DOI: 10.1615/TSFP7
PASSIVE SCALAR STIRRING BY MULTISCALE-GENERATED TURBULENCE
Краткое описание
The stirring and mixing of a passive scalar by fractal generated turbulence in the presence of a mean scalar gradient is studied in three dimensions by DNS (Direct Numerical Simulation). Passive scalar behaviour is of preliminary importance in turbulent mixing and can also provide an opportunity to understand turbulence itself. Recent experiments in wind tunnels [1, 2] have shown that it is possible to tune fractal objects (see figure 1) as very efficient turbulence generators of potential use for static inline mixers. In this numerical work, turbulent mixing in regular and fractal grid turbulence is investigated with a Prandtl number of 0.1. The results show that it is possible to improve turbulent stirring and heat transfer mixing by using a fractal square grid instead of a regular grid, even with the same blockage ratio and the same input velocity.