KURENAI : Kyoto University Research Information Repository

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The value of K in Eq.(6) was determined by least squares fitting, using
the present experimental data over a subcooling range of 0 to 70 K.
The result is given by
where c = 0 (AT sub - 0 - 40 K)
K = 0.03648 ( LO )-°•2° (Pv)-0.79 +.6 , (8-1)
dheAL
= 0.00808 (pV09 -i
~H.- LH.
)-1•a0(ATsub=
L pHisub
40 - 70 K) (8-2) A
In this experiment, dh e ranged from 1805 to 963 mm for heater diameter
from 0.8 to 1.5 mm.
On the other hand, gmax ,0 in Eq.(6) is given by Eq.(9), by using
least squares fitting
g
GHx'0=0.3740
fgALD (p°)06p.66(GZ)°•4°-(9)
By substituting Eqs.(8) and (9) into Eq.(6), we have
gmaxPv
= 0.3740 ()O.66()0.40
GHf gPLG LO
x [ 1 + {0.03648
1'0 Pv
()-0.20()°•79+e}.x1](10)
hePLfg
_AH .
where e is given by Eq.(8-2) and is a small contribution'. (15.% at most).
A comparison of Eq.(10) with the present steady state maximum heat flux
6 data is made in Fig
.11inGHaxvs. (PV)o•66(G_Z)0.4o(1+KH) diagram.
fgZ0fg
The data,scatter around Eq.(10) within ±10 % error bands.
Borishansky et al. [23] reported steady state maximum heat flux under
forced convection in an annular passage whose geometry is similar to that in our
experiment. In their experiment, a 3 mm o.d., 7.2 cm long heater is located
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