Numerical Analysis of Heat Transfer Characteristics in Microwave Heating of Magnetic Dielectrics

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 43; no. 3; pp. 1070 - 1078
• Main Authors: Peng, Zhiwei, Hwang, Jiann-Yang, Park, Chong-Lyuck, Kim, Byoung-Gon, Onyedika, Gerald
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.03.2012; Springer; Springer Nature B.V
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Dielectrics; Exact sciences and technology; Heat transfer; Heating; Magnetism; Materials Science; Mathematical models; Metallic Materials; Metals. Metallurgy; Microwave heating; Microwaves; Minerals; Nanotechnology; Nonuniform; Numerical analysis; Physical metallurgy; Structural Materials; Surfaces and Interfaces; Temperature profiles; Thin Films; Microwave; Magnetite; Microwave Heating; Microwave Processing; Heating Time; Microwave heating; Dielectric materials; Heat transfer
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-011-1014-3

A numerical simulation of heat transfer during the microwave heating process of magnetite, which is a two-dimensional (2-D) magnetic dielectric, subjected to heat conduction, convection, and radiation was performed. The heat transfer process was modeled using an explicit finite-difference approach, and the temperature profiles for different heating parameters were generated through developing a code in Mathematica 7.0 (Wolfram Research, Inc., Champaign, IL). The temperature in the sample increases rapidly in 1 minute and nonuniform temperature distribution inside the object is observed. An obvious temperature hot spot is formed in the corner of the predicted temperature profile initially, which shifts to the center of the object as heating power increases. Microwave heating at 915 MHz exhibits better heating uniformity than 2450 MHz mainly because of the larger microwave penetration depth. It is also observed that the heating homogeneity in the object can be improved by reducing the dimension of object. The effects of heating time, microwave power, microwave frequency, and object dimension need to be considered to obtain high heating performance and avoid/minimize thermal runaway resulting from temperature nonuniformity in large-scale microwave heating.