The viscosity and mechanical property of HTPB/AP composite solid propellant are profoundly affected by particle size of AP. In HTPB/AP propellant formulated by two mode of AP size such as 190 μm and 7 μm, the propellant was found to be much less viscose at end of mix when coarse/fine AP ratio is ranged from 70/30 to 60/40 due to high solid packing fraction. It was shown that the toughness of tensile strength test for HTPB/AP propellant increased with the increase in coarse AP.Considering both lower viscosity and better tensile strength, the optimum ratio of AP coarse/fine was estimated to be 70/30.
One of the plume characteristics of minimum smoke propellant is the infrared (IR) radiation signature, which may be useful for detection of rocket. The IR irradiance is known to be reduced by afterburning suppression in rocket plume by addition of potassium salt in propellant. The minimum smoke propellant with nitrate ester polyether (NEPE) binder system and nitramine oxidizers was researched for the afterburning and IR irradiance difference according to the content of potassium salt as afterburning suppressant in propellant formulation. The propellants were formulated to satisfy the level of AGARD smoke class AA and potassium sulfate was selected as afterburning inhibitor suitable for NEPE propellant. The afterburning flame length and mid‐range IR intensity were measured, while conducting static firing tests of 6 inch (15.24 cm) standard rocket motors loaded with minimum smoke propellants of the different contents of potassium sulfate. The total IR irradiance of HMX/RDX propellant with 1.1 % potassium sulfate was reduced to about 23 % compared to the propellant without afterburning suppressant due to the inhibition of afterburning. Also, the total IR irradiance of the HNIW (30 %)/RDX propellant was found to be almost three times more than that of the HMX/RDX propellant although the content of potassium sulfate was the same of 1.1 % in both propellants.
The infrared irradiance signature from exhaust plume is essential for the design of solid rocket motors. To overcome the difficulty of conducting experiments using real rocket motors, experimental studies were carried out to compare standard rocket motors and real rocket motors of the same propellant. The static firing tests on standard and real rocket motors of NEPE and HTPB propellants were conducted. Despite different rocket motor size and methodology of spectro‐radiometric measurement, the spectral characteristics of the infrared irradiance signature for both rocket motors were quite similar. The standard and real rocket motors of HTPB propellant showed similar tendency of steady infrared irradiance emission throughout the combustion, whereas both rocket motors of NEPE propellant showed a rapid emission in the midstream of combustion. The total infrared irradiance of NEPE was about 55 % less than that of HTPB propellant for both standard and real rocket motor experiments. Additionally, the relative amounts of chemical products produced during propellant combustion came out to be similar for both rocket motors. The experimental results indicated that the spectral characteristics of infrared irradiance and combustion products were quite similar for different sized rocket motors of same propellant and that a correlation of infrared irradiance signature exists between small‐sized standard rocket motors and real rocket motors. Thus, the spectral characteristics of real rocket motors could be reasonably estimated from the results of standard rocket motors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.