Radiation Spectral Analysis and Particle Temperature/Velocity Measurement in Plasma Spray with One-Color Camera

摘要

A color camera optical diagnostic imaging system has been developed for the measurement of temperature and velocity of individual in-flight particles in thermal plasma spray, based on the principle of particle streak velocimetry and two-color thermometry. Radiation spectral analysis of the characteristic behavior of a particle-laden plasma plume was performed to identify an optimal spectral range for accurate temperature measurements over which the powder particles and the interfering thermal plasma gas are discernable. Calibration of the thermal imaging system was carried out using a blackbody furnace with uncertainties less than 1.8%. Extensive experimental measurements were taken with the optical imaging system to obtain the temperature and velocity distributions of YSZ particles in practical plasma spraying applications. The uncertainties of the measured temperature and velocity with a color camera system mostly fluctuate around +/- 10% in comparison with data obtained from a commercially available measuring system.