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Articles 1 - 30 of 77

Full-Text Articles in Mechanical Engineering

Sure Abstract - Spring 2019: Biomimetic Metamaterial Scales Enhancing Thermal Coatings’ Mechanical Properties For Turbine Blades, Ryan Horton Feb 2019

Sure Abstract - Spring 2019: Biomimetic Metamaterial Scales Enhancing Thermal Coatings’ Mechanical Properties For Turbine Blades, Ryan Horton

Ryan Horton

No abstract provided.


The Subject Librarian Newsletter, Engineering And Computer Science, Spring 2018, Buenaventura "Ven" Basco Oct 2018

The Subject Librarian Newsletter, Engineering And Computer Science, Spring 2018, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.


The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco Oct 2018

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.


Sure Abstract - Spring 2018: Analysis And Application Of Biomimetic Metamaterial Scales, Ryan Horton Feb 2018

Sure Abstract - Spring 2018: Analysis And Application Of Biomimetic Metamaterial Scales, Ryan Horton

Ryan Horton

No abstract provided.


Prediction Of Solid Oxide Fuel Cell Performance Using Artificial Neural Network, M. A. Rafe Biswas, Kamwana N. Mwara Oct 2017

Prediction Of Solid Oxide Fuel Cell Performance Using Artificial Neural Network, M. A. Rafe Biswas, Kamwana N. Mwara

M. A. Rafe Biswas

NASA’s Johnson Space Center has recently begun efforts to eventually integrate air-independent Solid Oxide Fuel Cell (SOFC) systems, with landers that can be propelled by LOX-CH4, for long duration missions. Using landers that utilize such propellants, provides the opportunity to use SOFCs as a power option, especially since they are able to process methane into a reactant through fuel reformation. Various lead-up activities, such as hardware testing and computational modelling, have been initiated to assist with this developmental effort.
One modeling approach, currently being explored to predict SOFC behavior, involves the usage of artificial neural networks (ANN). Since SOFC ...


Distillation-Resolved Evolution Of Key Combustion Properties, Jay A. Lefkowitz, Francis M. Haas Mar 2017

Distillation-Resolved Evolution Of Key Combustion Properties, Jay A. Lefkowitz, Francis M. Haas

Francis (Mac) Haas

Many studies demonstrate successful emulation of pre-vaporized real fuel combustion through use of fuel surrogates. These surrogates may be described by a multiplicity of non-unique multicomponent formulations, each with pre-vaporized combustion behaviors that are essentially equivalent to the target real fuel and each other. However, many combustion applications employ fuel sprays, leaving some question as to the validity of pre-vaporized assumptions for these conditions. In the present work, a batch distillation model for ideal liquids is developed to predict the evolution of surrogate fuel combustion properties such as autoignition propensity (represented by an effective RON or DCN), hydrogen-carbon-oxygen atomic ratios ...


Chemical Functional Group Descriptor For Jet Fuel Surrogate, Sang Hee Won, Francis M. Haas, Stephen Dooley, Frederick L. Dryer Mar 2017

Chemical Functional Group Descriptor For Jet Fuel Surrogate, Sang Hee Won, Francis M. Haas, Stephen Dooley, Frederick L. Dryer

Francis (Mac) Haas

The global chemical characters of complex chemical fuel mixtures are explicitly determined by evaluating the abundances of chemical functional groups present within it rather by applying molecular species composition. Statistical analyses on the relationships of each chemical functional group and the chemical property targets of the fuel are rigorously developed. The results demonstrate that the four CPTs currently used in surrogate formulation - H/C molar ratio, derived cetane number (DCN), average molecular weight (MW), and smoke point (SP) - effectively constrain the chemical function group distribution of the fuel, hence, the global combustion behaviors of pre-vaporized fuel/air mixtures. Emulating the ...


