Effects of beam steering on the accuracy of long-path optical diagnostics of plumes
A preliminary simulation of the beam trajectory inside a synthetic turbulent plume was completed to investigate the potential range of beam deflections at a stand-off distance of 60 m corresponding to recent sky-LOSA field measurement conditions. Finely resolved temperature data extracted at a downstream plane of a simulated heated turbulent jet were used in the analysis and scaled by Reynolds number to simulate a generic turbulent flare plume. The results of the simulation showed that the distortion caused by beam steering should be within 0.25 mm (95% confidence interval) over a stand-off distance of 60 m. Compared with the typical projected spatial resolution in the plume of 8.4 mm for recent sky-LOSA measurements, this suggests the beam steering effects are likely negligible in typical sky-LOSA measurement applications. In addition, analysis of the fluctuations of illumination intensity showed that the beam steering results in fluctuation of less than 1%. Since these fluctuations are averaged during data processing, they should be negligible during sky-LOSA measurements.
|Conference||108th Air and Waste Management Association Annual Conference and Exhibition - Connecting the Dots: Environmental Quality to Climate, ACE 2015|
Sawires, D. (David), Johnson, M.R, Hendra, G.R. (Graham R.), & Bushe, W.K. (W. Kendal). (2015). Effects of beam steering on the accuracy of long-path optical diagnostics of plumes. In Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA (pp. 355–361).