Orbit Maneuver For Responsive Coverage Using Electric Propulsion,
2010
Air Force Institute of Technology
Orbit Maneuver For Responsive Coverage Using Electric Propulsion, Timothy S. Hall
Theses and Dissertations
The use of continuous electric propulsion to manipulate a satellite’s orbit offers significant potential for enhancing coverage of a target in ways not previously considered. Elliptical orbits utilizing a very low perigee can facilitate access to the surface and atmosphere of the Earth at sub-ionosphere altitudes while counteracting atmospheric drag forces using continuous electric propulsion. Additionally, in-plane and out-of-plane manipulation of both circular and elliptical orbits can allow for passage of a satellite over a target at a given time. Sustained low perigee orbit was modeled with an initial perigee altitude of 100 km and various apogee altitudes to derive …
Back-Pressure Effect On Shock-Train Location In A Scramjet Engine Isolator,
2010
Air Force Institute of Technology
Back-Pressure Effect On Shock-Train Location In A Scramjet Engine Isolator, Richard I. Paek
Theses and Dissertations
The isolator of the scramjet decelerates the incoming high Mach flow to a lower Mach number and stabilizes the flow before it enters the combustor. Because of the unsteady combustion phenomenon and inconsistent completeness of the combustion, pressures within the combustor can vary drastically. These pressure variations can propagate forward and affect the flow field in the isolator - worst case unstarting the inlet. In this research, the shock train location versus the back-pressure is examined experimentally. The back-pressure is artificially created by symmetric (top & bottom) ramps that can close the flow area. Raising/lowering ramps result in higher/lower back-pressure. …
Design Of A Film Cooling Experiment For Rocket Engines,
2010
Air Force Institute of Technology
Design Of A Film Cooling Experiment For Rocket Engines, Andrew L. Sincock
Theses and Dissertations
The Film Cooling Rig (FCR) is a new test rig at the Air Force Institute of Technology (AFIT) to study film cooling for rocket engine applications. The original researcher designed, built, and then utilized the FCR to study radial curvature effects on film cooling for a non-combustion environment. This effort modified the FCR by adding propane-air combustion. Modular stainless steel test sections were produced to allow study of various curvatures and coolant injection angles. A pre-mixed burner was designed and built to deliver main flow mass flow rates necessary to produce blowing ratios as low as 0.5. A water cooling …
Performance Of A Small Internal Combustion Engine Using N-Heptane And Iso-Octane,
2010
Air Force Institute of Technology
Performance Of A Small Internal Combustion Engine Using N-Heptane And Iso-Octane, Cary W. Wilson
Theses and Dissertations
With the sustained interest in Unmanned Aircraft Systems (UAS) and Micro Air Vehicles (MAV), the military services have a real need for vehicles powered by an internal combustion (IC) engine that can run efficiently on heavy hydrocarbon fuels, especially JP-8 due to established logistics. This thesis concerns the results of running a two horsepower, 4-stroke, spark-ignition engine (FUJI BF34-EI) with both iso-Octane and n-Heptane. Results include the knocking characteristic of this engine with n-Heptane, a comparison of the brake specific fuel consumption (BSFC) of the two fuels in a factory delivered engine configuration with a 17x10 APC propeller loading, a …
Analysis Of Hybrid-Electric Propulsion System Designs For Small Unmanned Aircraft Systems,
2010
Air Force Institute of Technology
Analysis Of Hybrid-Electric Propulsion System Designs For Small Unmanned Aircraft Systems, Ryan M. Hiserote
Theses and Dissertations
Currently fielded electric-powered small unmanned aircraft systems (UAS) lack the endurance desired by warfighters, while their internal combustion engine (ICE) driven counterparts generate mission compromising acoustic and thermal signatures. Parallel hybrid-electric propulsion systems would meet the military’s needs by combining the advantages of hydrocarbon and electric power systems. Three distinct parallel hybrid-electric system designs, each with three unique battery discharging profiles, were analyzed and compared using a constrained static optimization formulation based upon traditional aircraft design equations. Each system combined an ICE sized for cruise speed with an electric motor sized for endurance speed. The nine hybrid variations were compared …
Conceptual Design Tool For Fuel-Cell Powered Micro Air Vehicles,
2010
Air Force Institute of Technology
Conceptual Design Tool For Fuel-Cell Powered Micro Air Vehicles, Paul M. Hrad
Theses and Dissertations
