Ranges of heat transfer coefficients attainable for different coolants

1.

2.

Ranges of heat transfer coefficients attainable for different coolants
with natural convection, single-phase liquid forced convection, and
boiling
2

3.

1756
Johann Gottlob Leidenfrost
The Leidenfrost effect
3

4.

1934
1952
c p T
hLG
0.013(
q
hLG
g ( L V )
)1/3 (
cp
)1.7
The Rohsenow pool-boiling correlation
1965
Pool boiling curve (Nukiyama)
1950
qкр 0.16hLG V 4 g ( L V )
The dependence of Kutateladze for CHF
Schemes of vapor structures (Gaertner)
4

5.

1977
Successive stages of growth of two bubbles at
boiling of nitrogen in the film
2013
The dynamics of the «crater» formation
1989
Photographs of the structures observed in a
thin oil layer: (1) intersection of filaments in the
area of convection cells where funnels are
formed (the funnels are shown by arrows); (2)
simultaneous formation of two funnels in the
same place, 1 - cm scale; (3) funnels on the
surface of horizontal layer of mineral vacuum
oil spaced from each other at a distance of
about critical wavelength of Rayleigh–Taylor
instability, 1 - cm scale; (4) crater in the oil
layer, marked by a cross, 1 - cm scale
5

6.

2016
«Funnels» + «craters»
Map of hydrodynamic regimes of evaporation and boiling
of the n-dodecane layer height h = 2,5 mm:
1 – bubbles, 2 – «craters», 3 – «funnels», 4 – «funnels»
+ «craters», 5 – convection, 6 – the Dependence of
Kutateladze, 7 – calculation by Yagov formula, 8 –
calculation by Landau formula
The crisis of evaporation
6

7.

2006
side view
2009
front view
2018
Pool boiling curve with PF5060 of enhanced structured,
adapted from Im et. al. (2012)
7