Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (41177)
- Civil and Environmental Engineering (40078)
- Electrical and Computer Engineering (37154)
- Mechanical Engineering (30237)
- Computer Engineering (25753)
-
- Computer Sciences (17452)
- Materials Science and Engineering (16791)
- Chemical Engineering (14259)
- Operations Research, Systems Engineering and Industrial Engineering (13954)
- Civil Engineering (11839)
- Biomedical Engineering and Bioengineering (11559)
- Aerospace Engineering (11196)
- Education (8228)
- Social and Behavioral Sciences (8048)
- Environmental Sciences (7007)
- Life Sciences (6360)
- Arts and Humanities (6255)
- Environmental Engineering (6148)
- Transportation Engineering (5937)
- Engineering Science and Materials (5758)
- Electrical and Electronics (5738)
- Energy Systems (5672)
- Artificial Intelligence and Robotics (5498)
- Other Mechanical Engineering (5100)
- Medicine and Health Sciences (4772)
- Geotechnical Engineering (4598)
- Mining Engineering (4591)
- Construction Engineering and Management (4479)
- Business (4370)
- Institution
-
- Missouri University of Science and Technology (21775)
- University of Nebraska - Lincoln (11227)
- California Polytechnic State University, San Luis Obispo (7990)
- University of Kentucky (6356)
- Purdue University (6335)
-
- Air Force Institute of Technology (5742)
- Utah State University (5452)
- Brigham Young University (4860)
- Old Dominion University (4742)
- University of Central Florida (4636)
- Technological University Dublin (4619)
- New Jersey Institute of Technology (4346)
- China Simulation Federation (3924)
- Chulalongkorn University (3655)
- Wright State University (3445)
- Embry-Riddle Aeronautical University (3313)
- University of Texas at Arlington (3185)
- TÜBİTAK (3106)
- Engineering Conferences International (2957)
- University of Arkansas, Fayetteville (2904)
- Louisiana State University (2841)
- Portland State University (2813)
- Michigan Technological University (2632)
- Clemson University (2609)
- University of South Carolina (2396)
- University of Texas at El Paso (2169)
- Marquette University (2104)
- Chinese Chemical Society | Xiamen University (2032)
- University of New Mexico (1931)
- Washington University in St. Louis (1830)
- Keyword
-
- Engineering (2860)
- Machine learning (1463)
- Optimization (1222)
- Simulation (1174)
- Applied sciences (1099)
-
- Construction (903)
- Sustainability (878)
- Design (874)
- Machine Learning (843)
- Deep learning (819)
- Modeling (751)
- Additive manufacturing (581)
- Concrete (552)
- Safety (538)
- Computer Science (535)
- Architecture (525)
- Artificial intelligence (514)
- Building (499)
- Nanoparticles (481)
- Robotics (477)
- Education (466)
- CFD (453)
- Energy (446)
- UAV (444)
- Corrosion (443)
- Engineering education (426)
- Conference (411)
- ASME (401)
- Proceedings (401)
- Mechanical Engineering (391)
- Publication Year
-
- 2026 (6057)
- 2025 (8720)
- 2024 (9316)
- 2023 (9824)
- 2022 (9389)
-
- 2021 (10037)
- 2020 (10652)
- 2019 (10511)
- 2018 (8954)
- 2017 (8354)
- 2016 (9651)
- 2015 (7571)
- 2014 (7308)
- 2013 (7338)
- 2012 (6360)
- 2011 (5881)
- 2010 (5435)
- 2009 (4177)
- 2008 (4201)
- 2007 (3837)
- 2006 (3384)
- 2005 (3061)
- 2004 (2777)
- 2003 (2065)
- 2002 (1792)
- 2001 (1774)
- 1999 (1304)
- 1998 (1355)
- 1993 (1342)
- 1991 (1362)
- Publication
-
- Theses and Dissertations (11563)
- Electronic Theses and Dissertations (4149)
- Masters Theses (3933)
- Journal of System Simulation (3924)
- Theses (3520)
-
- Electrical and Computer Engineering Faculty Research & Creative Works (3455)
- Nebraska Tractor Tests (3402)
- Faculty Publications (3290)
- Turkish Journal of Electrical Engineering and Computer Sciences (3106)
- Chulalongkorn University Theses and Dissertations (Chula ETD) (2554)
- International Conference on Case Histories in Geotechnical Engineering (2055)
- Journal of Electrochemistry (2032)
- Master's Theses (2029)
- Dissertations (1901)
- Kentucky Transportation Center Research Report (1824)
- Coal Geology & Exploration (1822)
- Doctoral Dissertations (1811)
- International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics (1566)
- USF Tampa Graduate Theses and Dissertations (1499)
- Articles (1408)
- Browse all Theses and Dissertations (1369)
