Measurement Method of Void Fraction Using Needle Contact Probe with Fuzzy Set Rule

In an experiment on two-phase flow, it is often necessary to measure the void fraction distribution. The contact probe method is used because of its simple structure and low cost. This method is effective for determining local void properties, but ineffective for measuring void fraction distribution because the threshold of the probe signal voltage varies with the flow patterns. To overcome the difficulty in void distribution measurement, we applied the fuzzy set rule taking into consideration the properties of the probe. We propose a new probe measurement method of the void fraction using membership functions, and show that the method enables us to eliminate the dependence on flow patterns.