Author(s): MA Wencheng, LIU Lijun, School of Energy and Power Engineering, Xi’an Jiaotong University, Uonone Optoelectronics Technology Company Limited
Pages: 513-516
Year: 2016 Issue:  4
Journal: Journal of the Chinese Ceramic Society
Keyword:  sapphire; absorption coefficient; thermal stress; numerical simulation;
Abstract: For an industrial-scale sapphire furnace of heat exchanger method, a two-dimensional global model of heat transfer was established. The internal radiation heat transfer of crystal was simulated by discrete ordinate method. The effect of absorption coefficient on the temperature and thermal stress distributions in the sapphire crystal was investigated. The numerical results indicate that under the effect of the internal radiation, the region with great axial temperature gradient and thermal stress is located at the bottom of the crystal in a range of 1 cm from the bottom surface of the crystal. The maximal axial temperature gradient and stress firstly increase and then decrease with the increase of the crystal absorption coefficient from1.9 m^–1 to 1 900 m^–1.