Quench cooling under reduced gravity

TL;DR

This study investigates how gravity levels affect quench cooling of liquid oxygen, revealing microgravity prolongs cooling time due to gas isolation, and subcooling significantly enhances heat transfer.

Contribution

It demonstrates the impact of reduced gravity on quench cooling dynamics and analyzes the effects of subcooling on heat transfer in liquid oxygen.

Findings

Microgravity extends cooling time due to gas isolation.

Subcooling reduces cooling time by about 20 times.

Experiments are unsuitable for analyzing critical heat flux (CHF).

Abstract

We report the quench cooling experiments performed with liquid O2 under different levels of gravity simulated with the magnetic gravity compensation. A copper disk is quenched from 270K to 90K. It is found that the cooling time in microgravity is very long in comparison with any other gravity level. This phenomenon is explained by the isolation effect of the gas surrounding the disk. The liquid subcooling is shown to drastically improuve the heat exchange thus reducing the cooling time (about 20 times). The effect of subcooling on the heat transfer is analyzed at different gravity levels. It is shown that such type of experiments cannot be used for the analysis of the critical heat flux (CHF) of the boiling crisis. The minimum heat flux (MHF) of boiling is analyzed instead.