Burning rate and temperature measurements of HTPB/AP/A1 propellants at standard rocket motor tests

Resumo

© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.Three standard rocket motor tests (Lg/Dg ≈ 3.2 and 10 kg of propellant mass) casted with same HTPB/AP/Al solid propellant were conditioned at three different temperatures (20°C, 50°C and 72°C) in order to be fired at an horizontal bench test and investigate the influence of a thermal gradient appearance on the propellant grain by reducing its time of conditioning. The motors were instrumented with thermocouples placed over the case, nozzle and over the propellant spoke. The temperature levels were acquired prior and during the firing. Additionally, pressure and thrust profiles measured from the firings were plotted emphasizing the instant of membrane rupture and other important ballistic aspects. It was observed an important increasing on the Isp of the Motor Test #03 (72°C) and a thermal gradient induction of 2.9 °C, which led to slight variations on its pressure and thrust profiles with augmentation of progressive shape of the curves. Due to it, higher gradients must be investigated in new tests.