Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2009

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 151 - 180 of 596

Full-Text Articles in Mechanical Engineering

Assessing Plastically Dissipated Energy As A Condition For Fatigue Crack Growth, D. Cojocaru, Anette M. Karlsson Jul 2009

Assessing Plastically Dissipated Energy As A Condition For Fatigue Crack Growth, D. Cojocaru, Anette M. Karlsson

Mechanical Engineering Faculty Publications

The suitability of using a proposed condition for simulating cyclic crack propagation in a numerical scheme is qualitatively investigated, employing the finite element method. The propagation criterion is based on a condition that relates the plastically dissipated energy to a critical value. In the finite element simulation scheme, the crack is allowed to propagate when the criterion is satisfied, and the crack propagates until the condition is no longer fulfilled. Experimentally, it is well established that a negative load ratio increases the crack propagation rate, whereas a tensile overload tends to decrease the crack propagation rate. By simulating these load …

Go to article

Towards The Efficient Probabilistic Characterization Of Tropical Cyclone-Generated Storm Surge Hazards Under Stationary And Nonstationary Conditions, Senanu Kudjo Agbley Jul 2009

Towards The Efficient Probabilistic Characterization Of Tropical Cyclone-Generated Storm Surge Hazards Under Stationary And Nonstationary Conditions, Senanu Kudjo Agbley

Civil & Environmental Engineering Theses & Dissertations

The scarcity of observations at any single location confounds the probabilistic characterization of tropical cyclone-generated storm surge hazards using annual maxima and peaks-over-threshold methods. The EST and the JPM are indirect approaches aimed at estimating the probability distribution of the response variable of interest (i.e. storm surge) using the probability distributions of predictor variables (e.g. storm size, storm intensity etc.). In the first part of this work, the relative performance of the empirical simulation technique (EST; Borgman et al., 1992) and the joint probability method (JPM; Myers, 1970) is evaluated via stochastic simulation methods. It is shown that the JPM …

Go to article

A Three Dimensional Numerical Investigation Of A Donor Material In Friction Stir Welding, Justin M. Rice Jul 2009

A Three Dimensional Numerical Investigation Of A Donor Material In Friction Stir Welding, Justin M. Rice

Mechanical & Aerospace Engineering Theses & Dissertations

Excessive tool wear generated during the plunge phase of Friction Stir Welding has slowed the pace of expanding the Friction Stir Welding process to hard materials such as steel. This research uses a finite element model of the Johnson-Cook material constitutive law to investigate the shear stresses, axial forces, and temperatures experienced by the tool and the workpiece during the plunge stage of Friction Stir Welding. The model in this research was developed using the commercially available finite element analysis software ABAQUS/Explicit and consists of both a deformable workpiece and a deformable tool. By implementing the concept of using a …

Go to article

Influence Of Towing Force Magnitude On The Kinematics Of Supramaximal Sprinting, David A. Clark, Seth Kuhlman, Michelle B. Sabick, Ronald P. Pfeiffer, Nicole A. Knigge Jul 2009

Influence Of Towing Force Magnitude On The Kinematics Of Supramaximal Sprinting, David A. Clark, Seth Kuhlman, Michelle B. Sabick, Ronald P. Pfeiffer, Nicole A. Knigge

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The purpose of this study was to determine the influence of towing force magnitude on the kinematics of supramaximal sprinting. Ten high school and collegiate aged track and field athletes ran 60m maximal sprints under 5 different conditions: non-towed (NT), Tow A (2.0% body weight), Tow B (2.8%BW), Tow C (3.8%BW), and Tow D (4.7%BW). Three-dimensional kinematics of a 4-segment model of the right side of the body were collected starting at the 35m point of the trial. Significant differences were observed in stride length (SL) and horizontal velocity of the center of mass (VH) during Tow C and Tow …

Go to article

Stability Analysis, Modeling, Simulation And Experimental Testing Of An Ems Maglev System With Structural Flexibility, Aravind M. Hanasoge Jul 2009

Stability Analysis, Modeling, Simulation And Experimental Testing Of An Ems Maglev System With Structural Flexibility, Aravind M. Hanasoge

Mechanical & Aerospace Engineering Theses & Dissertations

Vehicle-guideway interaction studies of Magnetically Levitated (Maglev) vehicles indicate that structural flexibility can adversely affect the overall stability and performance of such systems. This is one of the reasons why guideways are generally made very rigid. This in turn leads to increased cost of the overall system since guideway construction forms a significant portion of the overall cost. In this dissertation, the influence of structural flexibility on the stability of Electromagnetic Suspension (EMS) Maglev systems is studied. It is shown how inherently unstable and flexible structure EMS Maglev systems can achieve guaranteed stability by using collocated actuators and sensors, along …