- Open Access Theses & Dissertations (1323)
- Computer Science & Engineering Syllabi (1312)
- LSU Master's Theses (1312)
- Journal of Marine Science and Technology–Taiwan (1299)
- Mechanical and Aerospace Engineering Faculty Research & Creative Works (1278)
- Civil, Architectural and Environmental Engineering Faculty Research & Creative Works (1267)
- Publications (1260)
- All Theses (1247)
- Graduate Theses and Dissertations (1238)
- Publication Type
Articles 174451 - 174480 of 198026
Full-Text Articles in Engineering
Nebraska Summary: S253 New Holland 8560, Nebraska Tractor Test Lab
Nebraska Summary: S253 New Holland 8560, Nebraska Tractor Test Lab
Nebraska Tractor Tests
ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …
Nebraska Summary: S251 New Holland 8360, Nebraska Tractor Test Lab
Nebraska Summary: S251 New Holland 8360, Nebraska Tractor Test Lab
Nebraska Tractor Tests
ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …
Nebraska Summary: S246 New Holland 6635, Nebraska Tractor Test Lab
Nebraska Summary: S246 New Holland 6635, Nebraska Tractor Test Lab
Nebraska Tractor Tests
ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …
Nebraska Summary: S245 New Holland 5635, Nebraska Tractor Test Lab
Nebraska Summary: S245 New Holland 5635, Nebraska Tractor Test Lab
Nebraska Tractor Tests
ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …
Nebraska Summary: S259 Case-Ih Mx 135, Nebraska Tractor Test Lab
Nebraska Summary: S259 Case-Ih Mx 135, Nebraska Tractor Test Lab
Nebraska Tractor Tests
ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …
Nebraska Summary: S284 New Holland 9882, Nebraska Tractor Test Lab
Nebraska Summary: S284 New Holland 9882, Nebraska Tractor Test Lab
Nebraska Tractor Tests
ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …
Effect Of Pt Doping On Nucleation And Crystallization In Li2o · 2sio2 Glass: Experimental Measurements And Computer Modeling, K. Lakshmi Narayan, K. F. Kelton, C. S. Ray
Effect Of Pt Doping On Nucleation And Crystallization In Li2o · 2sio2 Glass: Experimental Measurements And Computer Modeling, K. Lakshmi Narayan, K. F. Kelton, C. S. Ray
Materials Science and Engineering Faculty Research & Creative Works
Heterogeneous nucleation and its effects on the crystallization of lithium disilicate glass containing small amounts of Pt are investigated. Measurements of the nucleation frequencies and induction times with and without Pt are shown to be consistent with predictions based on the classical nucleation theory. A realistic computer model for the transformation is presented. Computed differential thermal analysis data (such as crystallization rates as a function of time and temperature) are shown to be in good agreement with experimental results. This modeling provides a new, more quantitative method for analyzing calorimetric data.
Plastic Fiber Rolling For Concrete Reinforcement, Jeffery S. Thomas
Plastic Fiber Rolling For Concrete Reinforcement, Jeffery S. Thomas
Masters Theses
"Fiber reinforced concrete is gaining in acceptance and usage as its strength and toughness benefits are realized. Polypropylene fibers are currently the most commonly used fibers. However, the cost of virgin plastics limits the percent content that can be economically added to concrete. One would first believe that recycled plastics could offer a viable alternative to virgin-plastic fibers, but at present time extra selection and cleaning steps required to reprocess the recycled plastic into fibers makes it more expensive than virgin-plastic fibers. A fiber rolling process conceived and developed at the University of Missouri-Rolla has the potential of making recycled …
An Approach To Just-In-Time Implementation In Discrete Parts Manufacturing, Phillip Gregory Shirey
An Approach To Just-In-Time Implementation In Discrete Parts Manufacturing, Phillip Gregory Shirey
Masters Theses
"Just-In-Time manufacturing is a philosophy that encourages waste reduction and the elimination of non-value-added activities. The processes affected include office and shop personnel. When successfully implemented, JIT accounts for improved production lead time cycles, reduced inventories, improved employee morale, reduced cost of goods, and continuous improvements of the total business process.
