Harmonic analysis of piston and pyrotechnic pulsers for T-burners

MALL samples of propellants are routinely tested in a Tburner apparatus to determine their tendency to burn unstably. For spontaneously unstable propellants, small acoustic disturbances in the T-burner can couple with the propellant combustion, leading to the growth of a pressure wave from which a propellant response function can be determined. Some propellants, especially those containing metal, are not spontaneously unstable, so that pulsed disturbances must be introduced into the burner chamber during burning and at burnout to excite the pressure waves. The decay rates of these waves can then be used to determine the propellant response