孔隙分布对陶瓷材料热辐射特性的影响
Influences of pores distribution on thermal radiation properties of ceramic materials
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摘要: 通过引入吸收性介质内粒子散射Mie理论,结合多弥散粒子系独立散射理论,针对孔隙具有修正Gamma分布规律的多孔陶瓷提出一种计算热辐射特性的方法,以氧化锆陶瓷为例分析了孔隙分布对热辐射特性的影响.结果表明孔隙分布规律和平均孔径对热辐射特性有显著影响.孔径趋于单弥散分布,将使衰减系数、散射反照率、非对称因子等参数减小,而孔径趋于指数分布,这些参数显著提高.当波长较小时,衰减系数随平均孔径先增大后减小,当波长较大时,衰减系数随平均孔径增大而减小;散射反照率和非对称因子均随平均孔径增大而增大.Abstract: A rigid Mie solution on scattering by a spherical particle immersed in an absorbing medium was introduced. By combining with independent scattering discipline for polydisperse particles, a theoretical method was presented for calculating thermal radiation properties of ceramics with pores in modified Gamma distribution. Influences of pores distribution and mean diameter on thermal radiation properties of a specific Yt stablized zirconium (YSZ) were analyzed. Results show that pores distribution and mean diameter have significant influences on thermal radiation properties of the ceramic. Extinction coefficient, scattering albedo and asymmetry factor decreases with pores distribution approaching mono dispersion and increases with pores distribution approaching poly dispersion. An optimal mean diameter of pores exists for extinction coefficient in short wavelength while the coefficient decreases with pores mean diameter in long wavelength. Both scattering albedo and asymmetry factor increase with pores mean diameter.
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