This thesis identifies real world problems many medium size U.S. manufacturing companies now face, and an approach to JIT implementation in discrete parts manufacturing. The approach includes developing strategies to motivate the employees and to implement the tools and techniques of JIT, Total Quality Management, ISO 9001, and MRP …
Computing Optimal Cocomo Effort Multiplier Values And Optimal Casebase Subsets Using Monte Carlo Methods, Robert Joseph Maidhof
Computing Optimal Cocomo Effort Multiplier Values And Optimal Casebase Subsets Using Monte Carlo Methods, Robert Joseph Maidhof
Retrospective Theses and Dissertations
There have been many studies performed and techniques applied to solve the problem of estimating man-month effort for software projects. Despite all the effort expended to solving this problem the results achieved from the various techniques have not been embraced by the software community as very reliable or accurate. This thesis uses Monte Carlo methods to obtain optimal values for COCOMO effort multipliers which minimize the average of the absolute values of the relative errors (AARE) of man-month estimate for two industry supplied casebases. For example, when using three COCOMO cost drivers (complexity, language experience, application experience) and the COCOMO …
Vegetative Filter Strip Design For Grassed Areas Treated With Animal Manures, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr.
Vegetative Filter Strip Design For Grassed Areas Treated With Animal Manures, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr.
Biosystems and Agricultural Engineering Faculty Publications
Vegetative filter strips (VFS) are a low-cost management option that have been demonstrated to be effective in reducing runoff transport of fertilizer constituents applied to grassed areas (pasture or meadow). Runoff quality studies involving fertilizers applied to grassed areas suggest that VFS can be designed by assuming that (1) only infiltration is responsible for pollutant removal, (2) the first post-application runoff event is most important from a water quality perspective (enabling a design event approach), and (3) no pollutant build-up that degrades VFS performance will occur. The purpose of this study was to develop a VFS design algorithm for grassed …
A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards
A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards
Biosystems and Agricultural Engineering Faculty Publications
Accurately predicting the rainfall-runoff process is of vital importance for water quality models as well as for correct design of various types of hydraulic structures. This article presents a method of describing the cumulative infiltration process as an explicit function of time using an approximation to the modified Green-Ampt equation given by Mein and Larson (1971). The resulting equation is helpful in predicting cumulative infiltration and therefore infiltration capacity for computer simulation models. The proposed method takes about 50% less time than the usual iterative technique for the same degree of accuracy. The maximum error due to approximation was 1% …
Simulation Of Runoff Transport Of Animal Manure Constituents, Yang Wang, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott
Simulation Of Runoff Transport Of Animal Manure Constituents, Yang Wang, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott
Biosystems and Agricultural Engineering Faculty Publications
Runoff losses of land-applied animal manure constituents can adversely affect the quality of downstream waters. Reliable mathematical simulation models can help estimate runoff losses of animal manure constituents and identify management measures to reduce these losses. The objective of this study was to develop and calibrate an event-based simulation model to describe the runoff transport of solids (soil and manure particles) and nutrients (nitrogen and phosphorus) from areas treated with animal manure. The resulting model, consisting of linked hydrology, soil/manure transport, and nutrient transport components, is process-oriented and uses measurable parameters to the greatest degree possible. The three components of …
Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr.
Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr.
