Cs. Eberle et al., OPTIMIZATION OF A ONE-SHOT GAMMA-DENSITOMETER FOR MEASURING AREA-AVERAGED VOID FRACTIONS OF GAS-LIQUID FLOWS IN NARROW PIPELINES, Measurement science & technology, 5(9), 1994, pp. 1146-1158
A novel theoretical method for optimization of a gamma densitometer wa
s applied in measuring the area-averaged void fraction in gas-liquid f
lows. This theory provides design criteria that are comprehensive, mec
hanistic, quantitative and all are obtained from first principles. Als
o, a computer simulation was developed to test the design criteria and
the predictions were compared with experimental data in the literatur
e. Extensive experimental validation of the optimization theory was pe
rformed. Direct in situ measurement of void fraction using differentia
l pressure, a double-sensor resistivity probe and lucite mock-ups were
compared with the optimized gamma densitometer measurements. The resu
lts demonstrated good agreement between the reference measurements and
the gamma densitometer in each case. The measured void fractions for
the concurrent vertical forced flow ranged from 0.02 to 0.8, and spann
ed the bubbly, slug and churn turbulent flow regimes in a 25.4 mm tube
. The mock-up studies used lucite tubes of 12.7 mm outer diameter as s
ubstitutes for the flow field over void fractions ranging from 0.03 to
0.8.