Thesis (Ph. D.)--University of Washington, 1995. / Vita. Includes bibliographical references (leaves [76]-82).

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

Few experiments have been carried out in the past to deter mine the effect of the lift and the drag forces on the trajectory of a ball used in any game. In a baseball game, it was reported that sometimes the ball took a sharp turn aburptly in the region of 15 to 20 feet from the home plate. This indicated a sudden change of the forces acting on the ball. The principal forces acting w ere as fol lows: 1. Weight of the ball. 2. Drag force acting in the direction parallel to the relative wind. 3. Lift force acting perpendicular to the relative wind.

An overview of a flight simulation system is presented with a discussion of the system components and the interaction between functional units. The functions of each unit in the visual system are described. Specifically, the projectile subsystem portion of the visual system is presented in detail. A projectile subsystem executive structure is presented with capability of controlling projectile activation and deletion. Mathematical models for missiles with linear projected impact and proportional guidance are discussed. Ballistic projectile models with and without wind and drag considerations are developed. The mathematical equations for position and attitude calculations are given. Design considerations and implementation of algorithms are also presented with other system design trade-offs.

Comment quelques grammes de plomb propulsés par quelques grammes de poudre peuvent-ils avoir raison, à distance, du plus robuste des soudards ? Pourquoi le même projectile peut-il tuer l’un et épargner l’autre ? Depuis le XVe siècle, ces questions effraient le combattant, intriguent le chirurgien et agitent la communauté scientifique.Croisant données historiques, comptes rendus médico-légaux et expérimentation scientifique, cette étude tente de répondre à ces interrogations pluriséculaires. Les sources consultées reposent principalement sur les écrits chirurgicaux, mais explorent également les ouvrages traitant d’armes, de munitions et de tactique, partant du principe que tous ces facteurs jouent un rôle dans ce drame parfois définitif qu’est la rencontre tumultueuse entre un projectile et la cible particulière que constitue l’organisme humain. Les réponses apportées sont contrastées et souvent contradictoires : à ceux qui estiment qu’une plaie par projectile d’arme à feu est une plaie comme les autres répondent ceux qui considèrent que le mécanisme qui l’a produit doit être pris en compte dans l’étude de ces effets et dans la décision thérapeutique. Ce travail expose, au travers de ces polémiques, l’extrême diversité des effets vulnérants des armes à feu, aucun traumatisme balistique n’étant strictement superposable à un autre. Ce caractère non reproductible, en dehors de l’expérimentation scientifique, exclut toute conclusion formelle et définitive quant aux effets des projectiles d’armes à feu. Être touché par une balle reste une aventure individuelle aux conséquences imprévisibles. / How can a few grams of lead expelled with a few grams of powder remotely take out the toughest boor? Why can the same projectile kill one and spare the other? Since the 15th century, these questions frighten the fighter, intrigue the surgeon and stir the scientific community.Crossing historic data, medicolegal reports and scientific experiments, this study tries to answer these centuries-long questions. The consulted sources are mostly based on surgical writing but also explore books dealing with weapons, ammunition, tactics, given all these factors interneve in this, something definitive, drama that is the tumultuous encounter between a projectile and the particular target that the human body is. The results are mixed and often contradictory, opposing those who think a projectile-induced wound is a common wound and those who consider the igniting mechanism has to be taken into account to study and treat its effects efficiently. This work shows, apart from these polemics, the great diversity of firearms wounding effects, no ballistic trauma being strictly comparable to another. This non-reproductible specificity, aside from scientific experiments, rules out any formal and definitive answer regarding the effects of firearms projectiles. Being shot with a bullet remains an individual adventure with unpredictable consequences.

Currently, there are few analytical tools within the ballistics community to aid in the design and performance evaluation of aerodynamically asymmetric projectiles. The scope of this thesis is to (1) create analytical tools that are capable of quantifying aerodynamically asymmetric projectile performance, (2) demonstrate the ability of these models to accurately account for aerodynamic asymmetries, and (3) gain insight into the flight mechanics of several aerodynamically asymmetric projectiles. First, a six-degree-of-freedom (6 DOF) flight dynamic model, which uses a point-force lifting-surface aerodynamic model, was developed to replicate flight characteristics observed from measured results of common projectiles. A quasi-linear flight dynamic model was then created using the machinery of Projectile Linear Theory (PLT). From this, flight dynamic stability models were developed for linear time-invariant (LTI) and linear time-periodic (LTP) systems. Dynamic simulation and stability trade studies were then conducted on asymmetric variants of 4-finned, 3-finned, 2-finned, and hybrid projectile configurations. First, stability of symmetric projectiles are validated and show that the classical and extended PLT model yielded identical results. Results show that aerodynamic asymmetries can sometimes cause instabilities and other times cause significant increase in dynamic mode damping and increase/decrease in mode frequency. Partially asymmetric (single plane) configurations were shown to cause epicyclic instabilities as the asymmetries became severe, while fully asymmetric (two plane) can grow unstable in either the epicyclic modes or the roll/yaw mode. Another significant result showed that the LTP stability model is able to capture aerodynamic lifting-surface periodic affects to evaluate dynamic stability requirements for asymmetric projectiles.

No description available.

Currently, two methods exist to determine trajectory of a ballistic penetrator: Poncelet Analysis and Differential Area Force Law (DAFL) methods. An exact solution for the Poncelet Equation exists; making for easy computation. However, the one dimensional nature of the equation fails to capture the intricate three-dimensional nature of real world ballistic penetrator trajectories. The DAFL methods employ empirically derived stress algorithms to calculate to forces acting on a differential area of a projectile. These stresses are then used to determine the forces and moments acting on the differential areas. These forces and moments are then used to solve the equations of motion to determine the trajectory of the ballistic penetrator. The DAFL methods accurately capture the three dimensional nature of the penetrator's trajectory, but are computationally intensive which make them slow. The Integrated Force Law (IFL) method combines the computational ease of the Poncelet Analysis with the accuracy of the DAFL methods. In IFL, the projectile shape is modeled as a polynomial. The stress algorithms used in the DAFL methods are them numerically integrated over the top and bottom surfaces of the projectile to determine the force and moment acting on the top and bottom half of the weapon. These two forces and moments are then used to solve the equations of motion. J-hook trajectories are solved in less than 40 seconds and stable trajectories are solved in less than three seconds.

The effectiveness of a direct fire penetrator projectile equipped with an actively controlled ram air mechanism is investigated through dynamic simulation. The ram air control mechanism consists of a rotary sleeve valve which directs air flow from an inlet at the center of the nose to side ports. The projectile dynamics, the inertial measurement unit and the control system are included in the system model. It is shown that the ram air control mechanism provides sufficient control authority to significantly reduce dispersion of a direct fire penetrator. The effects of accelerometer and gyroscope bias and noise are investigated. It is seen that moderate values of bias and noise do not affect the dispersion significantly. But with higher values the dispersion is greater than the dispersion for the free flight. / Graduation date: 2002

This thesis is concerned with the energy loss of light atomic projectiles in thin boron films. In Chapter I, a brief theoretical description of the stopping process is given. In Chapter II, the experimental procedure is described and a method is given by which electronic stopping cross-sections can be determined from the observed energy loss. In Chapter III, the thin boron films that are used in the experiments are described in detail. In Chapter IV, the experimental results are presented, and in Chapter V the results are compared with existing data and theory. / Thesis / Master of Science (MS)