Improvement on the two-phase-flow void fraction determination using Monte Carlo calculations

In this paper, a modified one-shot photon-attenuation method is presented for the determination of the average void fraction in a two-phase-flow system. The modification of the conventional one-shot method is established by a series of Monte Carlo Calculations. Through a benchmark test it is validated that the accuracies of the void-fraction prediction can be significantly improved. The application of this new technique is demonstrated using a mixed air-water flow channel. The results show that the improvement gained using this modified method is essential at low void fractions where the conventional one-shot method suffers high uncertainty. Another important correction made in this work is on the condition of the variation of void distribution with time. It is found that this correction can be significant when the void fractions in the flow channel are large. (author)