Analyse Du Comportement Réel Et De L'Optimisation Structurelle Des Cycles De Turbines À Gaz,
2011
Université Politehnica de Bucarest
Analyse Du Comportement Réel Et De L'Optimisation Structurelle Des Cycles De Turbines À Gaz, Alexandru Dobrovicescu, Michel Feidt, Lavinia Grosu, Jim Mcgovern, Georgiana Tirca-Dragomirescu
Conference Papers
L’article présente une étude comparative, basée sur l’analyse exégétique, de l’effet de non prise en considération du comportement réel de l’agent thermique et de l’utilisation des modèles simplifiés pour calculer les performances des cycles de turbines à gaz avec et sans récupération de chaleur. Un intérêt spécial a été réservé au processus de combustion et au transfert de chaleur dans le préchauffeur d’air. La variation des destructions et des pertes d’exergie par rapport à la variation des paramètres fonctionnels est présentée.
Gimbaled Permanent Magnet-Based Attitude Control For Pico/Nano-Satellites,
2011
University of Arkansas, Fayetteville
Gimbaled Permanent Magnet-Based Attitude Control For Pico/Nano-Satellites, Rex Bair
Mechanical Engineering Undergraduate Honors Theses
As man-made satellites grow continually smaller and smaller, new, lower mass, volume, and power solutions must be devised to give these satellites the same performance capabilities as larger satellites. One subsystem that is especially difficult to shrink is the Attitude Determination and Control System (ADACS), which is used to position the satellite in a given orientation with respect to a specific reference frame. This paper explores a novel mechanism which combines both of these functions into one device. A permanent magnet is used in conjunction with the geomagnetic reference frame to provide magnetic torque to change the spacecraft's attitude. By …
Carbon Nanotube Based Ion Sensitive Field Effect Transistor,
2011
University of Arkansas, Fayetteville
Carbon Nanotube Based Ion Sensitive Field Effect Transistor, Matthew Margis
Mechanical Engineering Undergraduate Honors Theses
Carbon nanotubes (CNTs) have been the subject of much research in the past two decades. Due to their extraordinary mechanical and electrical properties, CNTs are ideal candidates for various sensors and electronic device applications. The purpose of this research is to overcome the difficulties in separating and aligning CNTs so that they can be implemented in an ion sensitive field effect transistor (ISFET). A solution to the alignment process has been presented that involves cutting nano channels on a microelectrode chip with an Atomic Force Microscope (AFM) in order to nanomanipulate the CNTs into the nano channels. Upon successfully cutting …
Spectral Characterization Of Venusian Surface Mineralogy,
2011
University of Arkansas, Fayetteville
Spectral Characterization Of Venusian Surface Mineralogy, Johnathon Conley
Mechanical Engineering Undergraduate Honors Theses
While the atmospheric chemical composition of the Venusian atmosphere has been characterized at length by probes and ground-based equipment, the surface mineralogy of Venus is not yet well understood. The extremely thick atmosphere of Venus shields the surface from direct observation. While radar imaging of the surface reveals surface morphology, surface composition is difficult to characterize at a distance. Observation is also difficult due to the intense temperature (approximately 480°C) and pressure (approximately 90 atm) found on the surface. This has prompted NASA and other institutions around the world to begin planning for new missions to land on the surface …
Airplane Landing Flare-The Last 5 Seconds,
2011
Minnesota State University, Mankato
Airplane Landing Flare-The Last 5 Seconds, Nihad E. Daidzic
Aviation Department Publications
No abstract provided.
