A detailed experimental study was carried out to compare basic aerodynamic characteristics of a generic axisymmetric projectile configuration (cone cylinder model) obtained at the FSU polysonic wind tunnel with a large-scale test facility and predictive methods of varying fidelity. In order to generate an aerodynamic database and study the control effectiveness of AFRL boost configuration and investigate the effect of protrusions on the aerodynamic characteristics measurements were carried out over a range of test conditions. The aerodynamic characteristics of an axisymmetric tangent ogive body with and without fins at supersonic speeds were compared to the existing wind tunnel data and predictive methods. Measurements conducted at the Florida State University Polysonic Wind Tunnel (PWST) were compared to the retired Defence Evaluation Research Agency (DERA) wind tunnel database and numerical simulations performed using Cobalt and Cart3D flow solvers and Missile Datcom at DSTL-UK. The results show a good agreement among the test facilities. Three prediction methods, Cart3D, Cobalt and Missile Datcom, were also compared to the large-scale facility and FSU data for a baseline cone cylinder. It was determined that the Cobalt predictive results agreed best with the data from both wind tunnels, the Cart3D had a generally good agreement, besides the angle of attack range of 5° < α < 10° where the inviscid solver didn’t account for the crossflow vortices and other viscous effects. Missile Datcom also had good agreement overall but was seen to overpredict the coefficient of normal force at high angle of attacks. The trends for each predictive method were seen to stay the same for the most part for the deflected fin cases, with Missile Datcom having slight improvements. It was also determined that for the Reynolds number range of 0.6 million to 1.2 million at Mach 3 the axial force was seen to be affected for the baseline cone cylinder. The baseline cone cylinder with fins was also tested in this Reynolds number range and it was seen that the Reynolds number had a negligible effect on the coefficient of normal force, side force, axial force and center of pressure. A detailed experimental study was also carried out to develop an aerodynamic database for a Tangent Ogive Axisymmetric Body with Fins (Boost Model) and determine the maximum pitch and roll effectiveness for this. Measurements were carried out over a range of Mach numbers from 0.5 to 4, Reynolds number based on body diameter of 1.9 million, and fin deflection angles of 0°, ±5º, ±10º, ±15º, ±20º and ±30º. The maximum control angle was found for a subsonic (Mach 0.5), transonic (Mach 1.1) and supersonic (Mach 3) condition. It was seen that as the Mach number increased the effective control surface angle also increased, and the fins effectiveness in terms of producing pitch moment and roll moment is linear with fin deflection. The Boost Model was also tested with the addition of two protrusions added to the underside of the model to understand the effects which they will have on the basic aerodynamics. The twin pipes were seen to increase the coefficient of drag at supersonic speeds and have little to no effect at subsonic speeds. Additionally, the twin pipes were seen to have no effect on the coefficient of normal force at subsonic and supersonic speeds. At high angles of attack, the asymmetry cause by the twin pipes increased the drag coefficient as the model was rolled. Flow visualization using high-speed shadowgraphy and surface oil flow were carried out to study flow features on around the twin pipes and fins. / A Thesis submitted to the Department of Mechanical Engineering in partial fulfillment of the requirements for the degree of Master of Science. / 2019 / November 13, 2019. / Aerodynamic Characteristics, Fin Effectiveness, Ogive, Polysonic, Shadowgraph / Includes bibliographical references. / Rajan Kumar, Professor Directing Thesis; Carl Moore, Committee Member; Chiang Shih, Committee Member.

This thesis examined the hypothesis that radiative heat transfer in small-scale printed-fuel hybrid rocket motors is responsible for the observed decreasing oxidizer-to-fuel (O/F) ratio shift. The magnitude of the radiation term was negligible for the motor sizes and types of propellants that have been previously tested, but was reintroduced in this study. To prove this hypothesis, a detailed enthalpy balance model was developed and tested using experimental fuel regression rate data obtained from a variety of motor scales using additively-manufactured acrylonitrile butadiene styrene (ABS) fuel grains.

abstract: Planetary Defense is the scientific field of study dedicated to the detection and mitigation of a potential threat posed to Earth by a Near Earth Object (NEO), whether an asteroid or a comet. It is a fairly recent scientific field of study. The first Planetary Defense offices were created in the United States in 2017 and at the European Space Agency (ESA) in 2019. Should an impact occur, the Planetary Defense community, an international network of Planetary scientists, is set to work in coordination with international and national emergency response services to deal with such a natural celestial disaster. This dissertation will revolve around the hypothesis that over the past twenty-five years Planetary Defense has morphed from a scientific field dedicated to asteroid detection to a broad managerial international technocratic infrastructure. Considering that such a disaster could have consequences of potentially globally catastrophic proportions, including possibilities for large-scale tsunamis, firestorms, and stratospheric darkening, it is critical that any NEO disaster management and coordination efforts be informed by proven theoretical principles and best practices. On a theoretical level, however, connections have yet to be made between the literature of the sociology of natural disaster management and this newly organized field of Planetary Defense management. This dissertation aims to address this knowledge gap by extracting lessons learned and guidelines from the Sociology of Disaster Management and link them to the field of Planetary Defense management. / Dissertation/Thesis / Doctoral Dissertation Human and Social Dimensions of Science and Technology 2019

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.