Theory and measurement of local interfacial area using a four sensor probe in two-phase flow

Abstract A theoretical foundation of the measurement method for the time averaged local interfacial area using a four sensor resistivity probe is presented. Based on this theory, the four sensor resistivity probe was developed and employed to measure the interfacial velocity, local interfacial area concentration and void fraction in a vertical air-water cap bubbly flow. The four sensor probe measurements were checked against the global void measurement using a differential pressure. The results were very satisfactory. Theoretical profiles of the void fraction and interfacial area concentration were obtained using the pictures of cap bubbles. The theoretical predictions of the cap bubbles and the interfacial area concentration profiles compared very well with the four sensor data.