Investigation of the structure of multiscale-generated turbulence and scalar transport mechanism toward the development of high efficient mixer

本研究的目的是研究多尺度生成湍流的结构，这是由分形形状的网格，和标量（即，通过风洞实验和水槽实验以及三维直接数值模拟（DNSs）研究了分形湍流的能量产生和衰减机制，并通过测量湍流动能输运方程中的各项，研究了分形湍流的能量产生和衰减规律。DNS用于获得在实验中难以获得的统计数据。水槽实验结果表明，在分形产生的湍流中，标量输运明显增强。

The purpose of this study was to investigate the structure of multiscale-generated turbulence, which was generated by the fractal-shaped grids, and scalar (i.e., heat and mass) transport mechanism by means of laboratory experiments using wind tunnels and a water channel and three-dimensional direct numerical simulations (DNSs) using a supercomputer.The energy production and decay in the fractal-generated turbulence were investigated in the wind tunnel experiments by measuring all terms in the transport equation for turbulent kinetic energy. The DNS was used to obtain statistics which were hard to obtain in the experiments. The results of the water channel experiments showed that scalar transport is significantly enhanced in the fractal-generated turbulence.