保存性傾斜サーマルの流動特性 : 数値解析と画像解析

Abstract

The negative buoyancy of a conservative gravity current is kept into constant in the travel direction. On the other hand, negative buoyancy changes in the travel direction in a non-conservative gravity current. The saline thermal belongs to the conservative one. The particle gravity current belongs to the non-conservative one. The objectives of this study are to investigate the flow properties of the conservative inclined thermals by experiments, to obtain the velocity vectors using the image processor, and to compare the experimental results to the numerical ones of velocity fields. Also, the experimental results of the travel speed and the maximum thickness are compared with the numerical ones. The numerical model is based on the k-ε turbulence model and the SIMPLE model to discretize the partial differential equations. Those experimental results are explained by the numerical analysis. Three typical velocity vectors are found out, i.e. the roll up vectors in the front region, the strong vectors in the travel direction and the entrained vectors in the back region.departmental bulletin pape