Response of PDPA to optical materials and thickness of test section window

Abstract

The objective of this work is to study the response of phase calibrated Phase Doppler Particle Analyser (PDPA) in presence of various arrangement schemes of optical materials and thickness of the test section window. The standard “Mono sized droplet generator” (MDG) has been used as a source of mono sized droplets stream. Receiving optics collection angle, Bandpass filter, and Photo-multiplier tube (PMT) voltage has been optimized using a known mono-size droplet stream. The results indicate that maximum perturbation in response occurs in presence of 17.5 mm Plexiglas thickness. The reduction in 97% of data rate is noted in Scheme B, whereas no data has been observed for the case of Scheme D. The maximum data rate reduction of 15.9% is observed in 17.5 mm Plexiglas of Scheme D for aligned PDPA subsystem. The results of the experiment also reveal that when unpolished glass is used instead of Plexiglas, the maximum date rate reduction is 70% for 17.5 mm for Scheme D whereas when subsystems are aligned then maximum loss of data rate is 11.3%, which are significantly higher to losses due to Plexiglas.