Experimental validation of a combined electromagnetic and thermal FDTD model of a microwave heating process

Ma, Lizhuang; Paul, DL; Pothecary, Nick; Railton, CJ; Bows, John R.; Barratt, L.; Mullin, John A.; Simons, D. H.

doi:10.1109/22.473179

Cited by 131 publications

(8 citation statements)

References 9 publications

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“…However, the respective model was not validated for the process chamber investigated. Other models of microwave-assisted processes were validated with analytical results in an empty cavity [29], temperatures measured with fiberoptic sensors [21,49], or spatial distributions of heating patterns [50,51]. These methods do not necessarily indicate an accurate representation of the electromagnetic field in the entire frequency range of 2.4 GHz to 2.5 GHz.…”

Section: Model Validationmentioning

confidence: 99%

Microwave-Assisted Freeze-Drying with Frequency-Based Control Concepts via Solid-State Generators: A Simulative and Experimental Study

et al. 2023

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Freeze-drying is a common process to extend the shelf life of food and bioactive substances. Its main drawback is the long drying time and associated high production costs. Microwaves can be applied to significantly shorten the process. This study investigates the effects of modulating the electromagnetic field in microwave-assisted freeze-drying (MFD). Control concepts based on microwave frequency are evaluated using electromagnetic simulations. The concepts are then applied to the first part of primary drying in a laboratory-scale system with solid-state generators. Targeted frequency modulation in the electromagnetic simulations enabled an increase in energy efficiency or heating homogeneity throughout MFD while having negligible effects on the power dissipation ratio between frozen and dried product areas. The simulations predicted the qualitative effects observed in the experimental proof of concept regarding energy efficiency and drying homogeneity. Additionally, shortened drying times were observed in the experiments with a targeted application of energy-efficient frequencies. However, differences occurred in the quantitative validation of the electromagnetic models for energy efficiency in dependence on frequency. Nevertheless, the models can be used for a time-efficient investigation of the qualitative effects of the control concepts. Therefore, frequency-based control of MFD represents a promising approach for process control and intensification.

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Section: Model Validationmentioning

confidence: 99%

Microwave-Assisted Freeze-Drying with Frequency-Based Control Concepts via Solid-State Generators: A Simulative and Experimental Study

et al. 2023

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“…Most previous works predicted the distributions of electromagnetic fields inside cavities and waveguides from the solution of Maxwell's equations; but, other studies assumed a source term with exponential decay (Lambert's law) [14][15][16][17]. The finite difference time domain (FDTD) method has been widely used to solve Maxwell's equations [18][19][20][21]. Of many previous studies on modeling of microwave heat transfer, most were concentrated on single-layer materials.…”

Section: Introductionmentioning

confidence: 99%

Numerical Model of Microwave Driven Convection in Multilayer Porous Packed Bed Using a Rectangular Waveguide

Klinbun

Rattanadecho

2012

Journal of Heat Transfer

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The present work studies numerically the heating of multilayer porous packed bed which is subjected to the microwave radiation with a rectangular waveguide. The multilayer porous packed bed consists of the layers of fine and coarse beds. The simulations of electromagnetic field are described by solving Maxwell’s equations with the finite difference time domain (FDTD) method. The flow fields and the temperature profiles are determined by the solutions of the Brinkman–Forchheimer extended Darcy model, energy, and Maxwell’s equations. The study aims to understand of the influences of layered configuration, layered thickness, and operating frequency on the transport processes in a multilayer porous packed bed. The results show that all parameters have significant effect on the distributions of electromagnetic field inside a waveguide, temperature profiles, and velocity fields within the multilayer porous packed bed.

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“…The temperature increase induced in the biological sample by the absorbed e.m. power was numerically evaluated by means of the heat transfer equation [14,22]:…”

Section: Thermal Simulations Of the Exposed Biological Samplementioning

confidence: 99%

“…More insights are given into the e.m. and thermal simulations of the dosimetric setup performed by homemade computer codes based on the Transmission Line Matrix (TLM) method and on the Finite Difference Time Domain (FDTD) algorithm, respectively [19][20][21][22]. Furthermore, the simulation results are compared with those obtained by temperature measurements.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic and Thermal Analyses of Improved Gtem Cells for Bioelectromagnetic Experiments

Calò¹,

Petruzzelli²

2012

PIER

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Abstract-A GHz Transverse Electromagnetic (GTEM) cell is proposed to investigate the arising of biological effects due to electromagnetic signals at the typical frequencies of mobile phone communications.The proposed GTEM cell, placed within a commercial incubator, has been ad hoc designed and fabricated to expose in vitro samples. The electromagnetic and the thermal analyses of the GTEM cell are reported. In particular, the inner electromagnetic field and the Specific Absorption Rate of the exposed sample (saline solution having 9 g/l concentration) have been evaluated by a homemade computer code based on the transmission line matrix method. Furthermore, the thermal analysis of the exposure arrangement has been carried out by the finite difference time domain algorithm.

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Experimental validation of a combined electromagnetic and thermal FDTD model of a microwave heating process

Cited by 131 publications

References 9 publications

Microwave-Assisted Freeze-Drying with Frequency-Based Control Concepts via Solid-State Generators: A Simulative and Experimental Study

Microwave-Assisted Freeze-Drying with Frequency-Based Control Concepts via Solid-State Generators: A Simulative and Experimental Study

Numerical Model of Microwave Driven Convection in Multilayer Porous Packed Bed Using a Rectangular Waveguide

Electromagnetic and Thermal Analyses of Improved Gtem Cells for Bioelectromagnetic Experiments

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