Abstract
The effects of a turbulence-generating grid on fluid mixing and chemical reaction were experimentally investigated in a liquid sheared mixing layer. The grid was installed at various streamwise positions to find out the optimal position as a promoter for mixing and reaction. Instantaneous velocities and concentration were simultaneously measured by a laser-Doppler velocimeter and a laser-induced fluorescence technique, respectively. The results show that the grid generates disturbance at small scales and enhances fluid mixing. However, as the mixing proceeds, turbulence intensity becomes smaller than those in the flow without the grid. The latter negative effect remains almost entire region downstream of the grid whereas the former positive effect appears only in the near region of the grid. As a result, fluid mixing and chemical reaction are promoted most effectively when the grid is installed in the downstream region where the mixing layer has developed.
