A Study of Heat Transfer in Vertical Two Phase Flow - Concern with void fraction -

수직관내 이상류(二相流)에 있어서 열전달(熱傳達)에 관한 연구 (보이드율을 중심으로)

This study was to predict subcooled void fraction in water under low velocity ($0.03{\sim}0.5m/s$) and low pressure. ($1.53Kg/cm^2$ a) The experiments were done to determine void fraction in a uniformly heated annular test section. Some models from the literature were compared to the experimental results, but none gave consistently good predictions. A method using an empirical factor was developed to predict the void fraction. This model was applied to the test results and found to be good for some ranges of flow velocities.