Study on Gas-Liquid TwoーPhase Flow Using Image Processing and Neutron Radiography Technique

利用中子射线照相技术对以下三种金属通道内的气液两相流动进行了可视化实验：(1)窄矩形通道内（1x40mm）气液两相流动，(2)小直径管内（内径4mm）气液两相流动，(3)小直径管内（内径5mm）沸腾两相流动。金属通道的这类实验不能用x射线照相，只能用中子照相。利用在线中子电视观测了流体的流态和空洞行为，并绘制了流态图，与传统的流态图吻合较好。通过图像处理技术测量了平均孔隙率。为了获得金属通道内两相流动的清晰图像，使用了日本原子能研究所的JRR-3和NSRR。综上所述，图像处理与中子成像技术的结合实现了对窄通道、小直径管内两相流的定量研究。

The experiments on visualization of gas-liquid two-phase flow in the following three metal channels were performed using neutron radiography technique :(1) gas-liquid two-phase flow in a narrow rectangular channel (1x40mm),(2) gas-liquid two-phase flow in a small diameter tube (inner diameter, 4mm),(3) boiling two-phase flow in a small diameter tube (inner diameter, 5mm).This kind of experiments in metal channels can not be done by using X-ray radiography but neutron radiography.With an on-line a neutron television, flow pattern and void behavior were observed, and a flow pattern map was made, which agrees well with the conventional ones. Average void fraction was also measured through an image processing technique.In order to obtain clear images of two-phase flow in metal channels, the JRR-3 and NSRR in the Japan Atomic Energy Research Institute were utilized.In conclusion, we can say that the combination of image processing and neutron radiography techniques realize the quantitative study on two-phase flow in narrow channels and small diameter tubes.