Integrated Modeling of Microwave Food Processing and Comparison with Experimental Measurements

This paper presents an integrated electromagnetic and thermal model for the microwave processing of food packages. The model is developed by combining the edge finite element formulation of the 3-D vector electromagnetic field in the frequency domain and the node finite element solution of the thermal conduction equation. Both mutual and one-way coupling solution algorithms are discussed. Mutual coupling entails the iterative solution of the electromagnetic field and the thermal field, because the physical properties are temperature-dependent. The one-way coupling is applicable when the properties are temperature independent or this dependence is weak. Mesh sensitivity and shape regularity for the edge element based formulation for computational electromagnetics are discussed in light of available analytical solutions for a simple wave guide. The integrated model has been used to study the electromagnetic and thermal phenomena in a pilot scale microwave applicator with and without the food package immersed in water. The calculated results are compared with the experimentally measured data for the thermal fields generated by the microwave heating occurring in a whey protein gel package, and reasonably good agreement between the two is obtained.

[1]  W Wiesbeck,et al.  Simulation of Microwave, Conventional and Hybrid Ovens Using a New Thermal Modeling Technique , 2000, The Journal of microwave power and electromagnetic energy : a publication of the International Microwave Power Institute.

[2]  R. I. Neophytou,et al.  COMPUTER SIMULATION OF A RADIO FREQUENCY INDUSTRIAL SYSTEM , 1996 .

[3]  D. C. Dibben,et al.  Frequency domain vs. time domain finite element methods for calculation of fields in multimode cavities , 1997 .

[4]  R. M. Perkin,et al.  The heat and mass transfer characteristics of boiling point drying using radio frequency and microwave electromagnetic fields , 1980 .

[5]  J. Volakis,et al.  Finite element method for electromagnetics : antennas, microwave circuits, and scattering applications , 1998 .

[6]  An Analysis of the Finite-Difference Time-Domain Method for Modeling the Microwave Heating of Dielectric Materials Within a Three-Dimensional Cavity System , 1996 .

[7]  Barry Joe,et al.  Quality local refinement of tetrahedral meshes based on 8-subtetrahedron subdivision , 1996, Math. Comput..

[8]  Juming Tang,et al.  Finite Difference Time Domain (FDTD) Characterization of a Single Mode Applicator , 2003 .

[9]  J. Pasciak,et al.  Computer solution of large sparse positive definite systems , 1982 .

[10]  C. Balanis.  Advanced Engineering Electromagnetics , 1989 .

[11]  Juming Tang,et al.  MOISTURE DISTRIBUTION IN SPHERICAL FOODS IN MICROWAVE DRYING , 1998 .

[12]  Ravindra Akarapu.  Finite element modeling of electromagnetic and thermo-mechanical phenomena in microwave and laser systems , 2003 .

[13]  A. C. Metaxas,et al.  Industrial Microwave Heating , 1988 .

[14]  A. Faghri,et al.  Experimental and Numerical Study of Microwave Thawing Heat Transfer for Food Materials , 1994 .

[15]  Carretera de Valencia,et al.  The finite element method in electromagnetics , 2000 .

[16]  Robert V. Decareau,et al.  Microwaves in the food processing industry , 1985 .

[17]  James Demmel,et al.  An Asynchronous Parallel Supernodal Algorithm for Sparse Gaussian Elimination , 1997, SIAM J. Matrix Anal. Appl..

[18]  S. Ohkawa,et al.  Analysis of Power Density Distribution in Microwave Ovens , 1978 .

[19]  A K Datta,et al.  Coupled Electromagnetic and Termal Modeling of Microwave Oven Heating of Foods , 2000, The Journal of microwave power and electromagnetic energy : a publication of the International Microwave Power Institute.

[20]  C. Seyler,et al.  Influence of the dielectric property on microwave oven heating patterns: application to food materials. , 1997, The Journal of microwave power and electromagnetic energy : a publication of the International Microwave Power Institute.

[21]  G. Mur.  Edge elements, their advantages and their disadvantages , 1994 .

[22]  P. Risman,et al.  Coupled electromagnetic and thermal modeling of microwave oven heating of foods. , 2000, The Journal of microwave power and electromagnetic energy : a publication of the International Microwave Power Institute.

[23]  B. Li,et al.  Three-dimensional Marangoni convection in electrostatically positioned droplets under microgravity , 2004 .

[24]  James Demmel,et al.  A Supernodal Approach to Sparse Partial Pivoting , 1999, SIAM J. Matrix Anal. Appl..