Gray Gas Analysis Of Radiative Preheating Effects On Shock Induced Combustion,
2012
Missouri University of Science and Technology
Gray Gas Analysis Of Radiative Preheating Effects On Shock Induced Combustion, Pratibha Raghunandan
Masters Theses
"The use of detonations in combustors has been receiving increased attention in recent times. The presence of shock waves in such combustors invariably poses the existence of two domains that present different physics for the flow processes. The variation of upstream temperature due to radiative heating by the products of combustion was given particular attention in the present study. The modeling of heat transfer across a normal shock wave of negligible thickness was done by considering the reactants and the products of combustion to be in radiative equilibrium with each other. The quantification of emissivity of the products of combustion …
Development Of Detailed Computational Flow Model Of High End Server And Validation Using Experimental Methods,
2012
University of Texas at Arlington
Development Of Detailed Computational Flow Model Of High End Server And Validation Using Experimental Methods, Vijayalayan Pandiyan
Mechanical and Aerospace Engineering Theses - Archive
The continued development of the microprocessor has led to significant increase in high frequency interconnects and power dissipation. High power devices are pushing the limits of air cooling in data center environments. Data center power consumption continues to grow at a rapid pace. In light of this increasing trend in power consumption, computer systems researchers, application designers, power and cooling engineers, and governmental bodies have all launched research efforts to improve data center energy efficiency [1]. Rack servers tend to be the main perpetrators of wasting energy and represent the largest portion of the IT energy load in a typical …
Experimental/Computational Analysis Of Active Cooling Of Stacked Device Using Multidimensional Configured Thermoelectric Modules,
2012
University of Texas at Arlington
Experimental/Computational Analysis Of Active Cooling Of Stacked Device Using Multidimensional Configured Thermoelectric Modules, Vaidehi Bharat Patel
Mechanical and Aerospace Engineering Theses - Archive
Stacked devices are currently used widely because of their smaller footprint and corresponding ability to accommodate heterogeneous devices such as memory and logic and enable a silicon efficiency greater than 100%. This configuration will results in thermal management challenges due to the torturous heat dissipation path. In addition, the non-uniformity in chip power distribution results in an increased spreading resistance as well as temperature gradient at the device level that can degrade performance and reliability. In this study the Thermoelectric Modules were configured in a multidimensional form surrounding a three dimensional cold core. The corresponding Computational Fluid Dynamics model is …
Large Scale Finite Element Analysis Using Gpu Parallel Computing,
2012
University of Texas at Arlington
Large Scale Finite Element Analysis Using Gpu Parallel Computing, Ashkan Akbariyeh
Mechanical and Aerospace Engineering Theses - Archive
In the past years, graphic processing units have become a new abundant parallelcomputing resource on personal computers. In this work parallel computation ofa typical case in nite element analysis for solids has been practiced. The solutionof 3-D linear elastic static problems with 3 degree of freedom is fully implementedutilizing the current GPU technology. Discretization of the problem has been donefor two cases of: Tetrahedral and Hexahedral elements. Acceleration of the solutionhas been realized using SIMT parallel algorithms. Sparse matrix storage formats aswell as matrix-vector operations are investigated for optimum hardware utilization.preconditioned conjugate gradient method has been fully implemented on the …
Protection Of Humanity’S Cultural And Historic Heritage In Space,
2012
Chapman University
Protection Of Humanity’S Cultural And Historic Heritage In Space, Justin St. P. Walsh
Art Faculty Articles and Research
While the international community has acted forcefully since World War II to protect sites and objects of cultural or historic significance on Earth, little attention has been paid to the same kinds of sites and objects in space. There are important ethical and scholarly reasons for wanting to preserve sites and in situ objects in off-Earth contexts from destruction or commercial exploitation. Innovative space research equipment, such as spacecraft, satellites, and space stations, and the locations of historic missions, such as Tranquility Base, therefore deserve formal international recognition and protection. Appropriate models for developing a comprehensive protective scheme can be …
