Multiphysics coupling of chaotic flow and electromagnetic heating in a mesoscale microwave reactor

Chaotic flow has significant advantages in enhancing laminar mixing and heat transfer in micro-nanofluidic systems, but the multiphysic process coupling chaotic flow with heat transfer enhancement technologies such as electromagnetic techniques in mesoscale systems accross such as chemistry, food science, and biology fields is still unclear. In this study, a mesoscale chaotic flow microwave heating system was designed to enhance the efficiency of mass and heat transfer. The mixing and heat transfer characteristics of C-type geometric chaotic flow at centimeter scale were systematically studied by numerical simulation and experimental verification. The characteristics of chaotic flow mixing and electromagnetic heat transfer were studied by considering the C-type geometric period parameters such as period spacing (L_d) and aspect ratio (W/H). The results show that, compared with the traditional microwave heating structure, the coupling of C-type geometric chaotic flow and electromagnetic heat significantly improves the mixing and heat transfer. When 20 mm ≤ L_d < 30 mm, the reactor performance can be maintained at a better level. The cross-section deformation caused by W/H has a key influence on fluid disturbance and temperature field distribution. In order to prevent the section height of the pipeline from being too high, and to reduce the mixing effect due to the spreading of the fluid after hitting the wall due to the inertial force, it is recommended that the value range of W/H be 1 ≤ W/H < 3. At the same time, in order to avoid high heat area after microwave heating for a certain time, W/H should be controlled at 2 ≤ W/H ≤ 5/2.This study lays a theoretical foundation for understanding the relationship between multi-physics process coupled chaotic flow and enhanced heat transfer technology in mesoscale systems.