maybe hinting on that an other more batch processing
and serializing in-between geometry might be worth considering.
Increasing fast track transport distances increases frictive losses though so its a tradeoff optimization.
Also depending on how efficient piezomechanosynthesis can be made as it likely dominates over frictive losses.

(TODO: Investigate possible assembly level geometries taking this into account too.)

Taking cooling to its limit

Warning! you are moving into more speculative areas.

Application cases may include:

Strategies that could be employed include:

  • Choice of best materials as the thermal mass (this is beyond metamaterial emulatability)
  • Choice of best materials as the thermal conductors (this is beyond metamaterial emulatability)
  • Choice of best materials for applying eventual tricks (this is beyond metamaterial emulatability)
  • Thermal mass capsules transported on tracks providing good thermal contact.
  • Trick: Active squeeze-out of degrees of freedom from the perspective of the equipartitioning theorem

(wiki-TODO: discuss these in detail)

Cooling by capsule transport & its optimization

Thermal energy transport via heat conduction can be very fast.
Especially across short distances. But longer macroscale distances is slows down. Nonlinearly.
One way to counter that is to physically transport thermal masses.
There are some interesting tradeoffs/optimizations to make.
Thus there should be:

  • some optimal cooling transport speed depending on details of design choices.
  • some optimal scale of thermal-mass-transport-capsules

Optimizing speed:

  • PRO: Higher speed means faster heat removal. Trivial.
  • CON: Speeding up to high speeds means higher dissipative losses from (wearless) friction
    leading to even more heat needing removal.
    Unfortunately very low friction suspension (like means of levitation) are not an option at the hot side
    due to them providing insufficient thermal contact.

Optimizing scale:

  • PRO: Bigger thermal-mass-capsules means less thermally conductive bearing area per thermal mass
  • CON: Bigger thermal-mass-capsules means (nonlinear) increase in charge-up-time of these capsules

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