Burning Rate of Solid Propellant Ingredients, Part 2: Determination of Burning Rate Temperature Sensitivity

Abstract

aep D [± rb=±T0]p Care must be taken in how one evaluates aep when making comparisons of various materials. The collection of burning rate data, number of points measured at a given condition, initial test conditions, and inherent data scatter will have an effect on the value obtained for the burning rate temperature sensitivity. ‡‡;§§ The largestvariationsinburning ratemeasurementsgenerally occur at low pressures, where one approaches the dee agration limit of thematerial,andatregionswhereabreakintheburningratepressure exponentoccurs.Coincidentally,theseareoftentheareasofgreatest interest when determining the burning rate temperature sensitivity. The changes in aep that occur due to data smoothing vs averaging, and with the selection of the initial pressure and temperature conditions, can be signie cant. The effect of initial temperature selection on aep will be demonstrated using the HMX data, and e tting techniques will be illustrated with the ADN data, where considerable data scatter is present. Samples Thedee agrationdataforthesixmonopropellantslisted inTable1 of Ref. 2 will be used to demonstrate the evaluation of burning rate temperature sensitivity. The tabular burning rate data may be found in Refs. 3 and 4. The sample type and preparation was described in Ref.4.Alloftheburningratemeasurementsusedinthispaperforthe calculations were made using the cinephotomicroscopy technique also described in Refs. 3, 4, and elsewhere.