Assessment Of High Cycle Fatigue Crack Growth Under Different Stages Based On Crystal Plasticity Modeling, 2016 Beihang University; Collaborative Innovation Center of Advanced Aero-engine
Assessment Of High Cycle Fatigue Crack Growth Under Different Stages Based On Crystal Plasticity Modeling, Duoqi Shi, Shiwei Han, Xiaoguang Yang
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Anisoplanatic Electromagnetic Image Propagation Through Narrow Or Extended Phase Turbulence Using Altitude-Dependent Structure Parameter, 2016 University of Dayton
Anisoplanatic Electromagnetic Image Propagation Through Narrow Or Extended Phase Turbulence Using Altitude-Dependent Structure Parameter, Monish Ranjan Chatterjee, Ali Mohamed
Electrical and Computer Engineering Faculty Publications
The effects of turbulence on anisoplanatic imaging are often modeled through the use of a sequence of phase screens distributed along the optical path. We implement the split-step wave algorithm to examine turbulence-corrupted images.
Climb Performance Of Business Jets, 2016 Minnesota State University, Mankato
Climb Performance Of Business Jets, Nihad E. Daidzic
Aviation Department Publications
No abstract provided.
The Scaling Of Loss Pathways And Heat Transfer In Small Scale Internal Combustion Engines, 2016 Air Force Institute of Technology
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 …
Numerical Investigations Of A High Frequency Pulsed Gaseous Fuel Jet Injection Into A Supersonic Crossflow, 2016 University of Tennessee, Knoxville
Numerical Investigations Of A High Frequency Pulsed Gaseous Fuel Jet Injection Into A Supersonic Crossflow, Nehemiah Joel Williams
Doctoral Dissertations
The investigation of fuel delivery mechanisms is a critical design point in the development of supersonic combustion ramjet (scramjet) technology. Primary challenges include proper penetration of the jet in the supersonic cross-flow while keeping total pressure losses and wall drag to a minimum. To reduce drag and heat loads especially at high burner entry Mach numbers it is desirable to use a minimally intrusive means of fuel delivery.
Pulsation of gaseous jets has been shown to increase penetration and mixing in subsonic flows. A limited number of experimental studies and even fewer numerical studies have suggested that when applied to …
Design And Experimentation Of A Premixed Rotating Detonation Engine, 2016 Air Force Institute of Technology
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 …
Design, Manufacturing, And Testing Of A Small Through-Flow Wave For Use Within The Brayton Cycle, 2016 Air Force Institute of Technology
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 …
Electrically Coupled Counter-Rotation For Gas Turbine Compressors, 2016 Embry-Riddle Aeronautical University
Electrically Coupled Counter-Rotation For Gas Turbine Compressors, Vinod Gehlot
Publications
A system and method for implementing stage-by-stage counter rotation in a multi-stage axial compressor of a gas turbine engine. The system includes an electrical power generator and an electric motor. A turbine-driven shaft connected to an armature of the electrical generator drives a first plurality of compressor blades. The electrical generator armature induces changing magnetic flux in the stator coils of the electrical generator which generates electrical power that is sent to a power control module. The power control module controls the electrical motor and excites the coils in the electric motor stator which drives the electric motor armature. The …
Estimation Of Performance Airspeeds For High-Bypass Turbofans Equipped Transport-Category Airplanes, 2016 AAR Aerospace Consulting, LLC
Estimation Of Performance Airspeeds For High-Bypass Turbofans Equipped Transport-Category Airplanes, Nihad E. Daidzic
Journal of Aviation Technology and Engineering
Conventional Mach-independent subsonic drag polar does not replicate the real airplane drag characteristics exactly and especially not in the drag-divergence region due to shock-induced transonic wave drag. High-bypass turbofan thrust is a complicated function of many parameters that eludes accurate predictions for the entire operating envelope and must be experimentally verified. Fuel laws are also complicated functions of many parameters which make optimization and economic analysis difficult and uncertain in the conceptual design phase. Nevertheless, mathematical models and predictions have its important place in aircraft development, design, and optimization. In this work, airspeed-dependent turbofan thrust and the new fuel-law model …
Multi-Stage Axial Compressor With Counter-Rotation Using Accessory Drive, 2016 Embry-Riddle Aeronautical University
Multi-Stage Axial Compressor With Counter-Rotation Using Accessory Drive, Vinod Gehlot, Magdy S. Attia
Publications
A multi-stage axial compressor for counter rotation. A first series of rotor blade assemblies are mounted on and rotate with the driveshaft, each rotor blade assembly of the first series comprising a rotating stage of the multi-stage axial compressor. A second series of rotor blade assemblies provide a counter-rotating stage of the multi-stage axial compressor. An accessory drive links the second series of rotor blade assemblies to the driveshaft and causes counter-rotation of the second series of rotor blade assemblies.