Go to article

Numerical/Experimental Investigation Of Plunge Stage And Effect Of Donor Material In Friction Stir Welding, Saptarshi Mandal Jul 2009

Numerical/Experimental Investigation Of Plunge Stage And Effect Of Donor Material In Friction Stir Welding, Saptarshi Mandal

Mechanical & Aerospace Engineering Theses & Dissertations

Friction Stir Welding (FSW) was developed in 1991 as a robust solid-state joining technique that uses a specially shaped rotating tool to generate heat and plasticize material around the tool. The tool then mixes plasticized material along the joint line to produce the weld. Over the last decade, FSW has become increasingly popular for welding aluminum. The combination of attractive properties of the weld and cost-efficiency has led researchers to investigate the feasibility of using FSW for steel. One of the major impediments for using friction stir welding for harder materials such as steel is tool wear. It is well-documented …

Go to article

Biomechanical Evaluation Of Glenohumeral Joint Stabilizing Muscles During Provocative Tests Designed To Diagnose Superior Labrum Anterior-Posterior Lesions, Vanessa J. C. Wood Jul 2009

Biomechanical Evaluation Of Glenohumeral Joint Stabilizing Muscles During Provocative Tests Designed To Diagnose Superior Labrum Anterior-Posterior Lesions, Vanessa J. C. Wood

Boise State University Theses and Dissertations

Despite considerable advances in the understanding of glenohumeral (GH) biomechanics and glenoid labral pathologies, arthroscopy remains the only definitive means of Superior Labrum Anterior-Posterior (SLAP) lesion diagnosis. Unfortunately, natural GH anatomic variants limit the reliability of radiography. Accurate clinical diagnostic techniques would be advantageous due to the invasiveness, patient risk, and financial cost associated with arthroscopy. Twenty provocative tests designed to elicit labral symptoms as a diagnostic sign have shown promising accuracy by their respective original authors, but later studies generally fail to reproduce those findings. The purpose of this study was to compare the behavior of GH joint stabilizing …

Go to article

Top 10 Checklist - Energy-Efficient Buildings For The Southern United States, Florida Solar Energy Center, James Cummings Jun 2009

Top 10 Checklist - Energy-Efficient Buildings For The Southern United States, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

The following Top Ten Checklist provides recommendations for creating energy efficient commercial buildings in areas with hot and humid summers. Commercial and institutional buildings vary greatly, from one to another, in size, use, and type of construction. For purposes of this Top Ten Checklist we are assuming a medium-sized (20,000 to 50,000 ft2) office building located in areas with hot and humid summers. The issues that are raised here may equally apply to schools, churches, theaters, and some retail buildings.

Go to article

Development Of A Reusable Aerospike Nozzle For Hybrid Rocket Motors, Patrick Lemieux Jun 2009

Development Of A Reusable Aerospike Nozzle For Hybrid Rocket Motors, Patrick Lemieux

Mechanical Engineering

The Department of Mechanical Engineering at the California Polytechnic State University, San Luis Obispo, has developed an innovative program of experimental research and development on hybrid rocket motors (where the fuel and the oxidizer are in different phases prior to combustion). One project currently underway involves the development of aerospike nozzles for such motors. These nozzles, however, are even more susceptible to throat ablation than regular converging-diverging nozzles, due the nature of their flow expansion mechanism. This paper presents the result of a recent development project focused on reducing throat ablation in hybrid rocket motor nozzles. Although the method is …

Go to article

Comparison Of Passive Cervical Spine Flexion In Children And Adults, Jami Saffioti Jun 2009

Comparison Of Passive Cervical Spine Flexion In Children And Adults, Jami Saffioti

Theses and Dissertations

Head trauma is the most frequent injury sustained by children in car crashes, and the neck plays a key role in governing head kinematics during the crash. Pediatric anthropomorphic test devices (ATDs) are used to assess the risk of head injury, yet the pediatric ATD neck is a size-scaled model of the adult ATD neck, with no consideration for the tissue properties and morphological changes during human development. To help understand the effects of maturation on the changes in neck flexion biomechanics, this study compared the passive cervical spine flexion of children to adults in specific age groups (6-8, 9-12, …

Go to article

Applications Of Variation Analysis Methods To Automotive Mechanisms, Robert C. Leishman Jun 2009

Applications Of Variation Analysis Methods To Automotive Mechanisms, Robert C. Leishman

Theses and Dissertations

Variation analysis, or tolerance analysis as it is sometimes called, is typically used to predict variation in critical dimensions in assemblies by calculating the stack-up of the contributing component variations. It is routinely used in manufacturing and assembly environments with great success. Design engineers are able to account for the small changes in dimensions that naturally occur in manufacturing processes, in equipment, and due to operators and still ensure that the assemblies will meet the design specifications and required assembly performance parameters. Furthermore, geometric variation not only affects critical fits and clearances in static assemblies, it can also cause variation …

