Measurement of Solid Propellant Burning Rates During Rapid Depressurization

摘要

A microwave continuous measurement technique has been used to measure burning rates of a carboxyl-terminated polybutadiene and ammonium perchlorate composite solid propellant during rapid decompression. A microwave signal oscillating at a known source frequency is passed through the end of a burning propellant strand opposite the burning surface and allowed to reflect off the burning surface. By continuously comparing the phase angle of this reflected signal with the phase angle of another signal oscillating at the orginal source frequency, a relative phase angle of another signal oscillating at the original source frequency, a relative phase angle between the two signals is obtained. The rate of change of this relative phase angle with time is proportional to the propellant's burning rate. Possible errors were investigated and conclusions reached concerning them. (Author)