| This study deals with the dynamic behavior of a spinning body of the rocket-type. The general goal is to increase scientific understanding of the behavior of variable mass systems, and to augment the existing arsenal of mathematical tools and relationships that can be used in the design of rocket type systems.; There are two practical objectives delineated for this work. One is to re-examine some of the simplifying assumptions that have been traditionally used in the study of variable mass systems, by quantifying their impact on motion predictions, and also determining whether these assumptions are in fact reasonable. The second objective is to extend the work of previous investigators in this field by utilizing a more realistic model for the rocket than have been used in the past, and to explore propellant burn patterns that go beyond those studied by previous investigators.; One of the two major assumptions that are relaxed is the one that ignores the contributions of the fluid products of combustion within the combustion chamber of a rocket to the mass and inertia of the rocket. The second assumption that is re-examined has to do with the manner in which fluid particles move within a rocket's combustion chamber. It has been traditional to assume that the velocity of any fluid particle within a rocket's combustion chamber relative to the rocket body is parallel to the rocket's axis, and that all the fluid particles have the same velocity. Yet, engineering intuition tells us that a transverse component for fluid velocity is inevitable in the case of a spinning rocket. In this study, the validity of this assumption is assessed.; The attitude behavior of rocket systems is known to be influenced by the manner in which mass loss affects the geometry of the system. In addition to the radial burn, this document presents in-depth studies of three other propellant burn patterns: the uniform burn, the end burn, and the centripetal burn. |