Simulation Model Of An Automatic Commercial Ice Machine, Haithem Murgham, David Myszka, Vijay Bahel, Rajan Rajendran, Kurt Knapke, Suresh Shivashankar, Kyaw Wynn Feb 2017

Simulation Model Of An Automatic Commercial Ice Machine, Haithem Murgham, David Myszka, Vijay Bahel, Rajan Rajendran, Kurt Knapke, Suresh Shivashankar, Kyaw Wynn

David Myszka

Automatic commercial ice-making machines that produce a batch of cube ice at regular intervals are known as “cubers." Such machines are commonly used in food service, food preservation, hotel, and health service industries. The machines are typically rated for the weight of ice produced over a 24-hour period at ambient air temperatures of 90°F and water inlet temperature of 70°F.

These cubers typically utilize an air-cooled, vapor-compression cycle to freeze circulating water flowing over an evaporator grid. Once a sufficient amount ice is formed, a valve switches to enable a harvest mode, where the compressor’s discharge gas ...


Studies Of Small Molecule Reactions Foundational To Combustion Chemistry, Francis M. Haas Oct 2016

Studies Of Small Molecule Reactions Foundational To Combustion Chemistry, Francis M. Haas

Francis (Mac) Haas

A high pressure laminar flow reactor facility (HPLFR) was designed and constructed to serve as a platform for the experimental study of the gas phase chemistry of small molecule species. This facility accommodates pressures from slightly above atmospheric to ~30 atm, temperatures from ambient to ~1000 K, and plug flow residence times on the order of 100 milliseconds to 10 seconds. Quasi-steady state NOx plateau (QSSP) experiments were conducted in the newly-constructed HPLFR to determine rate coefficients for the reaction H+O2(+M)↔HO2(+M) (H.9.M) relative to the reasonably well-known rate coefficient for H+NO2↔OH+NO ...


Industrial Solid-State Energy Harvesting: Mechanisms And Examples, Matthew Kocoloski, Carl Eger, Robin Mccarty, Kevin P. Hallinan, J. Kelly Kissock Sep 2016

Industrial Solid-State Energy Harvesting: Mechanisms And Examples, Matthew Kocoloski, Carl Eger, Robin Mccarty, Kevin P. Hallinan, J. Kelly Kissock

J. Kissock

This paper explores the potential for solid-state energy harvesting in industrial applications. In contrast to traditional heat recovery, the output of solid-state devices is electricity, which can be readily used in virtually any plant. The progress in harvesting waste heat via thermoelectric and thermionic generators is described. With second law efficiencies now approaching 50% and 80% respectively, we show that these technologies are on the cusp of practical use. Finally, we present an example of energy harvesting using thermionic devices in an industrial application. The example considers energy harvesting from a furnace at a glass manufacturing facility where exhaust gases ...


Energy Information Augmented Community-Based Energy Reduction, Kevin P. Hallinan, Harvey Enns, Stephenie Ritchey, Phil Brodrick, Nathan Lammers, Nichole Hanus, Mark Rembert, Tony Rainsberger Aug 2016

Energy Information Augmented Community-Based Energy Reduction, Kevin P. Hallinan, Harvey Enns, Stephenie Ritchey, Phil Brodrick, Nathan Lammers, Nichole Hanus, Mark Rembert, Tony Rainsberger

Harvey Enns

More than one-half of all U.S. states have instituted energy efficiency mandates requiring utilities to reduce energy use. To achieve these goals, utilities have been permitted rate structures to help them incentivize energy reduction projects. This strategy is proving to be only modestly successful in stemming energy consumption growth. By the same token, community energy reduction programs have achieved moderate to very significant energy reduction. The research described here offers an important tool to strengthen the community energy reduction efforts—by providing such efforts energy information tailored to the energy use patterns of each building occupant. The information provided ...


