Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 97 for “"Propulsion and Power"”.
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Collimation of deuterium / 3-helium fusion products for advanced spacecraft propulsion and power
… transpired through the use of chemical rockets, and they have served us well, but they have their limitations. Exploration of the outer solar system, Jupiter and beyond will most likely require a new generation of propulsion system. One potential technology class to provide spacecraft propulsion …
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Optimal motion of a vertically sculling hydrofoil system for efficient propulsion and power extraction
… Institute of Technology, Dept. of Aeronautics and Astronautics, 2003.
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Definition, expansion and screening of architectures for planetary exploration class nuclear electric propulsion and power systems
Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2003.
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Active combustion control : modeling, design and implementation
Continuous combustion systems common in propulsion and power generation applications are susceptible to thermoacoustic instability, which occurs under lean burn conditions close to the flammability where most emissions and efficiency benefits are achieved, and near stoichiometry where often high …
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THERMAL MANAGEMENT OF ROTATING DETONATION ENGINES
… to the immense academic progress on the topic and its prospective commercial viability, particularly in relation to aerospace propulsion and power generation systems. One of the major outstanding barriers towards realizing practical RDEs is the issue of intensive heating of the combustor walls. …
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Application of a Non-intrusive Optical Non-spherical Particle Sizing Sensor at Turboshaft Engine Inlet
… environments. Ingesting particulates such as sand or dust can erode and damage engine components. This damage will affect the life cycle of parts and compromise the safety of the aircraft. This issue is very costly and dangerous. In order to combat these issues, a particle sensor with the …
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HAPSS, Hybrid Aircraft Propulsion System Synthesis
<p>Hybrid Aircraft Propulsion System Synthesis (HAPSS) is a computer program that sizes and analyzes pure-series hybrid electric propulsion systems for aircraft. The development of this program began during a NASA SBIR contract, in conjunction with Empirical Systems Aerospace (ESAero), with the …
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Suppression of premixed combustion dynamics utilizing microjet air injection
… systems is a major challenge in the field of propulsion and power generation. With the current environmental and political pressure that is being placed on the consumption of fossil fuels, this subject has become even more critical. In the past, the presence of combustion instability could be …
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Investigation of condensed and early stage gas phase hypergolic reactions
… flown in 1981, feature hydrazine based fuels and nitrogen tetroxide (NTO) based oxidizers. Despite the long history of hypergolic propellant implementation, the processes that govern hypergolic ignition are not well understood. In order to achieve ignition, condensed phase fuel and oxidizer …
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Development of mesoscale burner arrays for next generation compact gas turbines
… flexibly accommodate a wide range of combustion power outputs. The combustion characteristics of the mesoscale burner array were experimentally investigated using several optical diagnostic and analysis techniques. Lean blow off limit, flame temperature, and NO emission measurements were …
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Management and control of energy storage systems for stationary and automotive applications
… 1), reference has been made to some stationary and automotive applications. Stationary applications have regarded Renewable Energy Sources (RESs) exploitation issues and EV integration within micro-grids (Chapter 2). It has been shown that ESSs are particularly useful in compensating for RES …
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Investigation of Passive Flow Modulation for Full-Scale Air-Oil Coolers for Turbofan Engine Applications
… aircraft are used every day to transport people and goods around the world. For this reason, a need has been created to improve the thrust specific fuel consumption and improve the fuel efficiency of the engines used for these aircraft. To further improve the efficiency of the turbofan engine …
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Development of a High Performance Micropropulsion System for CubeSats
… defined as satellites with a mass between 0.1 and 1kg (Miniaturized satellite). Picosatellites are typically designed to work together or function in formations (Miniaturized satellite). A specific type of Picosatellite known as CubeSats were introduced in 1999 and since then have increased in …
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Comparative simulations of conceptual ion extractors for use in asymmetric inertial electrostatic confinement
Many deep space propulsion missions currently use ballistic trajectories to reach their destinations. To reduce the times of flight, electric or plasma based propulsion systems are used. While Hall Effect thrusters are the general standard for plasma propulsion, new technologies can enable shorter …
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Suppression of thermoacoustic instabilities in a swirl combustor through microjet air injection
… feedback loop coupling heat release rate and acoustic oscillations in a combustor, is one of the greatest challenges currently facing the development of new gas turbine systems for propulsion and power generation. Traditional gas turbine designs have bypassed the problem of combustion …
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The Effect of Thermal Non-Uniformity on Coherent Structures in Supersonic Free Jets
… noise, with little modification to the engine and nozzle. Prior work has shown that total temperature non-uniformity is a noise reduction technique which introduces a stream of cold flow into the heated jet. This method has been shown to cause changes in the exhaust plume and result in a 2±0.5 …
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Prediction of Noise Associated with an Isolated UAV Propeller
… generation mechanism of a propeller as a mode of propulsion of the said aerial vehicles. Numerical simulation utilizing a Hybrid Large-Eddy Simulation (LES) coupled with Unsteady Reynolds-Averaged Navier-Stokes (RANS) solver, is adopted on an isolated propeller modeled from the commercial DJI …
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Unsteady Internal Ballistics of a Hybrid Rocket
… simplicity, low cost, operational flexibility, and safety. The flow in the ports of a hybrid rocket motor involves several coupled unsteady phenomena like moving walls, combustion in a boundary layer flow and mass addition along the port, through the regression of the solid fuel wall. The flow …
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Optimal Battery Weight Fraction for Serial Hybrid Propulsion System in Aircraft Design
<p>This thesis focuses on electric propulsion technology associated with serial hybrid power plants most commonly associated with urban air mobility vehicles. While closed form analytical solutions for parallel hybrid aviation cases have been determined, optimized serial hybrid power plants have …
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Method and Simulation of On-Orbit Sub-microthrust Evaluation
… μN precision attitude control for interferometry and imaging missions, finer micro- to sub-micro- thrusters have become an area of high interest. As thrusters are developed and ground-tested, it is necessary to evaluate their thrust performance on-orbit. On-orbit measurements offer actual thrust …
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