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

Download
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.

Suggestions

Application of ultrasonic burning rate measurement method on closed bombs
Mumcu, Berkan; Kurtuluş, Dilek Funda; Arkun, Uğur; Department of Aerospace Engineering (2013)
In this thesis study, detailed information about solid rocket motors and ultrasonic burning rate measurement method is given. An experimental setup is prepared for applying the ultrasonic burning rate measurement method. Before performing the burning tests, some pre-tests are performed for affirming the ultrasonic sensor and obtaining some experimental coefficients. Two different types of propellants, which do not include aluminum, are produced for the burning tests. The first type of the propellants has tw...
Ballistic design optimization of three-dimensional grains using genetic algorithms
Yücel, Osman; Aksel, Mehmet Haluk; Department of Mechanical Engineering (2012)
Within the scope of this thesis study, an optimization tool for the ballistic design of three-dimensional grains in solid propellant rocket motors is developed. The modeling of grain geometry and burnback analysis is performed analytically by using basic geometries like cylinder, cone, sphere, ellipsoid, prism and torus. For the internal ballistic analysis, a quasi-steady zero-dimensional flow solver is used. Genetic algorithms have been studied and implemented to the design process as an optimization algor...
Service life assessment of solid rocket propellants considering random thermal and vibratory loads
Yılmaz, Okan; Özgen, Gökhan Osman; Kuran, Bayındır; Department of Mechanical Engineering (2012)
In this study, a detailed service life assessment procedure for solid propellant rockets under random environmental temperature and transportation loads is introduced. During storage and deployment of rocket motors, uncontrolled thermal environments and random vibratory loads due to transportation induce random stresses and strains in the propellant which provoke mechanical damage. In addition, structural capability degrades due to environmental conditions and induced stresses and strains as well as materia...
Analysis of grain burnback and international flow in solid propellant rocket motors in 3-dimensions
Yıldırım, Cengizhan; Aksel, Mehmet Haluk; Department of Mechanical Engineering (2007)
In this thesis, Initial Value Problem of Level-set Method is applied to solid propellant combustion to find the grain burnback. For the performance prediction of the rocket motor, 0-D, 1-D or 3-D flow models are used depending on the type of thre grain configuration.
Experimental and numerical investigation of an augmented spark igniter and evaluation of igniter’s effective flame length as a performance parameter
Öz, Levent Çağatay; Ulaş, Abdullah; Department of Mechanical Engineering (2019)
In the scope of this thesis, the impact of operating conditions on the performance of an augmented spark igniter in means of effective length of the flame developed by the igniter and thermal energy output of it, by using numerical and experimental techniques, is examined. The igniter uses gaseous oxygen as oxidizer and gaseous hydrogen as fuel. Tests were carried out for 3 different oxygen mass flow rate to fuel mass flow rate ratios, and at each ratio with four different total mass flow rates. Experimenta...
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.