Microscale Investigation Of Thermo-Fluid Transport In The Transition Fil, Region Of An Evaporating Capillary Meniscus Using A Microgravity Environment, Kenneth D. Kihm, Jeffrey S. Allen, Kevin P. Hallinan, David M. Pratt Jul 2016

Microscale Investigation Of Thermo-Fluid Transport In The Transition Fil, Region Of An Evaporating Capillary Meniscus Using A Microgravity Environment, Kenneth D. Kihm, Jeffrey S. Allen, Kevin P. Hallinan, David M. Pratt

Kevin Hallinan

In order to enhance the fundamental understanding of thin film evaporation and thereby improve the critical design concept for two-phase heat transfer devices, microscale heat and mass transport is to be investigated for the transition film region using state-of-the-art optical diagnostic techniques. By utilizing a microgravity environment, the length scales of the transition film region can be extended sufficiently, from submicron to micron, to probe and measure the microscale transport fields which are affected by intermolecular forces. Extension of the thin film dimensions under microgravity will be achieved by using a conical evaporator made of a thin silicon substrate under ...


Nanocharacterization Of Bio-Silica Using Atomic Force And Ultrasonic Force Microscopy, Vinaypreet S. Gill, Kevin P. Hallinan, N. S. Brar Jul 2016

Nanocharacterization Of Bio-Silica Using Atomic Force And Ultrasonic Force Microscopy, Vinaypreet S. Gill, Kevin P. Hallinan, N. S. Brar

Kevin Hallinan

Nanotechnology has become central to our research efforts to fabricate relatively smaller size devices, which are more versatile than their older and larger predecessors. Silica is a very important material in this regard. Recently, a new biomimetically inspired path to silica production has been demonstrated. This processing technique was inspired from biological organisms, such as marine diatoms, which produce silica at ambient conditions and almost neutral ph with beautiful control over location and structure. Recently, several researchers have demonstrated that positional control of silica formed could be achieved by application of an electric field to locate charged enzymes responsible for ...


Leveraging Students’ Passion And Creativity: Ethos At The University Of Dayton, Margaret Pinnell, Malcolm Daniels, Kevin P. Hallinan, Gretchen Berkemeier Jul 2016

Leveraging Students’ Passion And Creativity: Ethos At The University Of Dayton, Margaret Pinnell, Malcolm Daniels, Kevin P. Hallinan, Gretchen Berkemeier

Kevin Hallinan

The Engineers in Technical Humanitarian Opportunities of Service-learning (ETHOS) program was developed in the spring of 2001 by an interdisciplinary group (electrical, chemical, civil and mechanical) of undergraduate engineering students at the University of Dayton (UD). ETHOS was founded on the belief that engineers are more apt and capable to appropriately serve our world if they have an understanding of technology’s global linkage with values, culture, society, politics, and the economy. Since 2001, the ETHOS program at UD has grown and changed. From conceptualization, to implementation, to maturation and national recognition, the program has addressed challenges of academic acceptance ...


Experimental Verification Of Source Temperature Modulation Via A Thermal Switch In Thermal Energy Harvesting, Robin Mccarty, D. Monaghan, Kevin P. Hallinan, Brian Sanders Jul 2016

Experimental Verification Of Source Temperature Modulation Via A Thermal Switch In Thermal Energy Harvesting, Robin Mccarty, D. Monaghan, Kevin P. Hallinan, Brian Sanders

Kevin Hallinan

This paper provides a description of research seeking to experimentally verify the effectiveness of a thermal switch used in series with TE devices for waste heat recovery for constant and variable source heat input and for variable source thermal capacitance (mass). Using an experimental set-up comprised serially of a fixed heat source, a variable thermal resistance air gap serving as a thermal switch, a thermoelectric device and a heat sink, the time-averaged power output to power input ratios improved up to 15% and 30% respectively for constant and variable heat input in certain design space conditions. The experimental results, as ...


