Application of ultrasonic technique for measurement of instantaneous burn rate of solid propellants

The ultrasonic pulse-echo technique has been applied for the measurement of instantaneous bum rate of aluminised composite solid propellants. The tests have been carried out on end-burning 30 mm thick propellant specimens at nearly constant pressure of about 1.9 MPa. Necessary software for post-test data processing and instantaneous burn rate computations have been developed. The burn rates measured by the ultrasonic technique have been compared with those obtained from ballistic evaluation motor tests on propellant from the same mix. An accuracy of about ± 1 per cent in instantaneous bum rate measurements and reproducibility of results have been demonstrated by applying ultrasonic technique.