1. While flaws in the simulated RR #2 dataset hamper definitive discrimination among timepoint definitions and among burning rate procedures, some general trends are suggested. The RR #2 results did not recover the reference-burning rate that was inputto theSPPsimulation. The burning rates and burning rate coefficients were overpredicted, while the exponent was slightly under-predicted, but within 1%. All analysis methods yielded an average deviation of 0.5% relative to the baseline for the cases of high L* data, the influence of ignition, and erosive burning. However, a deviation in burning rate for the TOT methods of 4 - 18% relative to the baseline rate for the nozzle erosion and off-axis bore cases. The deviation for theTOT methods with respect to the reference rate Is even larger. The deviation in burning rate for the MB methods remained at less than 1% for all the cases examined. The MB methods seem to provide better agreement when compared with either the baseline or the reference burning rate, exponents orcoefficients.
2. International RR#3 Results RR #3 is based on a computer program, created by R. Messier and R. Glick in support of the WG 016, to generate simulated motor data for research into burning rate measurement methods.3RR #3 consists of ten different pressure-time traces for 5 baseline and 5 off-axis bore cases. Ten pressure-time histories comprising two groups simulate generic 2x4-inch motor behavior. Each group contains five motors, equally spaced in log pressure. RR #3 responses were received in early-1999 from the following 18 volunteer participants: DREV, SNPE, Bayem Chemie, POLIMI, TNO-PML, Royal Ordnance, Alliant Tech Systems, AMCOM, ARC, BF Goodrich, NAWCWD, NSWC, P&W/CSD, SNAP/Jordan, Stone Engineering, Thiokol, and Messier. Nine of the participants, Canada, the European facilities, Thiokol, and R. Messier used TOT methods to reduce the data and determine the propellant burning rates, while the remaining nine participants from the U.S. used MB methods. Lessons on RR #3 and #3Xare summarized below.
3. International RR#3X Results RR #3X is also based on the Hessler-Glick ballistic simulation of a 2x4-inch motor configuration. RR #3X consists of 40 additional cases, arranged in eight groups of simulated rocket motors beyond those examined in RR#3. These additional groups are mainly perturbations of the original RR #3 Group 2, which had constant bore offset. These groups are designed to examine the effects of nonneutrality, L-star, further bore offset perturbations, and of higher rate, pressure, and exponent. Data typically unknown, such as the burning rate equation, bore offset, and randomized parameters were withheld from the participants. RR#3X responses were received in late-1999 from POLIMI, who analyzed the cases using TOT methods from BayemChemie,and Messier.