Study of internal-external burning solid rocket propellant

A rocket motor design has been carried out using internal-external combustion propulsion, using HTPB-based propellant with cylindrical grain. The thrust vs time curve obtained from the static test of this type of rocket motor shows a neutral profile and even tends to be regressive. The results of the performance of a rocket motor with a propellant length of 70 cm, produce an average thrust of 605 kgf, with a combustion time of 2.74 seconds (ISP: 195 seconds). The type of internal-external burning requires the strength of the rocket motor tube to the thermal load, in addition to the combustion pressure load. The composite rocket motor tube made of carbon fiber and fiber glass is able to withstand the thermal load and pressure of this internal-external burning rocket motor. The connection system between the tube and the nozzle, as well as the tube with the cap, uses a sock system instead of the screw or bolt system commonly used in metal rocket motor tubes.