RESUMO
A method of obtaining time-resolved measurements of gas temperatures in a combustion environment is described. The noncontact optical laser-beam deflection technique utilizes rapid heating at a gas-solid interface as an acoustic source and is capable of acquiring localized temperature values at a repetition rate of >1 kHz. Measurements taken on a premixed propane-air laboratory flame show a 12.5-Hz thermal oscillation at the flame edge and no significant oscillation at the center.
RESUMO
A diagnostic system for measuring the beam power and quality of a high-power cw CO(2) electro-aerodynamic laser is described. A ZnSe beamsplitter was employed to split off a small fraction (0.5%) of the main laser beam for diagnostic purposes. The low-power beam was split again to provide two beams for power and energy-distribution measurements, concurrent with sample irradiation by the main beam. An electrically calibrated disk calorimeter was used to measure beam power. The temporal and spatial energy distributions were measured by means of a mechanically scanned, one-dimensional pyroelectric array. This provided a 16x16 element two-dimensional map of the beam profile at a rate of up to 10 Hz.