Biosystems and Agricultural Engineering Faculty Publications
Long-term land application of animal manures, even at agronomic rates, can promote accumulation of soil phosphorus (P) which can, in turn, contribute to increased P loadings to downstream waters. The objective of this study was to assess the soil and runoff effects of replacing animal manure as a soil amendment with inorganic fertilizer (ammonium nitrate, NH4NO3) on fields that had been treated previously with animal manures. Runoff from two pairs of small fields (0.57 to 1.46 ha) was sampled from September 1991 to April 1994. All fields had been treated previously with animal manures; after runoff …
Poultry Litter-Treated Length Effects On Quality Of Runoff From Fescue Plots, Dwayne R. Edwards, Philip A. Moore Jr., Tommy C. Daniel, Puneet Srivastava
Poultry Litter-Treated Length Effects On Quality Of Runoff From Fescue Plots, Dwayne R. Edwards, Philip A. Moore Jr., Tommy C. Daniel, Puneet Srivastava
Biosystems and Agricultural Engineering Faculty Publications
Using experimental data and/or mathematical simulation models to identify practices that reduce pollution from manure-treated areas is sometimes perceived as limited by the unknown validity of extrapolating plot-scale data to larger areas and by uncertainties in modeling transport of various pollutants. The objectives of this study were to assess the effect of length of manure treatment on runoff concentrations of poultry litter constituents and to define the modes of transport (particulate versus soluble) for nitrogen (N), phosphorus (P), carbon (C), and solids. Poultry litter was applied to three 1.5- x 18.3-m fescue (Festuca arundinacea Schreb.) plots with runoff collection …
Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr.
Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr.
Biosystems and Agricultural Engineering Faculty Publications
Runoff transport of phosphorus (P) is often predicted from simple equations with parameters determined from data applicable primarily to row-cropped and fallow cover conditions. The applicability, accuracy, and precision of such P transport prediction equations under pasture situations are less well defined. The objectives of this study were to determine parameters of simplified runoff P transport equations for pasture fields and to assess the accuracy and precision of the equations. Runoff, sediment yield, soluble P transport, and particulate P transport data were collected from four pasture fields in northwestern Arkansas. Runoff event enrichment ratios and extraction coefficients were computed, and …
Development Of A Biologically Based Aerobic Composting Simulation Model, Dennis P. Stombaugh, Sue E. Nokes
Development Of A Biologically Based Aerobic Composting Simulation Model, Dennis P. Stombaugh, Sue E. Nokes
Biosystems and Agricultural Engineering Faculty Publications
A relatively simple dynamic model based on microbial process kinetics has been developed for aerobic composting. Differential equations describing microbial, substrate, and oxygen concentrations, as well as moisture and temperature profiles have been derived as a function of vessel size and aeration rate. Microbial biomass growth was described using Monod growth kinetics as a function of degradable substrate concentration, oxygen concentration, moisture content, and compost temperature. Facility and fan operating costs have been included to permit economic optimization of the process. Predicted results demonstrated the ability of the model to quantify and describe the influence of multiple interacting factors (temperature, …
System Identification Methods For Dynamic Testing Of Fluid-Film Bearings, Jerzy T. Sawicki, M. L. Adams, R. J. Capaldi
System Identification Methods For Dynamic Testing Of Fluid-Film Bearings, Jerzy T. Sawicki, M. L. Adams, R. J. Capaldi
Mechanical Engineering Faculty Publications
There are various system identification approaches typically used to extract the rotordynamic coefficients from simultaneously measured dynamic force and motion signals. Since the coefficient values extracted can vary significantly as a function of the system identification approach used, more attention is needed to treat this issue than is typically included in the rotor dynamics literature. This paper describes system identification and data reduction methods used for extracting rotordynamic coefficients of fluid-film journal bearings. Data is used from a test apparatus incorporating a double-spoolshaft spindle which permits independent control over the journal spin speed and the frequency of an adjustable-magnitude circular …
The Effects Of Post Inoculant Additions On Ductile Iron Fade, Travis James Frush
The Effects Of Post Inoculant Additions On Ductile Iron Fade, Travis James Frush
Dissertations and Theses @ UNI
This study involved the investigation of three specific, commercially available, post inoculants for ductile iron and their effect on the magnesium fading rate and chill reducing tendency in a low volume production environment. Although fading effects of ductile iron have been extensively investigated, in general, they apply to high volume production operations. Unfortunately, for the smaller foundry operations, many of the process solutions proposed for the prevention of the fading effects are not applicable or practical. In addition to the small production operations, new process technologies are also excluded from many of these process solutions. For this reason, a study …
Effects Of Refrigeration And Cryogenic Treatments On Austempered Ductile Iron, Gerard R. Thiel
Effects Of Refrigeration And Cryogenic Treatments On Austempered Ductile Iron, Gerard R. Thiel
Dissertations and Theses @ UNI
Low temperature treatment, as a method of improving mechanical properties of metals, has been studied and used for well over 60 years. Until recently these treatments have been limited to hardness and wear improvements of high alloy irons and steels. The purpose of this research is to determine the effects of refrigeration and cryogenic treatments on the mechanical properties, including hardness and tensile strength of austempered ductile iron.