Effect Of Heavy Metals Found In Flue Gas On Growth And Lipid Accumulation For Green Algae Scenedesmus Obliquus,
2011
Utah State University
Effect Of Heavy Metals Found In Flue Gas On Growth And Lipid Accumulation For Green Algae Scenedesmus Obliquus, Reece Butler
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
In recent years there has been a growing interest within the United States to replace fossil fuels with biofuels for environmental and national security reasons. Algal feedstocks have the potential of producing significantly higher yields of oil for biofuels than any other source. It is well known that high concentrations of CO2 can increase algal yields. Flue gas from coal fire power plants is an obvious source of CO2. The flue gas, however, will contain other chemicals besides CO2 that may not be beneficial to the algae. The research objectives for this study were to determine …
Lower Extremity Biomechanics During Weightlifting Exercise Vary Across Joint And Load,
2011
University of Michigan
Lower Extremity Biomechanics During Weightlifting Exercise Vary Across Joint And Load, Kristof Kipp, Chad Harris, Michelle B. Sabick
Mechanical and Biomedical Engineering Faculty Publications and Presentations
The purpose of this study was to determine the effect of load on lower extremity biomechanics during the pull-phase of the clean. Kinematic and kinetic data of the three joints of the lower extremity were collected while participants performed multiple sets of cleans at three percentages: 65, 75, and 85% of 1-Reptition maximum (RM). General linear models with repeated measures were used to assess the influence of load on angular velocities, net torques, powers, and rates of torque development at the ankle, knee, and hip joint. The results suggest that the biomechanical demands required from the lower extremities change with …
Simulation And Validation Of Two-Component Flow In A Void Recirculation System,
2011
California Polytechnic State University, San Luis Obispo
Simulation And Validation Of Two-Component Flow In A Void Recirculation System, Oscar Eduardo Daza
Master's Theses
Nuclear power plants rely on the Emergency Core Cooling System (ECCS) to cool down the reactor core in case of an accident. Occasionally, air is entrained into the suction piping of ECCS causing voids that decrease pumping efficiency, and consequently damage the pumps. In an attempt to minimize the amount of voids entering the suction side of the pump in ECCS, a Void Recirculation System (VRS) experiment was conducted for a proof of concept purpose. While many studies have been oriented in studying two-component flow behavior in ECCS, none of them propose a solution to minimize air entrainment. As a …
Characterization Of Fracture Toughness G (Sub C) Of Pvc And Pes Foams,
2011
Florida Atlantic University
Characterization Of Fracture Toughness G (Sub C) Of Pvc And Pes Foams, Elio E. Saenz, Leif A. Carlsson, Anette M. Karlsson
Mechanical Engineering Faculty Publications
The fracture behavior of polyvinyl chloride (PVC) and polyethersulfone (PES) foams has been examined using the single-edge notch bend and the double cantilever beam (DCB) tests. PVC foam densities ranging from 45 to 100 kg/m3 and PES foam densities ranging from 60 to 130 kg/m3 were examined. The PVC foams failed in a linear elastic brittle manner, whereas the PES foams displayed much more ductility and substantially larger toughness at a comparable foam density. The cell wall thickness of the PES foams was almost twice the thickness of the PVC foams which may have contributed to the high …
The Effect Of Axial Conduction On Heat Transfer In A Liquid Microchannel Flow,
2011
University of Nebraska-Lincoln
The Effect Of Axial Conduction On Heat Transfer In A Liquid Microchannel Flow, Kevin D. Cole, Barbaros Çetin
Department of Mechanical and Materials Engineering: Faculty Publications
Analysis is presented for conjugate heat transfer in a parallel-plate microchannel. Axial conduction in the fluid and in the adjacent wall are included. The fluid is a constant property liquid with a fully-developed velocity distribution. The microchannel is heated by a uniform heat flux applied to the outside of the channel wall. The analytic solution is given in the form of integrals by the method of Green’s functions. Quadrature is used to obtain numerical results for the local and average Nusselt number for various flow velocities, heating lengths, wall thicknesses, and wall conductivities. These results have application in the optimal …
Ultrasonic Methods For The Characterization Of Complex Materials And Material Systems: Polymers, Structured Polymers, Soft Tissue And Bone,
2011
University of Nebraska-Lincoln
Ultrasonic Methods For The Characterization Of Complex Materials And Material Systems: Polymers, Structured Polymers, Soft Tissue And Bone, Charles Landais
Department of Engineering Mechanics: Dissertations, Theses, and Student Research
Understanding the characteristics and structure of materials is of importance in proper modeling and effective design of many products. Complex materials such as polymers, structured material systems, or biological materials provide a particular challenge to many of the traditional methods for doing this. In this dissertation I study the use of ultrasonic wave techniques to characterize several complex materials. These include plastically deformed and aged polycarbonate (PC), a structured PC plate with water filled cavities, bovine bone, and an elastomer used as a skin simulant. In each case, this work was part of a larger project that studied different aspects …
Parametric Amplification In The Context Of Vibratory Energy Harvesting,
2011
Clemson University
Parametric Amplification In The Context Of Vibratory Energy Harvesting, Roger Bode
All Theses
Using a vibratory energy harvester (VEH) to independently power a sensor has become an increasingly popular topic due to the small amount of power current sensors require to operate. This can be achieved by scavenging energy from the ambient environment where the sensor is located. Numerous linear and nonlinear energy harvesters have been proposed in order to deal with various vibratory environments, along with improving the power production and/or bandwidth of the device.
