Size Distribution of Particles in Combustion Products of Aluminized Composite Propellant

摘要

An experimental study is carried out to measure the size distribution of condensed particles in the combustionnproducts of aluminized composite propellant using quench bomb technique. One meter long and 200 mm diameternquench bomb with propellant specimens of mass u000132 is used. The effects of geometry of propellant specimen,nquench distance, and chamber pressure on the particle size distribution are investigated. Size distribution of thenparticles is measured by laser diffraction particle size analyzer and the surface structure is examined by scanningnelectron microscope. The study shows that the particles are spherical and their sizes vary from 0.1 to 300 u0001 . Thenparticles have trimodal distribution with modes at u00011 u0001 , u00014 u0001 , and u000170 u0001 . Although modes 1 and 4 u0001nparticles are alumina, mode 70 u0001 particles are aluminum agglomerates. About 30%of aluminum present in thenpropellant converts into agglomerates. Results also show that coalescence of particles is higher if the particles havenhigher residence time in the high-temperature region or when the flow is more turbulent. From the particle sizendistribution obtained in the quench bomb tests, the size distribution is deduced for the combustion chamber of rocketnmotor.