Abstract:Microwave plasma has a wide range of applications in the fields of material processing,energy and environment,but the factors that affect the electric field enhancement effect of microwave irradiation on spherical char particles are not yet clear.By establishing the electromagnetic wave-solid heat transfer coupling model,the electric field strengthening effect between two spherical char particles is studied.The results show that when the angle between the surface normal at the contact point of the two particles and the direction of the electric field increases from 40° to 50°,the incident angle of the microwave reaches the critical incident angle of the char interface,and the electric field strengthening effect reduces abruptly.The penetration depth of microwave in spherical char particles plays a decisive role in the electric field strengthening effect; the best condition for electric field strengthening effect between spherical char particles is small spacing rather than no spacing.