In this thesis, we propose a technique to harvest energy from excitation sources that possess two frequency components: a fundamental component with large energy content, and a …
Requirements Determination Of A Novel Non-Pneumatic Wheel Shear Beam For Low Rolling Resistance,
2011
Clemson University
Requirements Determination Of A Novel Non-Pneumatic Wheel Shear Beam For Low Rolling Resistance, Niranjan Thyagaraja
All Theses
The hysteretic loss associated with cyclic shear in the elastomeric shear layer is one of the prevailing concerns for the development of a low rolling loss non-pneumatic wheel. We propose to eliminate the hysteretic losses associated with the elastomeric shear layer and thus, reduce the corresponding rolling resistance by using linear elastic materials which are inherently non-hysteretic. Since the shear modulus of a viscoelastic shear layer is less than that of an elastic material by several orders of magnitude, the challenge to achieve a low effective shear modulus shear layer with linear elastic materials directs towards the development of a …
Joule Heating Effects On Electrokinetic Transport In Constriction Microchannels,
2011
Clemson University
Joule Heating Effects On Electrokinetic Transport In Constriction Microchannels, Sriram Sridharan
All Theses
Microfluidic technology involving multidisciplinary studies including MEMS, chemistry, physics, fluids and heat transfer has been developed into a promising research field in the recent decade. If offers many advantages over conventional laboratory techniques like reduced reagent consumption, faster analysis, easy fabrication and low chemical waste. Microfluidic lab-on-a-chip devices have been used to manipulate cells and particles like sorting, separating, trapping, mixing and lysing. Microfluidic manipulation can be achieved through many methods and insulator based dielectrophoresis (iDEP) is one of the highly used method in the recent years. In iDEP, both DC and AC voltages can be applied to the remote …
Finite Element Analysis Prediction Of Stresses In H.L. Hunley Submarine By Global-To-Local Model Coordination,
2011
Clemson University
Finite Element Analysis Prediction Of Stresses In H.L. Hunley Submarine By Global-To-Local Model Coordination, Aditya Sai Nag Choragudi
All Theses
H.L Hunley was a submarine of the Confederate States of America that participated in the American Civil War. On February 17, 1864, H.L.Hunley created history by becoming the first submarine to sink a enemy ship after its attack on USS Houstanic. After Hunley never returned to the shore and the details of its wreck were unknown. On August 8, 2000, H. L Hunley was brought to the surface after 136 years of its wreckage. The submarine is currently at the Warren Lasch Conservation Center located in Charleston.
