Investigations of aluminum behavior and its role using laminate propellants

J. C. Mullen, M. Q. Brewster

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In AP composite propellants, the composition and structure of the fuel-rich matrix ("pocket") between coarse AP particles affect combustion behavior. Laminates of ammonium perchlorate/hydroxyl-terminated polybutadiene (AP/HTPB) propellants intermixed with powdered aluminum, nominally 15 um, at 15% and 31% loading, by mass, are used to study the behavior of aluminum in AP composite propellants where the AP is characterized by two disparate length scales, fine (2 μm) and coarse (hundreds of μm). The AP laminate takes the place or plays the role of the coarse AP particles but simplifies the system by creating a nearly 2-D, steady outer (canopy) flame structure. Aluminized oxidizer/hydrocarbon mass ratios of 60/40 and 76/24 are tested in two configurations: matrix and laminate (a matrix layer between coarse AP slabs). A high speed camera images experiments at pressures from 3 atm to 30 atm. In matrix only formulations, the higher oxidizer containing propellants exhibit a transition from burn to no-burn as pressure increases whereas when the oxidizer/fuel ratio is reduced, the oxidizer/hydrocarbon matrix burns leaving behind unburned, unagglomerated aluminum. Laminate investigations indicate a non-protruding fuel layer for 76/24 formulations whereas protrusion occurs in 60/40 formulations. An increase in aluminum agglomerate diameter is observed in 60/40 laminates as compared with 76/24 laminate formulations. Burn rate data for varying pressures and fuel layer thicknesses is also examined.

Original languageEnglish (US)
Title of host publicationCollection of Technical Papers - 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference
Pages6317-6326
Number of pages10
StatePublished - Dec 10 2007
Event43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference - Cincinnati, OH, United States
Duration: Jul 8 2007Jul 11 2007

Publication series

NameCollection of Technical Papers - 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference
Volume7

Other

Other43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference
CountryUnited States
CityCincinnati, OH
Period7/8/077/11/07

ASJC Scopus subject areas

  • Space and Planetary Science

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  • Cite this

    Mullen, J. C., & Brewster, M. Q. (2007). Investigations of aluminum behavior and its role using laminate propellants. In Collection of Technical Papers - 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference (pp. 6317-6326). (Collection of Technical Papers - 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference; Vol. 7).