RT Journal Article ID 45bb4c0f25e6b8eb A1 Risha, Grant A1 Harting, George C. A1 Peretz, Arie A1 Koch, Donald E. A1 Jones, H. Stephen A1 Arves, Joseph P. T1 SURFACE HEAT RELEASE OF HTPB-BASED FUELS IN OXYGEN RICH ENVIRONMENTS JF International Journal of Energetic Materials and Chemical Propulsion JO IJEMCP YR 2002 FD 2002-01-01 VO 5 IS 1-6 SP 101 OP 115 K1 combustion K1 activation energy K1 surface heat release K1 solid fuel K1 decomposition K1 JIRAD K1 HTPB AB An experimental study was conducted to determine the dependence of the regression rate of two solid-fuel formulations (cured HTPB and JIRAD fuel) on operating conditions near the head-end of a hybrid motor. Cylindrical fuel samples were burned in a windowed combustor at pressures ranging from 0.79 to 3.55 MPa. The burning was sustained by a diffusion flame created over the fuel surface by an impinging oxidizer jet. The gaseous oxidizer, delivered at an initial temperature between 220 to 298 K, was a mixture of oxygen and nitrogen, with the oxygen mass fraction ranging from 0.21 to 1.00. For both fuels, the regression rate increased with oxidizer mass flow rate, oxygen mass fraction, and oxidizer temperature, but decreased at higher pressures in the range tested. Measured regression rates, surface temperatures, and operating parameters were used to validate a simple power-law regression rate correlation for each fuel. The heats of decomposition of these solid fuels were determined from a fast thermolysis study using a gas chromatograph/mass spectrometer equipped with a pyrolyzer. The pyrolysis activation energy of HTPB was lower than that of JIRAD fuel. Therefore, HTPB is more reactive. Additionally, the amount of surface heat release was found to decrease with increasing solid fuel regression rate for both fuels, which suggests that higher blowing rates reduce the amount of oxygen available for reaction at the surface. The surface heat release for each fuel was correlated using a power law expression. PB Begell House LK https://www.dl.begellhouse.com/journals/17bbb47e377ce023,76f8e14974df93a8,45bb4c0f25e6b8eb.html