Measurement of Void Fraction in a Two-Phase Flow for Unstable Liquid Conductivity in Multi-Electrode Voltage–Current System Using a Normalization Equation With Two Correction Parameters

Abstract

The normalization equation with two correction parameters ${\beta }$ and ${\gamma }$ is proposed to estimate the void fraction of liquid–gas flow under the condition of unstable liquid conductivity using a multi-electrode voltage–current (me-VC) system. The variation of electrical current value due to change in liquid conductivity of liquid phase is corrected using parameter ${\beta }$ . While ${\gamma }$ is the gradient correction parameter, which corrects the different variation rate of normalized electrical current affected by liquid conductivity and the void fraction ${\alpha }$ in liquid–gas flow. A lookup table for ${\beta }$ and ${\gamma }$ is created based on the normalized electrical current obtained at four liquid conductivity and six void fraction conditions. From the experimental results, the proposed normalization equation with ${\beta }$ and ${\gamma }$ shows better performance in estimating void fraction than conventional normalization equation when the conductivity of liquid in liquid–gas flow is unstable. Through the results, it is found that the proposed normalization equation successfully measures the void fraction ${\alpha }$ within a 5% error rate.