Thermal Stability Characteristics Of Fisher-Tropsch And Hydroprocessed Alternative Aviation Fuels In A Fixed Bed Reactor,
2012
University of Central Florida
Thermal Stability Characteristics Of Fisher-Tropsch And Hydroprocessed Alternative Aviation Fuels In A Fixed Bed Reactor, Sergio Quintero
Electronic Theses and Dissertations
Growing prices, limited supply, and public concern about greenhouse gases associated with crude-derived jet fuels have led to development of renewable alternatives which must be compatible with the worldwide civilian and military aviation infrastructure, which were designed for operation with Jet-A/JP-8. Any alternative fuel should not have negative effects on the aircraft engines and fuel systems, especially from a thermal stability perspective, since any adverse effect of the physical properties, and chemical composition, including existence of trace elements, of those fuels may only be revealed after extensive operation, resulting in higher life-cycle maintenance and operation costs. This study considered four …
A Filter-Forcing Turbulence Model For Large Eddy Simulation Incorporating The Compressible "Poor Man's" Navier--Stokes Equations,
2012
University of Kentucky
A Filter-Forcing Turbulence Model For Large Eddy Simulation Incorporating The Compressible "Poor Man's" Navier--Stokes Equations, Joshua Strodtbeck
Theses and Dissertations--Mechanical and Aerospace Engineering
A new approach to large-eddy simulation (LES) based on the use of explicit spatial filtering combined with backscatter forcing is presented. The forcing uses a discrete dynamical system (DDS) called the compressible ``poor man's'' Navier--Stokes (CPMNS) equations. This DDS is derived from the governing equations and is shown to exhibit good spectral and dynamical properties for use in a turbulence model. An overview and critique of existing turbulence theory and turbulence models is given. A comprehensive theoretical case is presented arguing that traditional LES equations contain unresolved scales in terms generally thought to be resolved, and that this can only …
Design And Flight Testing Of A Warping Wing For Autonomous Flight Control,
2012
University of Kentucky
Design And Flight Testing Of A Warping Wing For Autonomous Flight Control, Edward Brady Doepke
Theses and Dissertations--Mechanical and Aerospace Engineering
Inflatable-wing Unmanned Aerial Vehicles (UAVs) have the ability to be packed in a fraction of their deployed volume. This makes them ideal for many deployable UAV designs, but inflatable wings can be flexible and don’t have conventional control surfaces. This thesis will investigate the use of wing warping as a means of autonomous control for inflatable wings. Due to complexities associated with manufacturing inflatable structures a new method of rapid prototyping deformable wings is used in place of inflatables to decrease cost and design-cycle time. A UAV testbed was developed and integrated with the warping wings and flown in a …
Low Reynolds Number Flow Field Modification Via Travelling Wave Actuation Of A Vertically Aligned Wire Array Surface,
2012
University of Kentucky
Low Reynolds Number Flow Field Modification Via Travelling Wave Actuation Of A Vertically Aligned Wire Array Surface, John C. Calhoun
Theses and Dissertations--Mechanical and Aerospace Engineering
Experiments were conducted to observe the effects of an active wire surface on low-Reynolds number Poiseuille flow. The objective was to evaluate the feasibility of actuating piezoelectric nanowires into a travelling wave motion in order to reduce wall shear stress in turbulent flows. Studies have shown that travelling wave motions introduced into the bounding wall of turbulent flow can reduce wall shear stress by disrupting the formation of drag-inducing coherent vortical structures. A Reynolds number scaled flow facility was designed to represent the near-wall region of turbulent flow. A wire surface was installed in the bounding wall and dynamically actuated …
Aerodynamics And Control Of A Deployable Wing Uav For Autonomous Flight,
2012
University of Kentucky
Aerodynamics And Control Of A Deployable Wing Uav For Autonomous Flight, Michael Thamann
Theses and Dissertations--Mechanical and Aerospace Engineering
UAV development and usage has increased dramatically in the last 15 years. In this time frame the potential has been realized for deployable UAVs to the extent that a new class of UAV was defined for these systems. Inflatable wing UAVs provide a unique solution for deployable UAVs because they are highly packable (some collapsing to 5-10% of their deployed volume) and have the potential for the incorporation of wing shaping. In this thesis, aerodynamic coefficients and aileron effectiveness were derived from the equations of motion of aircraft as necessary parameters for autonomous flight. A wind tunnel experiment was performed …