Industrial Solid-State Energy Harvesting: Mechanisms And Examples, Matthew Kocoloski, Carl Eger, Robin Mccarty, Kevin P. Hallinan, J. Kelly Kissock Jul 2016

Industrial Solid-State Energy Harvesting: Mechanisms And Examples, Matthew Kocoloski, Carl Eger, Robin Mccarty, Kevin P. Hallinan, J. Kelly Kissock

Kevin Hallinan

This paper explores the potential for solid-state energy harvesting in industrial applications. In contrast to traditional heat recovery, the output of solid-state devices is electricity, which can be readily used in virtually any plant. The progress in harvesting waste heat via thermoelectric and thermionic generators is described. With second law efficiencies now approaching 50% and 80% respectively, we show that these technologies are on the cusp of practical use. Finally, we present an example of energy harvesting using thermionic devices in an industrial application. The example considers energy harvesting from a furnace at a glass manufacturing facility where exhaust gases ...


Energy Information Augmented Community-Based Energy Reduction, Kevin P. Hallinan, Harvey Enns, Stephenie Ritchey, Phil Brodrick, Nathan Lammers, Nichole Hanus, Mark Rembert, Tony Rainsberger Jul 2016

Energy Information Augmented Community-Based Energy Reduction, Kevin P. Hallinan, Harvey Enns, Stephenie Ritchey, Phil Brodrick, Nathan Lammers, Nichole Hanus, Mark Rembert, Tony Rainsberger

Kevin Hallinan

More than one-half of all U.S. states have instituted energy efficiency mandates requiring utilities to reduce energy use. To achieve these goals, utilities have been permitted rate structures to help them incentivize energy reduction projects. This strategy is proving to be only modestly successful in stemming energy consumption growth. By the same token, community energy reduction programs have achieved moderate to very significant energy reduction. The research described here offers an important tool to strengthen the community energy reduction efforts—by providing such efforts energy information tailored to the energy use patterns of each building occupant. The information provided ...


Electro-Hydrodynamic Pumped Hydraulic Actuation With Application To Active Vibration Control, Ahmad Reza Kashani, Sung Kang, Kevin P. Hallinan Jul 2016

Electro-Hydrodynamic Pumped Hydraulic Actuation With Application To Active Vibration Control, Ahmad Reza Kashani, Sung Kang, Kevin P. Hallinan

Kevin Hallinan

A new type of actuation device has been conceptualized that meets the needs of both large displacement, force and bandwidth within a package more compact than currently available magnetostrictive and stack-type piezoelectric actuators of similar rating. This concept relies on micro-scale electrohydrodynamic (EHD) pumping of a dielectric liquid within small channels. Configured as an actuator, the EHD pump(s) would be used to move fluid between two reservoirs—each having a compliant membrane that interfaces to the world to provide the means to achieve vibration cancellation or micro actuation. Ordinarily limited to generating flow in macroscale applications, the EHD pump ...


A Study Of The Fundamental Operations Of A Capillary Driven Heat Transfer Device In Both Normal And Low Gravity Part 1-Liquid Slug Formation In Low Gravity, Jeffrey S. Allen, Kevin P. Hallinan, Jack Lekan Jul 2016

A Study Of The Fundamental Operations Of A Capillary Driven Heat Transfer Device In Both Normal And Low Gravity Part 1-Liquid Slug Formation In Low Gravity, Jeffrey S. Allen, Kevin P. Hallinan, Jack Lekan

Kevin Hallinan

Research has been conducted to observe the operation of a capillary pumped loop (CPL) in both normal and low gravity environments in order to ascertain the causes of device failure. The failures of capillary pumped heat transport devices in low gravity; specifically; evaporator dryout, are not understood and the available data for analyzing the failures is incomplete. To observe failure in these devices an idealized experimental CPL was configured for testing in both a normal-gravity and a low-gravity environment. The experimental test loop was constructed completely of Pyrex tubing to allow for visualization of system operations. Heat was added to ...


