TY - JOUR
T1 - Emission imaging of AP/HTPB propellant sandwich combustion
AU - Chorpening, B. T.
AU - Brewster, M. Q.
N1 - Funding Information:
Ultraviolet emission imaging (305−315 nm) was used to study the combustion of sandwiches of ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) in nitrogen at pressures up to 32 atm, with binder layers from 50 to 450 mm in thickness. The emission imaging was combined with a novel backlighting technique to allow determination of the corresponding surface shape during combustion. The results indicated that the interface regression rate of IPDI-cured samples undergoing laser-assisted deflagration (120 W=cm2 average flux) is nearly independent of the binder thickness for binders thicker than 100 mm. The pressure exponent of the regression rate is 0.31 up to 15 atm, then increases with pressure from 15 to 32 atm. Two primary flame regimes were identified: a regime of high Peclet and Damköhler numbers which exhibits a split base in the ultraviolet flame emission, and a regime of low Peclet and Damköhler numbers which exhibits a merged flame base. A third, ``lifted'' flame region, in which the strongest flame emission starts several hundred microns above the solid surface, occurs with low Damköhler numbers and high Peclet numbers. The effects of Pe and binder oxygenation (by fine-AP) on the size of the diffusion flame and the Received 2 March 2001; accepted 8 November 2001. This article is not subject to U.S. copyright laws. The support of this research by the Office of Naval Research and the Ballistic Missile Defense Organization (contract number N00014-95-1-1339) is gratefully acknowledged. *Address correspondence [email protected]
PY - 2002/4
Y1 - 2002/4
N2 - Ultraviolet emission imaging (305-315 nm) was used to study the combustion of sandwiches of ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) in nitrogen at pressures up to 32 atm, with binder layers from 50 to 450 μm in thickness. The emission imaging was combined with a novel backlighting technique to allow determination of the corresponding surface shape during combustion. The results indicated that the interface regression rate of IPDI-cured samples undergoing laser-assisted deflagration (120 W/cm2 average flux) is nearly independent of the binder thickness for binders thicker than 100 μm. The pressure exponent of the regression rate is 0.31 up to 15 atm, then increases with pressure from 15 to 32 atm. Two primary flame regimes were identified: a regime of high Peclet and Damköhler numbers which exhibits a split base in the ultraviolet flame emission, and a regime of low Peclet and Damköhler numbers which exhibits a merged flame base. A third, "lifted" flame region, in which the strongest flame emission starts several hundred microns above the solid surface, occurs with low Damköhler numbers and high Peclet numbers. The effects of Pe and binder oxygenation (by fine-AP) on the size of the diffusion flame and the location of its leading edges relative to the AP/binder interface were observed to be in agreement with Shvab-Zeldovich theory.
AB - Ultraviolet emission imaging (305-315 nm) was used to study the combustion of sandwiches of ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) in nitrogen at pressures up to 32 atm, with binder layers from 50 to 450 μm in thickness. The emission imaging was combined with a novel backlighting technique to allow determination of the corresponding surface shape during combustion. The results indicated that the interface regression rate of IPDI-cured samples undergoing laser-assisted deflagration (120 W/cm2 average flux) is nearly independent of the binder thickness for binders thicker than 100 μm. The pressure exponent of the regression rate is 0.31 up to 15 atm, then increases with pressure from 15 to 32 atm. Two primary flame regimes were identified: a regime of high Peclet and Damköhler numbers which exhibits a split base in the ultraviolet flame emission, and a regime of low Peclet and Damköhler numbers which exhibits a merged flame base. A third, "lifted" flame region, in which the strongest flame emission starts several hundred microns above the solid surface, occurs with low Damköhler numbers and high Peclet numbers. The effects of Pe and binder oxygenation (by fine-AP) on the size of the diffusion flame and the location of its leading edges relative to the AP/binder interface were observed to be in agreement with Shvab-Zeldovich theory.
KW - Laminar diffusion flames
KW - Solid propellant rockets
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U2 - 10.1080/713713012
DO - 10.1080/713713012
M3 - Article
AN - SCOPUS:0347079584
SN - 0010-2202
VL - 174
SP - 39
EP - 60
JO - Combustion science and technology
JF - Combustion science and technology
IS - 4
ER -