The Allen Telescope Array Search For Electrostatic Discharges On Mars,
2012
University of California, Berkley
The Allen Telescope Array Search For Electrostatic Discharges On Mars, Marin M. Anderson, Andrew P.V. Siemion, William C. Barott, Geoffery C. Bower, Gregory T. Delory, Imke De Pater, Dan Werthimer
Department of Electrical Engineering and Computer Science - Daytona Beach
The Allen Telescope Array was used to monitor Mars between 2010 March 9 and June 2, over a total of approximately 30 hr, for radio emission indicative of electrostatic discharge. The search was motivated by the report from Ruf et al. of the detection of non-thermal microwave radiation from Mars characterized by peaks in the power spectrum of the kurtosis, or kurtstrum, at 10 Hz, coinciding with a large dust storm event on 2006 June 8. For these observations, we developed a wideband signal processor at the Center for Astronomy Signal Processing and Electronics Research. This 1024 channel spectrometer calculates …
Numerical Study Of Pressure Fluctuations Due To High-Speed Turbulent Boundary Layers,
2012
Missouri Unviersity of Science and Technology
Numerical Study Of Pressure Fluctuations Due To High-Speed Turbulent Boundary Layers, Lian Duan, Meelan M. Choudhari, Minwei Wu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Direct numerical simulations (DNS) are used to examine the pressure fluctuations generated by fully developed turbulence in supersonic turbulent boundary layers with an emphasis on both pressure fluctuations at the wall and the acoustic fluctuations radiated into the freestream. The wall and freestream pressure fields are first analyzed for a zero-pressure gradient boundary layer with Mach 2.5 and Reynolds number based on momentum thickness of approximately 2835. The single and multi-point statistics reported include the wall pressure fluctuation intensities, frequency spectra, space-time correlations, and convection velocities. Single and multi-point statistics of surface pressure fluctuations show good agreement with measured data …
Biological Evaluation Of A Novel Tissue Engineering Scaffold Of Layered Double Hydroxides (Ldhs),
2012
Missouri University of Science and Technology
Biological Evaluation Of A Novel Tissue Engineering Scaffold Of Layered Double Hydroxides (Ldhs), Fateme Fayyazbakhsh, Mehran Solati-Hashjin, M. A. Shokrgozar, S. Bonakdar, Y. Ganji, N. Mirjordavi, S. A. Ghavimi, P. Khashayar
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Bone Tissue Engineering (BTE) Composed of Three Main Parts: Scaffold, Cells and Signaling Factors. Several Materials and Composites Are Suggested as a Scaffold for BTE. Biocompatibility is One of the Most Important Property of a BTE Scaffold. in This Work Synthesis of a Novel Nanocomposite Including Layered Double Hydroxides (LDH) and Gelatin is Carried Out and its Biological Properties Were Studied. the Co-Precipitation (PH=11) Method Was Used to Prepare the LDH Powder, using Calcium Nitrate, Magesium Nitrate and Aluminum Nitrate Salts as Starting Materials. the Resulted Precipitates Were Dried. X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron …
Simulation And Testing Of Polymer Electrolyte Membrane Fuel Cell Bipolar Plates Fabricated By Selective Laser Sintering,
2012
Missouri University of Science and Technology
Simulation And Testing Of Polymer Electrolyte Membrane Fuel Cell Bipolar Plates Fabricated By Selective Laser Sintering, M. Wu, Ming-Chuan Leu, N. Guo
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Polymer Electrolyte Membrane (PEM) fuel cell converts directly electrochemical energy into electricity. Flow channels in bipolar plates, a critical component of fuel cell, were designed, simulated and tested. the bipolar plate used a mixture of graphite materials and was fabricated using a Selective Laser Sintering (SLS) process. the fabricated green parts were carbonized at high temperatures and converted into brown parts. Infiltration of resin was used to enhance the electric conductivity and strength of the bipolar plate. Finite element simulations were performed to investigate the state of species (hydrogen, oxygen) in the channels and Gas Diffusion Layers (GDLs) for four …
Improving The Efficiency Of Turbocharged Spark Ignition Engines For Passenger Cars Through Waste Heat Recovery,
2012
Missouri University of Science and Technology