Clean Energy Infrastructure Educational Initiative, Kevin P. Hallinan, James A. Menart, Robert Gilbert Jul 2016

Clean Energy Infrastructure Educational Initiative, Kevin P. Hallinan, James A. Menart, Robert Gilbert

Kevin Hallinan

The Clean Energy Infrastructure Educational Initiative represents a collaborative effort by the University of Dayton, Wright State University and Sinclair Community College. This effort above all aimed to establish energy related programs at each of the universities while also providing outreach to the local, state-wide, and national communities. At the University of Dayton, the grant has aimed at: solidfying a newly created Master's program in Renewable and Clean Energy; helping to establish and staff a regional sustainability organization for SW Ohio. As well, as the prime grantee, the University of Dayton was responsible for ensuring curricular sharing between WSU ...


Detailed And Compact Combustion Kinetic Models For Iso-Dodecane And Gevo Alcohol-To-Jet (Atj) Alternative Fuel, Francis M. Haas, Sang Hee Won, Frederick L. Dryer Feb 2016

Detailed And Compact Combustion Kinetic Models For Iso-Dodecane And Gevo Alcohol-To-Jet (Atj) Alternative Fuel, Francis M. Haas, Sang Hee Won, Frederick L. Dryer

Francis (Mac) Haas

Over a broad range of conditions and experimental configurations, recent experimental work has shown quantitative similarities between the pre-vaporized combustion behaviors of iso-dodecane (iC12: 2,2,4,6,6-pentamethylheptane), iso-octane (iC8: 2,2,4-trimethylpentane), iso-cetane (iC16: 2,2,4,4,6,8,8-heptamethylnonane), and a 50/50 (molar) iC8/iC16 mixture. Such similarity – typically within experimental uncertainties – suggests that these fuels share a significant subset of combustion chemistry related to fuel destruction into nearly equal fluxes of iso-C4 fragments. This proposition is used to develop a compact (43 species) kinetic model to describe iC12 combustion by using detailed chemistry models ...


Narrow-Linewidth Megahertz-Repetition-Rate Optical Parametric Oscillator For High-Speed Flow And Combustion Diagnostics, Naibo Jiang, Walter R. Lempert, Gary L. Switzer, Terrence R. Meyer, James R. Gord Nov 2015

Narrow-Linewidth Megahertz-Repetition-Rate Optical Parametric Oscillator For High-Speed Flow And Combustion Diagnostics, Naibo Jiang, Walter R. Lempert, Gary L. Switzer, Terrence R. Meyer, James R. Gord

Terrence R Meyer

We demonstrate the ability to generate ultra-high-frequency sequences of broadly wavelength-tunable, high-intensity laser pulses using a custom-built optical parametric oscillator pumped by the thirdharmonic output of a "burst-mode" Nd:YAG laser. Burst sequences consisting of 6-10 pulses separated in time by 6-10 Îs are obtained, with average total conversion efficiency from the 355 nm pump to the near-IR signal and idler wavelengths of 33%. Typical individual pulse output energy for the signal and idler beams is in the range of 4-6 mJ, limited by the available pump energy. Line narrowing is demonstrated by means of injection seeding the idler wave ...


Comparison Of Line-Peak And Line-Scanning Excitation In Two-Color Laser-Induced-Fluorescence Thermometry Of Oh, Stanislav Kostka, Sukesh Roy, Patrick J. Lakusta, Terrence R. Meyer, Michael W. Renfro, James R. Gord, Richard Branam Nov 2015

Comparison Of Line-Peak And Line-Scanning Excitation In Two-Color Laser-Induced-Fluorescence Thermometry Of Oh, Stanislav Kostka, Sukesh Roy, Patrick J. Lakusta, Terrence R. Meyer, Michael W. Renfro, James R. Gord, Richard Branam

Terrence R Meyer

Two-line laser-induced-fluorescence (LIF) thermometry is commonly employed to generate instantaneous planar maps of temperature in unsteady flames. The use of line scanning to extract the ratio of integrated intensities is less common because it precludes instantaneous measurements. Recent advances in the energy output of high-speed, ultraviolet, optical parameter oscillators have made possible the rapid scanning of molecular rovibrational transitions and, hence, the potential to extract information on gas-phase temperatures. In the current study, two-line OH LIF thermometry is performed in a wellcalibrated reacting flow for the purpose of comparing the relative accuracy of various line-pair selections from the literature and ...


