Ultrasonic measurement of solid propellant burning rates in closed bombs and subscale motors

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2016
Atak, Özen
In the scope of this thesis, applications of ultrasonic measurement method on closed bombs and test motors were investigated with various aluminized and nonaluminized propellants with the main target of evaluation of burning rates. Detailed comparison between conventional methods for solid propellant burning rate measurements such as strand burner, firing of subscale test motors and ultrasonic measurement was performed. Burning rate evaluation of eight propellant batches were determined by thirty three closed bomb tests. For qualification of the ultrasonic measurement method, twelve tests that belong to HSTYPE5 propellant batch were investigated. The results showed good agreement with the results of firing of subscale test motors. Monte Carlo simulation was used for performing the uncertainty analysis related to closed bomb tests. Uncertainty for the closed bomb test set up used in Roketsan is between %2 and %10. Regarding to the test motor studies, a test motor was designed and manufactured for the purposes of the applications of ultrasonic measurement. Three successful tests were carried out with three different types of propellants. After qualification of the measurement method on closed bombs, studies of test motors were performed. The results obtained from the test motors were compared with the results of firing of subscale test motors for the same propellant composition. The results were comparable with each other. Moreover a numerical analysis was conducted in order to determine thermal profile at motor case that belongs to subscale test motor 3. At first, a test case was chosen from the open literature and various turbulent models were considered to predict the pressure and velocity profiles related to experimental study. The results showed that K omega SST turbulence model was suitable for thermal analysis of subscale test motor. During the firing of subscale test motor, thermocouples were employed on motor case with the main target of measuring temperatures at stated locations. Results of the numerical study were compared with the results of the experimental study.
Citation Formats
Ö. Atak, “Ultrasonic measurement of solid propellant burning rates in closed bombs and subscale motors,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.