NUMERICAL ANALYSIS OF THE INFLUENCE OF STIR ON WATER DURING MICROWAVE HEATING

In order to study the information of temperature with stir during microwave heating on water, the coupled Maxwell's equations, fluid field equations and heat transport equations were solved using Finite-Element Method (FEM). The microwave heating on water was analyzed with high power, different dynamic viscosities and relative complex permittivities. The results show that the highest temperature occurs on the interface of the water and air. When the water is heated under high microwave power, speeding up the stir can improve the uniform of temperature, but if the rotate speed is fast enough, going on speeding up the stir cannot decrease the temperature difference any more. When the value of the imaginary part of relative complex permittivity which accounts for dielectric losses or the dynamic viscosity increases, the temperature in the water rises very quickly, and the temperature difference is very large even if the rotate speed is fast enough.