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A Novel Methodology to Estimate Solid Propellant Temperature Before Ignition

The initial temperature of the solid propellant affects the burning rate of the propellant and performance of the solid rocket engine (SRE). This situation alters the range of the projectile. Thus, before ignition of a SRE the initial temperature of the propellant should be known in order to have accurate range calibrations. Developing a theoretical model to determine the temperature of the propellant would be ordeal. Numerical methods such as finite element (FE) method can be used, but it would be impractical in the field due to relatively long run times and necessity for a solver. In this study, a novel methodology is presented to estimate the temperature of the propellant within a very short time before the ignition. System identification method has been used to derive a mathematical model between the volume averaged temperature of the solid propellant, and ambient temperature and solar radiation. Ambient temperature and solar radiation, which depend on time and location, are the main factors influencing the temperature of the propellant, after the SRE has been taken out of a depot. The derived model has been validated by comparing the results with those obtained from the FE analyses.