一般化ランジュバンモデルによる円管内乱流中の壁面点源プルーム物質拡散場の数値シミュレーション : 物質注入源下流に面源を置いた場合 (<小特集>混相流の数値シミュレーションと新技術)

抄録

A generalized Langevin model described in the cylindrical coordinate system on the basis of the consistency condition up to the second-order moments of velocity has been applied to simulate the plume diffusion field of a high Schmidt number matter from a wall point source in a fully developed horizontal turbulent pipe flow. The plane source of the admixture particles with the number density distribution specified from the experimental data of the mean concentration is set up at some position downstream from the wall point source to avoid the disturbance caused by the injection of matter near the point source, since the present model assumes that the admixture particles have no influence on the fluid motion. From the simulation results, it is found that the simulated vertical and azimuthal profiles of the mean concentration at various downstream cross sections show good agreement with experimental data. The mean streamwise variations of the maximum mean concentration, and the half-widths of the vertical and azimuthal profiles of the mean concentration are also accurately predicted by the present model.