Tk. Thiyagarajan et al., VOID FRACTION PROFILE MEASUREMENTS IN 2-PHASE MERCURY-NITROGEN FLOWS USING GAMMA-RAY ATTENUATION METHOD, Experimental thermal and fluid science, 10(3), 1995, pp. 347-354
A nonintrusive measurement system using gamma rays from a Co-60 source
is developed to measure the void fraction profile in a two-phase flow
of a high-density liquid metal and nitrogen. The method is based on t
he attenuation of gamma rays along various chord lengths in the cross
section of a pipe line. Both the chord segment inversion (CSI) method
and the feast squares solution (LSS) method were applied to obtain voi
d fraction profiles from the data. The CSI method gave spurious oscill
ations in the void fraction profiles, which could be attributed to the
Poisson corruption due to low count rate. On the other hand, the LSS
method did not contain any oscillations. Experiments were performed in
the vertical riser pipe of a gravitational-type liquid metal magnetoh
ydrodynamic loop with mercury-nitrogen two-phase flow. Void fraction p
rofiles were obtained for various flow rates at two locations in the r
iser pipe. The average void fraction obtained from the profile data wa
s compared with the values predicted by empirical relations developed
for vertical two-phase hows.