Burning rate measurement of solid propellant using ultrasound - Approach and initial experiments

To measure the burning rate of a solid propellant as a function of pressure using ultrasound, in the present study, a burning camber and an ultrasonic measurement system are specially designed and fabricated. In addition, data acquisition and analysis programs are also developed to determine the burning rate vs. pressure curve from the measured ultrasonic signals and pressures during the tests. Using the developed system, the wave speeds of the propellant are measured in the pre-test and the interface and burning surface echoes are acquired during the burning test together with the pressure inside the bomb. Based on these measurements, the burning rates of two kinds of propellants are successfully determined and compared to those measured by a strand burner method for the verification of the developed system and the proposed data analysis approach. For a propellant with high burning rate, the result obtained by the ultrasonic measurement shows a very good agreement to that measured by the strand burner method. Unfortunately, however, for a propellant with slow burning rate the result shows fairly large discrepancy in the initial experiments carried out in the present study.