Numerical simulation of thermal runaway in alumina during microwave processing
- SCRAM Technology, Inc., Gainesville, FL (United States)
A numerical method is used to simulate heating of processed samples with microwave energy in a closed cavity. Explicit finite difference schemes for solving the unsteady equations governing electromagnetic propagation (Maxwell`s equations) and energy deposition and diffusion are coupled. Simulations are performed for processing of alumina at 2.45 GHz in a multi-mode cavity. Steady state temperature profiles are achieved if the electrical properties are assumed constant, but when more realistic temperature dependent property data are employed, local heating produces an exponential rise in temperature (thermal runaway). It is shown that by enlarging the sample for a respective cavity, thermal runaway can be avoided. The authors emphasize that understanding the parameters that influence electromagnetic intensity distributions and promote resonance is a prerequisite for developing processing methods to control sample temperature.
- OSTI ID:
- 435669
- Report Number(s):
- CONF-951135-; ISBN 0-7918-1751-2; TRN: IM9710%%327
- Resource Relation:
- Conference: 1995 International mechanical engineering congress and exhibition, San Francisco, CA (United States), 12-17 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the ASME Heat Transfer Division. Volume 2: Fire and combustion systems; Thermal-hydraulics in nuclear and hazardous waste processing and disposal; Transport phenomena in materials processing; HTD-Volume 317-2; Atreya, A. [ed.] [Univ. of Michigan, Ann Arbor, MI (United States)]; Gritzo, L. [ed.] [Sandia National Labs., Albuquerque, NM (United States)]; Saltiel, C. [ed.] [SCRAM Technology, Inc., Gainesville, FL (United States)] [and others]; PB: 592 p.
- Country of Publication:
- United States
- Language:
- English
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