Control System Requirements For A Nuclear Thermal Propulsion System, 2016 University of Tennessee, Knoxville
Control System Requirements For A Nuclear Thermal Propulsion System, Adam Hasse, Michael Smith, Bradley Pershke, Andrew Adams, Stephen GilliAm
Chancellor’s Honors Program Projects
No abstract provided.
Computational Investigation Of Impingement Cooling For Regeneratively Cooled Rocket Nozzles, 2016 Embry-Riddle Aeronautical University
Computational Investigation Of Impingement Cooling For Regeneratively Cooled Rocket Nozzles, Bianca A. De Angelo
Doctoral Dissertations and Master's Theses
Jet impingement cooling is an internal cooling configuration used in the thermal management of temperature sensitive systems. With rocket engine combustion temperatures rising as high as 3600 K, it is essential for a cooling method to be applied to ensure that the nozzle integrity can be maintained. Therefore, a novel heat transfer study is conducted to investigate if jet impingement cooling is feasible for a regenerative cooling rocket nozzle application. Regenerative cooling for liquid propellant rockets has been widely studied. However, to the best of the author’s knowledge, there is currently no literature describing this method in conjunction with impingement …
Time-Of-Flight Based Sonic Speed Measurements For Cold Gas Thruster Development, 2016 University of Arkansas, Fayetteville
Time-Of-Flight Based Sonic Speed Measurements For Cold Gas Thruster Development, Brandon W. Kempf
Mechanical Engineering Undergraduate Honors Theses
The purpose of this thesis is to explore an experiment developed for validating the usage of a gaseous solution of water and propylene glycol for cold gas propulsion. The experiment involves a “Time of Flight” method of calculating the speed of sound in the gas and the corresponding specific heat ratio using a copper tube, two MEMS microphones, a piezoelectric speaker, and data-acquisition hardware. The experiment was calibrated using the known thermodynamic properties of air. The accuracy of the experiment was found to be within 0.6% for calculations of the speed of sound in air and within 1.0% of the …
Spectroscopic Measurement Of Gas Temperature In Small Internal Combustion Engines, 2016 Air Force Institute of Technology
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.
Performance Testing Of Various Nozzle Design For Water Electrolysis Thruster, 2016 Air Force Institute of Technology
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, …
Enhanced Flow Migration In Full Annular Ultra Compact Combustor, 2016 Air Force Institute of Technology
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 …
Localized Plasma Measurement During Instability Modes In A Hall Thruster, 2016 Air Force Institute of Technology
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 …
Hybrid Clutch Assembly For An Aircraft, 2016 Embry-Riddle Aeronautical University
Hybrid Clutch Assembly For An Aircraft, Richard Anderson, Charles N. Eastlake, Matt Gonitzke, Glenn P. Greiner
Publications
A hybrid clutch assembly inserted between an internal combustion engine and the propeller of an aircraft to provide a hybrid-powered aircraft. The hybrid clutch assembly allows a direct current (DC) electric motor to be attached to the hybrid clutch assembly using drive belts. The hybrid clutch assembly allows the internal combustion engine to transmit power to the aircraft's propeller and freely spin the DC motor. The DC motor can transmit power to the aircraft's propeller without turning the internal combustion engine. The hybrid clutch assembly independently allows either the internal combustion engine or the DC motor in parallel to power …
Determining The Runway Point-Of-No-Return For Landing Roll Go-Around In Transport Category Airplanes, 2016 Minnesota State University, Mankato
Determining The Runway Point-Of-No-Return For Landing Roll Go-Around In Transport Category Airplanes, Nihad E. Daidzic
Aviation Department Publications
No abstract provided.
Early Afternoon Concurrent Panel Sessions: Commercial Space Industry Snapshot: Presentation: Small Catapult-Assisted Horizontal-Launch Reusable Rbcc Ssto Spaceplane For Economical Short-Duration Leo Access, 2016 AAR Aerospace Consulting, LLC
Early Afternoon Concurrent Panel Sessions: Commercial Space Industry Snapshot: Presentation: Small Catapult-Assisted Horizontal-Launch Reusable Rbcc Ssto Spaceplane For Economical Short-Duration Leo Access, Nihad E. Daidzic,
Aviation / Aeronautics / Aerospace International Research Conference
This article discusses the conceptual design, flight trajectory calculations, and utilization of the possible future horizontally-launched reusable Single-Stage-to-Orbit (SSTO) spaceplane for small payload short-duration manned/unmanned access to Low-Earth-Orbit (LEO). The 10,000 lb spaceplane would use 5,000 ft catapult-assist horizontal-launch facility and conduct powered approach and landing on conventional horizontal paved runways following the gliding atmospheric re-entry. To increase the economy of operation, the launch facility located at high elevations (4,000+ ft) equatorial region is required, such as, the plateaus in Kenya and Tanzania in Africa and/or Ecuador in South America. A 500-lb payload, including pilot-commander, is envisioned. The propulsion cycle …