Measuring Technique Research On High Temperature Particle Infrared Radiation Characteristic

Many materials in the fields of chemical, metallurgical, power, construction, medicine, biology, food, aerospace, military and atmospheric sciences, and other fields, are in state of particle. Typical particle medium include: the flame of contain carbon black and fly ash, reactant in catalytic reactor, jet stream and the plume of a solid propellant rocket. The plume of a solid propellant rocket engine is full of high temperature particles which include Al₂O₃,MgO,ZrO₂and emission gases which include H₂O,CO₂,CO. Inorder to research the spectral properties of the plume of a solid rocket, we must master spectral property of high temperature particle.The optical constant (complex refractive index) of the material is a basic physical property that is related to the composition, temperature and surface condition. Since the surface of the particle material is much bigger than that of the bulk material, moreover, since the high temperature particles are easy to accumulate into a mass, Thus the surface of the high temperature particle is very complicated and the complex refractive index of particle is big different from that of bulk material. The complex refrative index of particles can not directly measure through experiment (not have directly measure instrument), must survey other quantity from experiment, then combination corresponding theoretical model to inverse, it belongs to the conversion problem research. But now, our country has not developed high temperature complex refractive index of particle. This program is from nation natural science fund major project (serial number:50336010), is a part of item of multiple-dimensioned and multiparameter analyze in infrared radiation characteristic and radiation transfer. It's purpose is to develop high temperature particle spectral radiation property measurement equipment, carries out online measurement on high temperature particle, realizes the theoretical and experimental research on high temperature particle optical property, offers different temperature optical property measurement data base.Based on the specific aspect of set up high temperature particle spectral radiation property measurement equipment and the particle spectral radiation property measurement under different temperature, combining the development of the spectral radiation property measurement instrument, the thesis elaborates the radation transfer theory deeply, optical property measurement method, light scattering theory, module parameter optimizing and the evaluation method of the measure uncertainty. The finished research works are as follows:1. Set up high temperature particle spectral radiation property measurement equipment, debug and well measurement equipment. Domestically, first to take off experiment of high temperature spectral complex refractive index, which can consider both particle and piece form material measurement. It realized multiform particle levitation and heat up; realized the quasi-stationary particle space distributing field of different temperature and density; established experiment foundation for particle radiation.2. Research on inversion model which use the precise Mie theory and the Kramers-Kronig relation and transmittance to solve complex refractive index of monodispersion particl. We establish inversion model of complex refractive index of high temperature particl, analyse monodrome and multiple valued of inversion model, analyse influence of measurement error to inversion model.3. In order to contrast result of complex refractive index of particle, better detect density andt average diameter of particl in experiment, based on the Mie theory and the Lambert-Beer transmittance law, we use genetic algorithms to inverse particle distribution. Under Matlab environment, we emulate and verify some crucial parameters of particle radiation property, prove the method is reasonable.4. To resolve the problems that the traditional algorithm of particle size distribution inversion has no good convergence accuracy and is apt to be trapped in local optima, a stochastic particle swarm optimizer(SPSO) algorithm, which is based on laser transmitting model, is proposed to estimate the size distribution of particles.The novel SPSO-based method is proved to be available to retrieve the reasonable particle size distribution such as R-R distribution, normal distribution and lognormal distribution for the independent model.5. Base on introduction using of FT-IR spectrometer and define of response function of FT-IR spectrometer, we proceed the preform transmission experiment and dispersion transmission experiment of Al₂O₃particles, we inverse the complex refractive index of Al₂O₃ particles under different temperature and analyse the uncertainty of experiment system.The studied contents of the thesis establish a strong technical and theoretical foundation for the complex refractive index of particle database under different temperature.