1109 急拡大を伴う円管鉛直上昇気液二相流の流動様式

Abstract

Experimental studies were made on the multi-dimensional behavior of upward gas-liquid two-phase flow through the vertical round tube with an axisymmetric sudden expansion, which is one of the typical multi-dimensional channel geometry. The aims of this study are to clarify the multi-dimensional behavior of bubbly or slug flow affected by sudden expansion channel geometry, and to accumulate the experimental data for two-phase flow analysis, which is applicable to predict with appropriate accuracy the multi-dimensional its behavior. As the first step in this study, direct observation using high-speed video camera was performed and revealed the multi-dimensional dynamic flow behavior affected by the sudden expansion part. Characteristic phenomena were observed such as bubble break-up, deformation due to the strong share of liquid flow, or liquid micro jet penetration through the gas-slug, and so on. The void fraction profiles in sudden expansion were also measured using a pointed-electrode resistivity probe. From these results, the flow regime map at the below or above of the sudden expansion part were classified.