Mhz-Rate Nitric Oxide Planar Laser-Induced Fluorescence Imaging In A Mach 10 Hypersonic Wind Tunnel, Naibo Jiang, Matthew Webster, Walter R. Lempert, Joseph D. Miller, Terrence R. Meyer, Christopher B. Ivey, Paul M. Danehy Nov 2015

Mhz-Rate Nitric Oxide Planar Laser-Induced Fluorescence Imaging In A Mach 10 Hypersonic Wind Tunnel, Naibo Jiang, Matthew Webster, Walter R. Lempert, Joseph D. Miller, Terrence R. Meyer, Christopher B. Ivey, Paul M. Danehy

Terrence R Meyer

Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1 MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 timecorrelated image sequences of between 10 and 20 individual frames were obtained over eight days of wind tunnel testing spanning two entries in March and September of 2009. The image sequences presented were obtained from the boundary layer of a 20° flat plate model, in which transition was induced using a variety of different shaped protuberances, including a cylinder and a triangle. The high-speed image sequences captured a variety ...


Simultaneous High-Speed Measurement Of Temperature And Lifetime-Corrected Oh Laserinduced Fluorescence In Unsteady Flames, Terrence R. Meyer, Galen B. King, Matthew Glusenkamp, James R. Gord Nov 2015

Simultaneous High-Speed Measurement Of Temperature And Lifetime-Corrected Oh Laserinduced Fluorescence In Unsteady Flames, Terrence R. Meyer, Galen B. King, Matthew Glusenkamp, James R. Gord

Terrence R Meyer

A means of performing simultaneous, high-speed measurements of temperature and OH lifetime-corrected laser-induced fluorescence (LIF) for tracking unsteady flames has been developed and demonstrated. The system uses the frequency-doubled and frequency-tripled output beams of an 80 MHz mode-locked Ti:sapphire laser to achieve ultrashort laser pulses (order 2 ps) for Rayleigh-scattering thermometry at 460 nm and lifetime-corrected OH LIF at 306.5 nm, respectively. Simultaneous, high-speed measurements of temperature and OH number density enable studies of flame chemistry, heat release, and flame extinction in unsteady, strained flames where the local fluorescence-quenching environment is unknown.


Single-Shot Gas-Phase Thermometry Using Purerotational Hybrid Femtosecond/Picosecond Coherent Anti-Stokes Raman Scattering, Joseph D. Miller, Sukesh Roy, Mikhail N. Slipchenko, James R. Gord, Terrence R. Meyer Nov 2015

Single-Shot Gas-Phase Thermometry Using Purerotational Hybrid Femtosecond/Picosecond Coherent Anti-Stokes Raman Scattering, Joseph D. Miller, Sukesh Roy, Mikhail N. Slipchenko, James R. Gord, Terrence R. Meyer

Terrence R Meyer

High-repetition-rate, single-laser-shot measurements are important for the investigation of unsteady flows where temperature and species concentrations can vary significantly. Here, we demonstrate singleshot, pure-rotational, hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps RCARS) thermometry based on a kHz-rate fs laser source. Interferences that can affect nanosecond (ns) and ps CARS, such as nonresonant background and collisional dephasing, are eliminated by selecting an appropriate time delay between the 100-fs pump/Stokes pulses and the pulse-shaped 8.4-ps probe. A time- and frequency-domain theoretical model is introduced to account for rotational-level dependent collisional dephasing and indicates that the optimal probe-pulse time ...


