Numerical Simulation of Concentration Gradient Generator Based on Cantor Fractal Principle

This paper mainly studies the design of a concentration gradient generator. Since the fractal principle has been shown to have unique geometric properties, we study the fractal principle together with the concentration gradient generator. We designed an obstacle based on the Cantor structure fractal applied the obstacle to the concentration gradient generator and then used the simulation software COMSOL Multiphysics 5.2a based on the finite element theory to carry out the numerical simulation. (a) The effect of fractal obstacle series on the concentration gradient, (b) the effect of microchannel height on the concentration gradient, and (c) the effect of different inlet velocities on the concentration gradient. A series of conclusions are obtained. The primary and secondary fractal obstacle has little influence on the concentration gradient. With the increase in the height of the microchannel, the change in the concentration gradient is small. The concentration gradient curve at different flow rates of the three-inlet concentration gradient generator shows a normal distribution trend. When the velocity decreases from 5×10^-3 m/s to 1×10^-5 m/s, the peak value of the curve decreases from 0.6 mol/L to about 0.35 mol/L. The concentration gradient curves at different flow rates of the two-inlet concentration gradient generator show a linear trend. When the velocity decreases from large 5×10^-3 m/s to 1×10^-5 m/s, the vertex value of the curve decreases from 1 to about 0.5 mol/L of complete mixing.