流木群の流動に関する研究(3)一流木の回転運動を考慮した解析一

Abstract

A numerical simulation model has been developed for computing the behavior of driftwood and its dam up process due to jamming between and/or in front of the houses when driftwood debouches into horizontally two-dimensional flow field.Calculations were made with an interacting combination of Eulerian fluid and Lagragian driftwood equations.Equation of rotational motion of driftwood is evaluated dynamically as well as equation of translational motion.The positions, rotational angles of grouped pieces of driftwood, and the amount of dam-up of water level due to jamming of driftwood found experimentally are well explained by the calculated values.Moreover, the risk of swept away of wooden houses found to be increased by the dam-up experimentally.