Quantitative Time-Averaged Gas And Liquid Distributions Using X-Ray Fluorescence And Radiography In Atomizing Sprays, Christopher D. Radke, J. Patrick Mcmanamen, Alan L. Kastengren, Benjamin R. Halls, Terrence R. Meyer Nov 2015

Quantitative Time-Averaged Gas And Liquid Distributions Using X-Ray Fluorescence And Radiography In Atomizing Sprays, Christopher D. Radke, J. Patrick Mcmanamen, Alan L. Kastengren, Benjamin R. Halls, Terrence R. Meyer

Terrence R Meyer

A method for quantitative measurements of gas and liquid distributions is demonstrated using simultaneous x-ray fluorescence and radiography of both phases in an atomizing coaxial spray. Synchrotron radiation at 10.1 keV from the Advanced Photon Source at Argonne National Laboratory is used for x-ray fluorescence of argon gas and two tracer elements seeded into the liquid stream. Simultaneous time-resolved x-ray radiography combined with timeaveraged dual-tracer fluorescence measurements enabled corrections for reabsorption of x-ray fluorescence photons for accurate, line-of-sight averaged measurements of the distribution of the gas and liquid phases originating from the atomizing nozzle.


Compact Kinetic Models For Typical And Alternative Aviation Turbine Fuels And Their Surrogates, Sang Hee Won, Jeffrey S. Santner, Francis M. Haas, Frederick L. Dryer, Stephen Dooley Apr 2015

Compact Kinetic Models For Typical And Alternative Aviation Turbine Fuels And Their Surrogates, Sang Hee Won, Jeffrey S. Santner, Francis M. Haas, Frederick L. Dryer, Stephen Dooley

Francis (Mac) Haas

Computational combustor design and analysis demands combustion kinetic models that are sufficiently compact in species number so that they can be used in multi-dimensional reacting computational fluid dynamics (CFD) simulations. These models ideally predict dynamic global combustion behaviors and emissions as faithfully as detailed kinetic models, but with significantly lower computational costs than even “reduced” models. Another aspect of computational engine analysis is the need to predict combustion and emissions behaviors resulting from variations in fuel composition, which is likely to increase as alternative fuels are used displace/replace conventional petro-derived aviation kerosenes. Accordingly, this work discusses a general methodology ...


Rate Coefficients For H+No2→Oh+No From High Pressure Flow Reactor Experiments, Francis M. Haas, Frederick L. Dryer Apr 2015

Rate Coefficients For H+No2→Oh+No From High Pressure Flow Reactor Experiments, Francis M. Haas, Frederick L. Dryer

Francis (Mac) Haas

Rate coefficients for the reaction H+NO2 → OH+NO (R1) were determined over the
nominal temperature and pressure ranges of 737-882 K and 10-20 atm, respectively, from spatially
resolved measurements in two different flow reactor facilities: one laminar and one turbulent. The
title reaction is important in a variety of situations including NO↔NO2 interconversion in the
power extraction stage of gas turbines, exhaust gas recirculation (EGR)-affected ignition in
reciprocating engines, and for H atom titration in elementary gas phase kinetics experiments. This
work determines absolute values of k1 with reference to the relatively well known rate coefficients
for ...


The Use Of Additive Manufacturing For Cubesat Design And Testing, Jeremy Straub, Ronald Marsh, Scott Kerlin Apr 2015

The Use Of Additive Manufacturing For Cubesat Design And Testing, Jeremy Straub, Ronald Marsh, Scott Kerlin

Jeremy Straub

In developing a small spacecraft, the integration of numerous systems in a small area is a key challenge. It is easy to overlook how various component parts will integrate or have multiple sub-groups utilize un-filled space without realizing that they are creating a resource conflict. Additionally, the manufacturability of the final design is a key consideration. For all of these reasons, developing low-cost and incremental prototypes is a engineering ‘best practice’ for small spacecraft development.