A conceptual design tool was built to explore power requirements of a hybrid-power system for Micro Air Vehicles (MAVs) comparable in size to the Cooper's Hawk. An inviscid aerodynamic code, Athena Vortex Lattice (AVL), and a motor-propeller analysis code, QPROP, provide overall lift, drag, and thrust data for power-required calculation as functions of many variables to include mass, platform geometry, altitude, velocity, and mission duration. Phoenix Technologies’ Model Center was used to integrate multi-disciplinary components that employ specific power and specific energy of two power sources to determine power system mass required for a designated mission. The tool simulated a …
Off-Design Analysis Of A High Bypass Turbofan Using A Pulsed Detonation Combustor,
2010
Air Force Institute of Technology
Off-Design Analysis Of A High Bypass Turbofan Using A Pulsed Detonation Combustor, Caitlin R. Thorn
Theses and Dissertations
Past research has indicated that implementation of a pulsed detonation combustor (PDC) into a high-bypass turbofan engine yields a more efficient engine at design conditions. It is proposed that performance gains can be made utilizing this hybrid engine off-design. A hybrid high-bypass turbofan engine with a PDC model was evaluated for a range of Mach numbers, altitudes, and fill fractions in the Numerical Propulsion System Simulation (NPSS). Results were compared to a conventional baseline high-bypass turbofan engine that shares the same architecture with the hybrid. The NPSS baseline engine was validated using the Aircraft Engine Design System (AEDsys) program and …
Exfit Flight Design And Structural Modeling For Falconlaunch Viii Sounding Rocket,
2010
Air Force Institute of Technology
Exfit Flight Design And Structural Modeling For Falconlaunch Viii Sounding Rocket, Michael J. Vinacco
Theses and Dissertations
This research effort furthers the Air Force’s study of reusable launch vehicles and hypersonic airfoils by conducting a hypersonic flight test using the US Air Force Academy’s FalconLAUNCH VIII sounding rocket. In this study, two experimental fin tips were designed and attached to the sounding rocket in place of two stabilizer fins in order to collect data throughout the rocket’s hypersonic flight profile. The desire to research, study, and test experimental fin tips was driven by the Air Force Research Laboratory’s Future responsive Access to Space Technologies (FAST) program and their desire to include vertical stabilizers on the wing tips …
Minimizing Losses In A Space Laser Power Beaming System,
2010
Air Force Institute of Technology
Minimizing Losses In A Space Laser Power Beaming System, Charlie T. Bellows
Theses and Dissertations
A mathematical model is developed to track the amount of power delivered in a wireless laser power beaming system. In a wireless system the power proceeds through several different stages before being delivered to a payload for use. Each of these stages results in power losses that are thoroughly examined and modeled, allowing for the calculation of the likely amount of power delivered. Adjusting variable factors within the model allows for the optimization of the system for a specific task. The model shows that an optimized wireless power transfer system can deliver enough power to meet the space experiment objectives. …
Smore Phase 2: An Upgrade In Valve Systems & Startup Procedure For A Small Methanol Oxygen Liquid Rocket Engine,
2010
California Polytechnic State University, San Luis Obispo
Smore Phase 2: An Upgrade In Valve Systems & Startup Procedure For A Small Methanol Oxygen Liquid Rocket Engine, Christian Soria
Aerospace Engineering
A Methanol-Oxygen liquid rocket engine was designed and manufactured under the California Polytechnic State University Aerospace Department by students in a graduate level rocket propulsion class. The SMORE, previously known as the KORE, is now in an ongoing testing and developing stage with plans to incorporate it into the aerospace undergraduate propulsion lab. Phase 2 of the liquid rocket engine development is to produce a start-up procedure that will improve the safety due to manual operation and poor ignition conditions. A propane ignition system along with the implementation of electrically operated solenoid valves to control the fuels and oxidizer were …
Mixi Thruster Tungsten And Thoriated Tungsten Testing,
2010
California Polytechnic State University, San Luis Obispo
Mixi Thruster Tungsten And Thoriated Tungsten Testing, Jesse R. Miller
Aerospace Engineering
The purpose of this project is to build and evaluate a tungsten filament cathode for the 3-cm Miniature Xenon Ion (MiXI) thruster. The filament is to be used for future tests within the CP 3-cm MiXI and thoriated tungsten is to be examined as a possible alternative. No testing of these filaments was conducted, but the preparatory work has been conducted for future testing.
