Analysis of microwave heating of materials with temperature‐dependent properties

Role of metallic and composite (ceramic–metallic) supports on microwave heating of porous dielectrics

“…The interface conditions for energy balance and electric field equations due to multiple phases are automatically satisfied via an interface element common to two phases. At the interface node, the field variable and fluxes are continuous as discussed by Reddy [27] and Ayappa et al [1]. To discretize the time domain, Crank-Nicholson method is used, and the nonlinear residual equations are solved using Newton Raphson Method [7,8].…”

“…In contrast, during microwave heating, the material dielectric loss which is a function of frequency of microwaves, is responsible for the conversion of electric energy to heat. A significant amount of theoretical studies has been carried out by earlier researchers of microwaves [1][2][3][4] to understand spatial power and temperature distributions within samples. Ayappa et al [1,2] carried out detailed theoretical analyses for microwave heating of 1D slabs and 2D cylinders.…”

“…A significant amount of theoretical studies has been carried out by earlier researchers of microwaves [1][2][3][4] to understand spatial power and temperature distributions within samples. Ayappa et al [1,2] carried out detailed theoretical analyses for microwave heating of 1D slabs and 2D cylinders. Transient temperature profiles were predicted within multilayered slabs and cylinders of dielectric materials by simultaneously solving Maxwell's equation and heat equation.…”

Shape Effect on the Temperature Field during Microwave Heating Process

“…Electromagnetic field distribution of the microwave treatment process can be described by Maxwell's equations or Lambert's law [13]. The propagation and absorption of microwave electromagnetic field can be described by Maxwell's equations and the accuracy of Lambert's law which is based on an assumption of semi-infinite critical sample length [17], which is verified when the thickness of the sample is more than three times the microwave penetration depth of the sample [18]. Taking the scope of application and accuracy into account, Maxwell's equations are the best choice to describe the electromagnetic field distribution.…”

“…Researches on foodstuff microwave treatment processes are mostly concentrated on two aspects: one aspect is the dielectric properties of the object itself, including factors affecting dielectric properties [18,21], shape effect [22][23][24], and deformation effect [25]. Researches on aspects other than the target object like microwave equipment structure [26,27], microwave properties [28], microwave processing strategies [20,29], and experimental verifications [30,31] are also being performed at the same time.…”