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Full-Text Articles in Engineering
Scaling Study Of Wave Rotor Turbo-Normalization Of A Small Internal Combustion Engine, Brandon D. Smith
Scaling Study Of Wave Rotor Turbo-Normalization Of A Small Internal Combustion Engine, Brandon D. Smith
Theses and Dissertations
One issue facing small Remotely Piloted Aircraft engines is their ability to maintain performance at altitude. Since many of these aircraft use commercial off the shelf engines originally designed for radio controlled aircraft and lawn care implements, the reduced pressure environment significantly degrades the operability of the engine as the altitude increases. An option to overcome this difficulty is to supercharge the system; however most superchargers are designed for larger, typically automotive, engines. As a supercharger's size is decreased, there are large efficiency losses. Therefore, there is a need to accomplish this function on a smaller scale without. One option …
Unsteady Specific Work And Isentropic Efficiency Of A Radial Turbine Driven By Pulsed Detonations, Kurt P. Rouser
Unsteady Specific Work And Isentropic Efficiency Of A Radial Turbine Driven By Pulsed Detonations, Kurt P. Rouser
Theses and Dissertations
There has been longstanding government and industry interest in pressure-gain combustion for use in Brayton cycle based engines. Theoretically, pressure-gain combustion allows heat addition with reduced entropy loss. The pulsed detonation combustor (PDC) is a device that can provide such pressure-gain combustion and possibly replace typical steady deflagration combustors. The PDC is inherently unsteady, however, and comparisons with conventional steady deflagration combustors must be based upon time-integrated performance variables. In this study, the radial turbine of a Garrett automotive turbocharger was coupled directly to and driven, full admission, by a PDC in experiments fueled by hydrogen or ethylene. Data included …
Development And Testing Of A Rotating Detonation Engine Run On Hydrogen And Air, Jason C. Shank
Development And Testing Of A Rotating Detonation Engine Run On Hydrogen And Air, Jason C. Shank
Theses and Dissertations
Rotating detonation engines (RDEs) have the potential for greater efficiencies over conventional engines by utilizing pressure gain combustion. A new modular RDE (6 in diameter) was developed and successfully run on hydrogen and standard air. The RDE allows for variation of injection scheme and detonation channel widths. Tests provided the operational space of the new RDE as well as characterized detonation unsteadiness. It was found that a smaller equivalence ratio than previous was required to obtain continuous detonations. Also discovered was VCJ was reached in the RDE, but not sustained.
Cooling Requirements For The Ultra Compact Combuster, Donald D. Johnson
Cooling Requirements For The Ultra Compact Combuster, Donald D. Johnson
Theses and Dissertations
Over the past several years, AFIT and the Air Force Research Laboratory have collaboratively investigated a novel combustor system that is compact in design and has potential use in an inter-turbine burner system. The ultra-compact combustor (UCC) design wraps the combustion section circumferentially around the axial core flow and exploits the use of high-g combustion. The combustor's volume and weight are reduced by integrating the exit compressor vane and the turbine inlet vane. This creates a new hybrid vane that resides directly below the circumferential combustor. Recently, a computational effort to understand the fundamental aspects of the UCC on a …
Desensitizing Flame Structure And Exhaust Emissions To Flow Parameters In An Ultra-Compact Combuster, Adam K. Parks
Desensitizing Flame Structure And Exhaust Emissions To Flow Parameters In An Ultra-Compact Combuster, Adam K. Parks
Theses and Dissertations
A major thrust of turbine engine research is to improve both efficiency and thrust-to-weight ratio of the engine. A promising solution to this challenge is the Ultra-Compact Combustor (UCC). The UCC shortens the axial length of the combustor by performing combustion circumferentially on the outer diameter of the engine. The reduction in axial length yields significant weight savings and increases the thrust-to-weight ratio. The design also increases combustion efficiency by performing the combustion in a centrifugally loaded environment which allows unreacted particles to remain in the combustor sufficiently long enough to become combustion products. The Air Force Institute of Technology …
Build Up And Operation Of An Axial Turbine Driven By A Rotary Detonation Engine, Jonathan R. Tellefsen
Build Up And Operation Of An Axial Turbine Driven By A Rotary Detonation Engine, Jonathan R. Tellefsen
Theses and Dissertations
Detonation combustors provide advantages over current deflagration combustors due to their pressure gain and simplicity of design. Rotary detonation engines (RDEs) offer advantages over pulsed detonation engines (PDEs) due to a steadier exhaust and fewer total system losses. All previous research on turbine integration with detonation combustors has focused on utilizing PDEs to drive axial and centrifugal turbines. The objective of this thesis was the integration and testing of an axial turbine driven by a rotary detonation engine (RDE) to determine turbine operability. In pursuit of this objective, convergent nozzle sections were placed on the RDE to simulate the back-pressurization …