TY - JOUR
T1 - Reduced agglomeration of aluminum in wide-distribution composite propellants
AU - Mullen, Jessica C.
AU - Brewster, M. Q.
N1 - Funding Information:
Support for this work from the U.S. Department of Energy (UIUC-ASCI Center for Simulation of Advanced Rockets) through the University of California (subcontract number B341494) and the Hermia G. Soo Professorship are gratefully acknowledged. Many thanks to Russell Fitzgerald for his contributions in the area of nonaluminized, oxygenated laminate propellants.
PY - 2011
Y1 - 2011
N2 - Aluminum behavior (accumulation, agglomeration and ignition) is studied in a unique, wide-distribution, ammonium perchlorate/hydroxyl-terminated polybutadiene propellant formulation that results in low Al agglomeration, even at low pressures (1-30 atm).Afuel-rich, physically oxygenated binder matrix highly loaded with very fine ammonium perchlorate at a high fine ammonium perchlorate/binder ratio is found to have premixed flame conditions that produce minimal agglomeration (without ignition) of Al. Coarse ammonium perchlorate is added to the system in the form of either particles or pressed-ammonium perchlorate laminates (simulated coarse ammonium perchlorate). Both laminate and particulate systems show that with coarse ammonium perchlorate present, Al can agglomerate on coarse ammonium perchlorate via lateral surface migration from fuel matrix to the coarse ammonium perchlorate region. The particulate coarse ammonium perchlorate system also shows that Al can accumulate/agglomerate via settling on coarse ammonium perchlorate from above (in the direction of burning). Both systems show that with coarse ammonium perchlorate present, Al is ignited by the outer coarse ammonium perchlorate/fuel matrix canopy flames, which the laminates clearly show to be either split-diffusion or mergedpartially- premixed, depending on pressure and diffusion length scale (fuel layer thickness). Thus a propellant formulation is proposed for reducing overall Al agglomeration through intrinsically reduced agglomeration in the fuel matrix and a reduced number of coarse ammonium perchlorate-particle agglomerates via higher fine ammonium perchlorate/coarse ammonium perchlorate ratio.
AB - Aluminum behavior (accumulation, agglomeration and ignition) is studied in a unique, wide-distribution, ammonium perchlorate/hydroxyl-terminated polybutadiene propellant formulation that results in low Al agglomeration, even at low pressures (1-30 atm).Afuel-rich, physically oxygenated binder matrix highly loaded with very fine ammonium perchlorate at a high fine ammonium perchlorate/binder ratio is found to have premixed flame conditions that produce minimal agglomeration (without ignition) of Al. Coarse ammonium perchlorate is added to the system in the form of either particles or pressed-ammonium perchlorate laminates (simulated coarse ammonium perchlorate). Both laminate and particulate systems show that with coarse ammonium perchlorate present, Al can agglomerate on coarse ammonium perchlorate via lateral surface migration from fuel matrix to the coarse ammonium perchlorate region. The particulate coarse ammonium perchlorate system also shows that Al can accumulate/agglomerate via settling on coarse ammonium perchlorate from above (in the direction of burning). Both systems show that with coarse ammonium perchlorate present, Al is ignited by the outer coarse ammonium perchlorate/fuel matrix canopy flames, which the laminates clearly show to be either split-diffusion or mergedpartially- premixed, depending on pressure and diffusion length scale (fuel layer thickness). Thus a propellant formulation is proposed for reducing overall Al agglomeration through intrinsically reduced agglomeration in the fuel matrix and a reduced number of coarse ammonium perchlorate-particle agglomerates via higher fine ammonium perchlorate/coarse ammonium perchlorate ratio.
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U2 - 10.2514/1.50127
DO - 10.2514/1.50127
M3 - Article
AN - SCOPUS:79955947804
VL - 27
SP - 650
EP - 661
JO - Journal of Propulsion and Power
JF - Journal of Propulsion and Power
SN - 0748-4658
IS - 3
ER -