This study focuses on the structural analysis of the H.L Hunley submarine to …
Evaluation Of Biomass And Coal Briquettes For A Spreader Stoker Boiler Using An Experimental Furnace - Modeling And Test,
2011
Clemson University
Evaluation Of Biomass And Coal Briquettes For A Spreader Stoker Boiler Using An Experimental Furnace - Modeling And Test, Gavin Wiggins
All Theses
The compliance of coal-fired boilers with emissions regulations is a concern for many facilities. The introduction of biomass briquettes in industrial boilers can help to reduce greenhouse gas emissions and coal usage. In this research project, a thermodynamic chemical equilibrium model was derived and analytical simulations performed for a coal boiler system for several types of biomass fuels such as beech, hickory, maple, poplar, white oak, willow, sawdust, torrefied willow, and switchgrass. The biomass emissions were compared to coal and charcoal emissions. The chemical equilibrium analysis numerically estimated the emissions of CO, CO2, NO, NO2, N2O, SO2, and SO3. When …
Connective Complexity Methods For Analysis And Prediction In Engineering Design,
2011
Clemson University
Connective Complexity Methods For Analysis And Prediction In Engineering Design, James Mathieson
All Theses
Complexity is an aspect of engineering design that is often addressed directly with the principle that 'designs should be simple'. However, such a principle fails to offer an effective means of quantifying the complexity of a given design for comparison and decision making. The measurement of complexity within a specific representations and domains has been well established. However, such measurements are inherently limited in their applicability and not always clear in their implications. This research presents a method of measuring complexity from different engineering representations in a consistent manner and explores the application of these measures.
The development of a …
Multi-Scale Modeling Of The Fontan Circulation Using A Mock Circulatory System,
2011
Clemson University
Multi-Scale Modeling Of The Fontan Circulation Using A Mock Circulatory System, John Chiulli
All Theses
The Fontan circulation is the result of a series of operations performed to save the lives of children born with univentricular circulations. The Fontan procedure achieves venous return to the pulmonary circulation without a ventricular power source. The load on the heart is reduced to normal, and these patients can lead a normal life into adulthood, although late complications continue to prevent normal lifespan. A unique feature of the Fontan circulation is the dependency of inferior vena cava flow on respiration. The Fontan circulation has been modeled experimentally using an adjustable mock circulatory system, which for the first time includes …
An Experimental And Numerical Study Of Secondary Flows And Film Cooling Effectiveness In A Transonic Cascade,
2011
University of Central Florida
An Experimental And Numerical Study Of Secondary Flows And Film Cooling Effectiveness In A Transonic Cascade, James C. Kullberg
HIM 1990-2015
Experimental tests on a transonic annular rig are time-consuming and expensive, so it is desirable to use experimental results to validate a computational model which can then be used to extract much more information. The purpose of this work is to create a numerical model that can be used to simulate many different scenarios and then to apply these results to experimental data.; In the modern world, gas turbines are widely used in aircraft propulsion and electricity generation. These applications represent a massive use of energy worldwide, so even a very small increase in efficiency would have a significant beneficial …
Synthesis And Characterization Of Poly(Butylene Oxide) Grafted Carbon Nanofibers,
2011
The University of Texas Rio Grande Valley
Synthesis And Characterization Of Poly(Butylene Oxide) Grafted Carbon Nanofibers, Carlos Ramos, Ram Thapa, Karen Lozano, Mircea Chipara, Domingo Ferrer, Jose J. Gutierrez
Mechanical Engineering Faculty Publications
The grafting of polybutylene oxide onto purified and functionalized carbon nanofibers is reported. Grafting was possible after the insertion of 2-(formyloxy)ethyl 2-bromo-2-methylpropanoate onto the carbon nanofibers. The polymerization of tetrahydrofuran was mediated by copper(I) bromide and 1,1,4,7-pentamethyl diethylenetriamine. The polymer-grafted carbon nanofibers were characterized by Raman spectrsocopy, Transmission Electron Microscopy, and Thermogravimetric Analysis. TEM images of CNF-COOH (A), CNF-PBO (B), completely open tip of CNF-COOH, and coated tip of CNF-PBO (D) are shown in the left panel. The right panel depicts the distribution of bromine (blue), and carbon (red) atoms inside and in the vicinity of CNF-Br (as obtained by …