This research included the production of a high strength ductile iron of low alloy content capable of being used in either the as cast, conventionally heat treated or austempered condition. Refrigeration and …
Ultrasound Modified Ferric Hydroxide/Cupric Ion Adsorption And Sequestration At Varying Ph Levels, Humberto Campos
Ultrasound Modified Ferric Hydroxide/Cupric Ion Adsorption And Sequestration At Varying Ph Levels, Humberto Campos
Dissertations and Theses @ UNI
This study was undertaken to determine if hydrous metal oxide adsorption, an important treatment method used to remove adsorbates from aqueous solution, could be enhanced through ultrasonic irradiation. A model system based on preformed hydrous ferric oxide as the adsorbent and copper as the adsorbate was investigated. Brief exposure of the preformed hydrous ferric oxide floe to intense ultrasonic radiation (ca. 13 Watts/cm2 ) in the presence of copper species effectively disrupted the flocculated particles permitting the copper adsorbate to access adsorption sites previously isolated within the floe. The experimental data indicate that ultrasonic disruption of pre-formed hydrous ferric oxide …
Method And Apparatus For Applying Herbicides, Marian Mazurkiewicz
Method And Apparatus For Applying Herbicides, Marian Mazurkiewicz
Mining Engineering Faculty Research & Creative Works
A method of applying herbicide to plants involves delivering a liquid herbicide solution to the plant foliage in a high pressure jet of sufficient energy to physically disrupt the surface of the foliage. The high pressure jet can be either a coherent jet or it can be a stream of droplets. The coherent stream can have sufficient energy to cut the foliage, creating new surfaces that are more wettable by the herbicide solution, and more susceptible to penetration by the herbicide in the solution. The droplets in the droplet stream can be made to be of sufficient size and energy …
Asynchronous Multiuser Decorrelating Detector For Awgn Channel, Ashwini A. Borkar
Asynchronous Multiuser Decorrelating Detector For Awgn Channel, Ashwini A. Borkar
Theses
Decorrelating detector is one of the sub-optimum detectors for CDMA applications that generally has better performance than the conventional detector and is near-far resistant. Synchronous decorrelating detector employing DPSK modulation is considered and its simulation results are presented.
Attention is focussed on one-shot decorrelating detector for a two user case for asynchronous transmission, where each symbol interval is considered seperately. Initially the performance of the detector with exact estimation of the relative delay is analyzed and then the effect of inaccurate estimation on the probability of error is discussed.