Improving The Efficiency Of Turbocharged Spark Ignition Engines For Passenger Cars Through Waste Heat Recovery, Alberto A. Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The turbocharged direct injection stoichiometric spark ignition gasoline engine has less than Diesel full load brake engine thermal efficiencies and much larger than Diesel penalties in brake engine thermal efficiencies reducing the load by throttling. This engine has however a much better power density, and therefore may operate at much higher BMEP values over driving cycles reducing the fuel economy penalty of the vehicle. This engine also has the advantage of the very well developed three-way catalytic converter after treatment to meet future emission regulations. in these engines the efficiency may be improved recovering the waste heat, but this recovery …
Energy Recovery In Passenger Cars,
2012
Missouri University of Science and Technology
Energy Recovery In Passenger Cars, Alberto A. Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The turbocharged direct injection stoichiometric spark ignition gasoline engine has less than diesel full load brake engine thermal efficiencies and much larger than diesel penalties in brake engine thermal efficiencies reducing the load. This engine has, however, a much better power density, and therefore may operate at much higher brake mean effective pressure (BMEP) values over driving cycles thus reducing the fuel economy penalty of the vehicle. This engine also has the advantage of the very well developed three-way catalytic (TWC) converter after treatment to meet future emission regulations. Replacement of fossil gasoline with renewable gasoline-like fuels has major advantages. …
Kers Braking For 2014 F1 Cars,
2012
Missouri University of Science and Technology
Kers Braking For 2014 F1 Cars, Alberto A. Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Small, high power density turbocharged engines coupled to kinetic energy recovery systems are one of the key areas of development for both passenger and racing cars. in passenger cars, the KERS may reduce the amount of thermal energy needed to reaccelerate the car following a deceleration recovering part of the braking energy. This translates in a first, significant fuel energy saving. Also considering the KERS torque boost increasing the total torque available to accelerate the car, large engines working at very low brake mean effective pressures and efficiencies over driving cycles may also be replaced by small higher power density …
The Key Ideas Of Mdw Viii: A Summary,
2012
University of Dayton
The Key Ideas Of Mdw Viii: A Summary, Aaron Altman, Clive L. Dym, Ray Hurwitz, John W. Wesner
Mechanical and Aerospace Engineering Faculty Publications
This paper summarizes and highlights the presentations and discussions that took place during Mudd Design Workshop VIII, ‘Design Education: Innovation and Entrepreneurship,’ at Harvey Mudd College. This paper also describes both the key ideas that emerged from the presentations and discussions of the participating engineering design educators, practitioners and researchers, and the methodology used to capture and retain those ideas. Additionally, this paper proposes a framework of design competencies that were created and evolved by the workshop’s participants as a response to a question posed at one of the workshop sessions: ‘What are the minimum design competencies students should learn …
Prevailing Torque Locking Feature Wear-Out,
2012
University of South Florida
Prevailing Torque Locking Feature Wear-Out, Adam Joseph Charles Zimandy
USF Tampa Graduate Theses and Dissertations
This thesis provides much needed representative sample data for reuse life of fully seated and torqued locknuts. Most national requirements for prevailing torque locking fasteners only specify unseated reuse life. This could create a potentially dangerous situation if unseated is misinterpreted for seated. This thesis provides comparative data for seated verses unseated configuration. Six aerospace, 3 all-metal and 3 nylon insert, and one non-aerospace locknuts were tested at preloads levels of unseated, 66%, 75%, and 85% of yield of bolt. The locknuts tested are MS21043-4, NAS1291-4, NAS1805-4, MS17825-4, MS21044D4, NAS1021N4, and Grade 8. A fixture was created in order to …
100% Lpg Long Haul Truck Conversion - Economy And Environmental Benefits,
2012
Missouri University of Science and Technology
100% Lpg Long Haul Truck Conversion - Economy And Environmental Benefits, Alberto A. Boretti, Charles Grummisch
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Advanced Vehicle Technologies (AVT), a Ballarat Australia based company, has developed the World's first diesel to 100% LPG conversion for heavy haul trucks. There is no diesel required or utilized on the trucks. the engine is converted with minimal changes into a spark ignition engine with equivalent power and torque of the diesel. the patented technology is now deployed in 2 Mercedes Actros trucks. the power output in engine dynamometer testing exceeds that of the diesel (in excess of 370 kW power and 2700 Nm torque). in on-road application the power curve is matched to the diesel specifications to avoid …
