raw · papers · ingested 2026-07-19
Heat and mass transfer for a small diameter thermosyphon with low fill ratio
Source: https://www.sciencedirect.com/science/article/pii/S2666202719300102
Authors: Robinson, Smith, Hughes, Filippeschi. International Journal of Thermofluids, 2019 (exact publication day not independently confirmed).
Key findings
An 8mm-diameter, water-charged thermosiphon with a 25% fill ratio and a 200mm evaporator length, studied via high-speed video flow-pattern visualization. Heat and mass transport at lower heat fluxes was dominated by geyser-type boiling with correspondingly low heat transfer coefficients. Central conclusion: as tube diameter shrinks, tube-wall/working-fluid interactions — friction and surface tension — become progressively more significant, particularly for high-surface-tension fluids such as water.
Why it matters for this archive
Supports the general principle behind Miniature thermosiphon scaling limits: below some tube-diameter threshold, passive circulation stops behaving like the clean, large-pipe thermosiphon flow the Double Play system relies on at building scale, and surface-tension/friction effects begin to dominate and destabilize flow.