Terminal Sliding Mode Control For Rigid Robotic Manipulators With Uncertain Dynamics, Nicola Ritter
Terminal Sliding Mode Control For Rigid Robotic Manipulators With Uncertain Dynamics, Nicola Ritter
Theses: Doctorates and Masters
This thesis presents two new adaptive control laws that use the terminal sliding mode technique for the tracking problem of rigid robotic manipulators with non-linearities, dynamic couplings and uncertain parameters. The first law provides a robust scheme which uses several properties of rigid robotic mauipulators and adaptively adjusts seven uncertain parameter bounds. The law ensures finite time error convergence to the system origin and is simple to implement The second law treats the manipulator as a partially known system. The known dynamics are used to build a nominal control law and the effects of unknown system dynamics arc compensated for …
The Mobile Telephone: The Transportation Of Social Relationships, Kenneth C. Staples
The Mobile Telephone: The Transportation Of Social Relationships, Kenneth C. Staples
Theses: Doctorates and Masters
In the studies of contemporary electronic media artifacts and their effects on society, television, satellites, and computers have been extensively investigated and their various impacts well documented. With regards to telecommunication technologies, academic scholarship is somewhat less, with most comment being restricted to either historic evolution, or technical description. Exceptions to this are, Marvin's reference to the telephone in her publication, When Old Technologies Were New: Thinking About Electronic Communication in the Late Nineteenth Century (1988}, and Umble's The Amish and the telephone: resistance and reconstruction (1992). Both of these publications are used for supporting arguments in my thesis investigating …
Optimization For Maximum Performance High-Speed Engines, David W. Riggins
Optimization For Maximum Performance High-Speed Engines, David W. Riggins
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Fuel-air combustion and the generation of irreversibility in high-speed flows are described in terms of the fundamental principles of nonequilibrium, work availability, and entropy increases. Engine thrust is analytically related to the overall engine irreversibility and the degree of combustion: Issues involving mixing enhancement assessment and engine optimization are then formalized and clarified. The concept of thrust-potential, as used in engine design and optimization, is shown to be a consistent application of the principles and findings of this and related investigations. This work was supported through NASA Grant NAG 1-1189. Special thanks are due to Charles McClinton at NASA Langley …
Hamiltonian Based Adaptive Critics For Missile Guidance, S. N. Balakrishnan, Jie Shen
Hamiltonian Based Adaptive Critics For Missile Guidance, S. N. Balakrishnan, Jie Shen
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A Hamiltonian based adaptive critic structure is proposed for solving missile guidance problems. This structure consists of a supervisor neural network called 'critic' and a controller network called 'action'. Together they are used to solve model-based guidance problems. The advantage of this approach is that: i) the training data for each network is created by the other network, ii) the converged solutions yield near optimal guidance over the entire span of the training range, and iii) they can be used as feedback controllers though trained off-line. A main contribution is that we establish a direct link between traditional optimal control …
Heat Transfer In Two-Phase Solid-Rocket Plumes, Harlan F. Nelson, John C. Fields
Heat Transfer In Two-Phase Solid-Rocket Plumes, Harlan F. Nelson, John C. Fields
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Results of a direct simulation Monte Carlo (DSMC) and free molecule (FM) analysis of convective heat transfer to Al2O3 particles in solid-rocket plume environments are presented. The particle diameters are assumed to be 4μm, and the plume gases are CO2, H2O, CO, and N2. The plume gas temperature is 2000 K. Particle temperatures of 1500, 2000, and 2500 K are investigated for Knudsen numbers from 1/2 to 1000 (from slip flow to FM flow). The Nusselt number is presented in terms of Knudsen number and Reynolds number (or relative velocity). Both the Kavanau and the Kashmarov and Svirshevskii correlations generally …
Global Characteristics And Structure Of Hydrogen-Air Counterflow Diffusion Flames, J. Zhao, Kakkattukuzhy M. Isaac, G. L. Pellett
Global Characteristics And Structure Of Hydrogen-Air Counterflow Diffusion Flames, J. Zhao, Kakkattukuzhy M. Isaac, G. L. Pellett
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A model based on similarity transformation, for the nitrogen-diluted, H2-air opposed-jet laminar counterflow diffusion flame (CFDF), was developed independently of earlier models, and numerically solved to study flame location and flame structure and extinction limits. Numerical stiffness is handled by a special treatment of the species production term. Flame location with respect to the stagnation plane is identified as an important parameter that governs H2-air diffusion flames, and physical explanations are given to show how flame location is affected by fuel dilution, strain rate, and Lewis number. Results show very good agreement with experimental extinction conditions. The effect of thermal …
Analysis Of A Single-Phase Induction Machine With A Shifted Auxiliary Winding, T. A. Walls, Scott D. Sudhoff
Analysis Of A Single-Phase Induction Machine With A Shifted Auxiliary Winding, T. A. Walls, Scott D. Sudhoff
Electrical and Computer Engineering Faculty Research & Creative Works
This paper extents the method of multiple reference frames to the analysis of asymmetrical induction motors with non-orthogonal stator windings, with particular emphasis on the permanent split capacitor (PSC) machine. The predictions of the method are verified by comparison to both experimental results and to results obtained using a machine variable computer simulation. Once verified, the method is used to derive the transfer function relating rotor speed to load torque disturbance, which is of particular interest when analyzing PSC machines driving compressor loads. It is shown that the transfer function exhibits a distinct resonant point, and that the magnitude of …