Application of non-intrusive conductance sensors to local measurement of two-phase flow

Void fraction is an important parameter in two-phase flow system, and an accurate measuring technique is essential. In order to avoid any distortion by an intrusive measurement, the non-intrusive conductance sensor was chosen in this study to measure the local signals in vertical rectangular tubes. The experimental conditions were fixed superficial water velocity (Jw) at 0.417m/s and various superficial air velocity(Ja) at 0.125~0.417m/s. NI-6255 was utilized as the data acquisition system. The results include 3-D mesh of all signals and the transient signal as well as the frequency of specific sensors. It was observed that the non-intrusive conductance sensor is an effective method to measure void fraction.