Modification and experimental validation of a combined optical and collection probe for solid propellant exhaust analysis

Abstract

A combined optical and collection particle sizing probe was further developed and utilized for in situ measurements in the exhaust plumes of solid propellant rocket motors. Probe shock-swallowing capabilities were verified using Schlieren observations under restricted motor operating conditions. Particle size number distributions obtained optically using a Malvern Mastersizer and from an automated data retrieval system for scanning electron microscope photographs of collected particles were in good agreement when referenced to common measurement limits. Most of the particles were smaller than 0.5 u but a significant number were present with diameters 19 10 u. A very few particles large than 15 u were also present, some as single particles and some as agglomerates. SEM results showed that many particles were smaller than 0.2 u outside the range of the Malvern instrument. Suggestions are made for further improvements and validation procedures for the probe.