THEORY AND MEASUREMENT OF LOCAL INTERFACIAL AREA USING A 4 SENSOR PROBE IN 2-PHASE FLOW

A theoretical foundation of the measurement method for the time averag ed local interfacial area using a four sensor resistivity probe is pre sented. Based on this theory, the four sensor resistivity probe was de veloped and employed to measure the interfacial velocity, local interf acial 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 ca p bubbles. The theoretical predictions of the cap bubbles and the inte rfacial area concentration profiles compared very well with the four s ensor data.