Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Aircraft exhaust systems (1)
- Can combustor (1)
- Combustion chambers (1)
- Computer aided design (1)
- Continuous spin detonation (1)
-
- Drone aircraft (1)
- Electric propulsion (1)
- Electrolytic processes (1)
- Fuels (1)
- Hall effect devices (1)
- Infrared spectroscopy (1)
- Internal combustion engines (1)
- Jet engines--Combustion chambers (1)
- Microsatellites (1)
- Performance (engineering) (1)
- Plasma physics (1)
- Pyrometry (1)
- Rocket engines (1)
- Rocket propulsion (1)
- Spectrum analysis (1)
- Thermodynamics (1)
- Turbulent flow (1)
- Wave rotor (1)
Articles 1 - 7 of 7
Full-Text Articles in Engineering
The Scaling Of Loss Pathways And Heat Transfer In Small Scale Internal Combustion Engines, Joseph K. Ausserer
The Scaling Of Loss Pathways And Heat Transfer In Small Scale Internal Combustion Engines, Joseph K. Ausserer
Theses and Dissertations
Prior literature indicates fuel conversion efficiency and normalized power deteriorate increasingly rapidly with decreasing displacement, but does not fully reveal the driving losses. The literature also suggested that increasing losses relax the required fuel anti-knock index (AKI), but offered conflicting conclusions on the performance impact. This comprehensive experimental study of three, 28 cm3 to 85 cm3 displacement, commercial-off-the-shelf (COTS), two-stroke ICEs identified short-circuiting as having the most deleterious impact on COTS engine performance in this size range. Heat transfer losses were comparable to larger engines for displaced volumes greater than 10 cm3. An engine friction model was developed that uses …
Design, Manufacturing, And Testing Of A Small Through-Flow Wave For Use Within The Brayton Cycle, Micahel J. Mcclearn
Design, Manufacturing, And Testing Of A Small Through-Flow Wave For Use Within The Brayton Cycle, Micahel J. Mcclearn
Theses and Dissertations
With the ever growing popularity of drones and other unmanned aerial vehicles for military, commercial, and private usage, there is a desire to improve performance in terms of range, altitude, and flight speed. Current technology uses either electric motors or internal combustion engines: both piston and jet engine types. These sorts of engines undergo significant efficiency degradation as their size decreases. While some efficiency may be recovered via intensive design studies, the cycles are approaching the limit to their operating physics. A possible solution to this is to change the operating physics to something more immune to scaling losses; a …
Design And Experimentation Of A Premixed Rotating Detonation Engine, Ionio Q. Andrus
Design And Experimentation Of A Premixed Rotating Detonation Engine, Ionio Q. Andrus
Theses and Dissertations
Desire for a more efficient air breathing engine has shifted research attention to the Rotating Detonation Engine (RDE). Detonation is a more efficient combustion process than deflagration and provides a pressure gain. The RDE detonation cycle occurs in a compact volume to produce a high specific impulse engine. Computational fluid dynamic (CFD) models have predicted higher specific impulse and detonation wave speeds than has been seen in experimental RDE. The CFD models frequently assume premixed reactants and ignore inlet geometries to facilitate rapid computation. An experimental premixed RDE was sought to test if the premixed assumption in CFD was the …
Localized Plasma Measurement During Instability Modes In A Hall Thruster, David A. Cunningham
Localized Plasma Measurement During Instability Modes In A Hall Thruster, David A. Cunningham
Theses and Dissertations
Hall thrusters are a key technology for current and future unmanned satellites, striking a balance between thrust and fuel economy suitable for many mission profiles of interest. Despite their extensive flight heritage and a large body of research, many phenomena occurring in the plasma discharge of Hall thrusters are not well understood. A combination of intrusive and non-intrusive measurement techniques were used to investigate the properties of the exhaust plume of two Hall thrusters and correlate optical characteristics of oscillating modes with the plasma potential and azimuthal current distribution during those modes. A strong trend was found associating the optical …
Spectroscopic Measurement Of Gas Temperature In Small Internal Combustion Engines, Matthew J. Deutsch
Spectroscopic Measurement Of Gas Temperature In Small Internal Combustion Engines, Matthew J. Deutsch
Theses and Dissertations
The Small Engine Research Bench (SERB) was used previously to measure spatially and temporally averaged heat flux, as well as local, instantaneous heat flux at several external locations, for a series of small engines (1 - 10 kW). This investigation obtained time averaged crank angle resolved measurements of the in-cylinder gas temperature using Fourier transform infrared (FTIR) absorption thermometry. The results, coupled with heat flux measurements, will enable the validation or refinement of existing thermal energy loss models.
Enhanced Flow Migration In Full Annular Ultra Compact Combustor, Nicholas A. Gilbert
Enhanced Flow Migration In Full Annular Ultra Compact Combustor, Nicholas A. Gilbert
Theses and Dissertations
Since combustion efficiency in modern jet engines has stabilized, attention has turned to improving the combustor by improving the thrust-to-weight ratio. The Ultra Compact Combustor (UCC) is a means to reduce the weight of the combustor while ensuring exhaust meets increasingly stringent government emission standards. Combustion occurs within the UCC under a g-load in the circumferential direction, which maintains combustion efficiency while decreasing axial combustor length. Previous analysis optimized the combustion chamber flame characteristics with a common upstream air source. Previously, issues for the UCC were inspired by integration into a traditional axial turbojet. The focus of this investigation was …
Performance Testing Of Various Nozzle Design For Water Electrolysis Thruster, Yuen Liu
Performance Testing Of Various Nozzle Design For Water Electrolysis Thruster, Yuen Liu
Theses and Dissertations
The purpose of this research is to develop new nozzles for the HYDROSTM thruster, a pulsed chemical thruster, to improve the current flight performance. This research consists of a base line test of the factory nozzle, as well as testing of three 15-degree conical nozzles with different expansion ratios. Experiments were conducted at plenum pressures 30, 40, and 45 psia to ensure the thruster is throttleable. Impulse bit data was collected through measuring the impulse response of each firing using a torsional balance thrust stand. Analysis of the thruster performance included calculations of impulse bit, specific impulse, thrust coefficient, …