Study On The Measurement Method Of Spectral Radiative Properties Of Semitransparent Solid Materials At High Temperature

In recent years, in the aerospace, new energy, chemical and other fields, the heat transfer process involves the semitransparent materials, Radiation heat transfer of semitransparent materials, especially radiation heat transfer of semitransparent materials at high temperature is very important to improve equipment performance. The radiative transfer calculations must know the radiation characteristic parameters of the semitransparent materials In this paper, the measurement method of spectral radiative properties of semitransparent solid materials at high temperature were studied.First of all, Under high temperature, through the analysis of materials internal radiative transfer process, The normal emissivity is established relationship with the absorption and scattering coefficient. Considering material internal scattering effects, Combining with the scattering coefficient of the material at normal temperature and emissivity at high temperature, the material absorption coefficient is obtained. the measurement methods is established to obtain the material absorption coefficient and scattering coefficient at normal temperature.based on the integrating sphere measurement experiment, it gets the material absorption and scattering coefficient combining inversion method.Secondly, Established the spectral emissivity measurement of semitransparent solid material:moving the sample and the bottom of the double-base method. Emissivity measurement principle is established Measuring the characteristics of the object itself, It is adopted Christiansen wavelength thermometry and contact temperature measurement, and verify the feasibility of Christiansen wavelengthOnce again, high-temperature semitransparent materials emissivity measurement system is developed. Electric heating device is designed, The numerical simulation verified this device heating uniformity of samples and sample temperature can meet the experimental requirements, And this device is used to measure the emissivity of SIC opaque samples, its value has a good agreement with literature values. At the same time, based on the mobile samples and the bottom of the double-base method, the normal emissivity measurement of high purity alumina materials is tested at 100 ℃～700 ℃ by electric heating device and A540 devices. The experimental results were analyzed in comparison.the relative uncertainty analysis of the measuring system is presented.Finally, in the case of ignoring material internal scattering effects and considering the effects of scattering, Based on experimental measurement of material under high temperature and absorption and scattering coefficient under room temperature which gained by inverting. It Indirectly obtained the absorption coefficient of materials under high temperature.