슬러그 유동 조건에서 국소 기포인자 측정을 위한 4-센서 광섬유 프로브 개발

Abstract

Bubble parameters such as void fraction, bubble velocity, and interfacial area concentration(IAC) are important for an accurate prediction of bubble behaviors in the two-phase flow. The 4-sensor probe method is one of the representative multi-sensor probe techniques which can measure the local bubble parameters regardless of bubble shape and bubble behavior. However, there is a lack of evaluation as to whether it is applicable to flow conditions in which distorted and slug bubbles appear. Therefore, in this study, the performance of 4-sensor probe was investigated with numerical simulations under the postulated flow conditions for various bubble shapes. It is found from the study that bubble parameters are measured more accurately as the radial distance between sensors is close. For the IAC, the method proposed by Revankar et al. showed the best accuracy. Also, in order to verify the design of the optimized 4-sensor optical fiber probe, verification experiment was performed in the air-water flow condition. It showed that the 4-sensor optical fiber probe(4S-OFP) measured the void fraction, bubble velocity, and IAC within 10 %, 8 %, and 22 % of deviations against visualization data, respectively.