Go to article

Multiscale Modeling Of Glass Fiber Reinforced Viscoelastic Polymers Subjected To Impact Loads, Victor Ferreira Teixeira Jun 2009

Multiscale Modeling Of Glass Fiber Reinforced Viscoelastic Polymers Subjected To Impact Loads, Victor Ferreira Teixeira

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

New applications for polymer composite materials are occurring at a rapid pace today. These include structural components in the energy, transportation, and biomedical fields.  Many if not all of these new applications will require that part performance is insured with some degree of sustainable damage.  With the growth in the use of composite structures comes the necessity of improved methodologies that can predict more accurately the life and serviceability conditions of composite parts. Damage mechanics in two-phase composite materials is a very complex problem that has challenged researchers for many years. However, most of the available models perform only a …

Go to article

Effectiveness Of Florida's Residential Energy Code: 1979-2009 (Revision Of 1979-2007 Report), Florida Solar Energy Center, Philip W. Fairey Jun 2009

Effectiveness Of Florida's Residential Energy Code: 1979-2009 (Revision Of 1979-2007 Report), Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

The 2007 Florida Legislature authorized the Florida Building Commission (FBC) and Department of Community Affairs (DCA) to evaluate cost effectiveness of energy conservation measures including appliance efficiencies that could be implemented through the Florida Energy Code for certain buildings. Additionally, Governor Crist's Executive Order #07-127 requires the Secretary of DCA to convene the Florida Building Commission for the purposes of revising the Florida Energy Code for Building Construction to increase the energy performance of new construction in Florida by at least 15% from the 2007 Energy Code. The Commission should consider incorporating standards for appliances and standard lighting in the …

Go to article

Labview-Based Fuzzy Controller Design Of A Lighting Control System, Mou-Lin Jin, Ming-Chun Ho Jun 2009

Labview-Based Fuzzy Controller Design Of A Lighting Control System, Mou-Lin Jin, Ming-Chun Ho

Journal of Marine Science and Technology–Taiwan

This paper describes how we design a lighting control system including hardware and software. Hardware includes light sensing circuit, control circuit, and 8255 expanding I/O circuit, PC, and bulb. Sensing circuit uses photo-resistance component to sense the environmental light and then transmit the signal of the lightness to the computer through an 8-bit A/D converter 0804. The control circuit applies reed relay in digital control way to adjust the variable resistor value of the traditional dimmer. Software incorporates LABVIEW graphical programming language and MATLAB Fuzzy Logic Toolbox to design the light fuzzy controller. The rule-base of the fuzzy logic controller …

Go to article

Catamaran Motion Simulation Based On Moving Grid Technique, Ebrahim Jahanbakhsh, Roozbeh Panahi, Mohammad Saeed Seif Jun 2009

Catamaran Motion Simulation Based On Moving Grid Technique, Ebrahim Jahanbakhsh, Roozbeh Panahi, Mohammad Saeed Seif

Journal of Marine Science and Technology–Taiwan

General purpose software is developed to simulate 6-DoF fluid-structure interaction in two-phase viscous flow. It is a VoF-fractional step solver based on the finite-volume discretization which uses a boundary-fitted body-attached hexahedral grid as the motion simulation strategy. As an application, a high-speed planing catamaran is simulated in steady forward motion as well as in turning maneuver. Results are compared with the available data and good qualitative and quantitative agreements are achieved. Numerical schemes and the solution algorithm of the software are consistent and show a good capability to model highly nonlinear ship motions. It can be further developed to represent …

Go to article

Kalman Filter Effective To Hydrologic Routing?, Yang-Liang Jeng, Rong-Che Chen, Chao-He Chang Jun 2009

Kalman Filter Effective To Hydrologic Routing?, Yang-Liang Jeng, Rong-Che Chen, Chao-He Chang

Journal of Marine Science and Technology–Taiwan

Intake-generated tumbling motion has been recently proposed to enhance the turbulence level during compression stroke to promote the combustion rate and reduce operation variations. This study is to investigate the quality of the tumbling motion, especially for the engine with a bowl-in-piston. To overcome the difficulties on the flow visualization caused by the high-speed motion of a real engine, a transparent water-analogy-simulation system is designed based on similarity analysis and fabricated to model the operation of an actual engine. Benchmark tests including the qualitative flow visualization and quantitative full-field measurements using a high-speed PIA system have been conducted to study …

Go to article

Evaporation Effect In Nonlinear Penetration Of High Energy Beam Drilling, Je-Ee Ho, Chen-Lung Yen Jun 2009

Evaporation Effect In Nonlinear Penetration Of High Energy Beam Drilling, Je-Ee Ho, Chen-Lung Yen

Journal of Marine Science and Technology–Taiwan

Due to the inappropriate assumption with the neglect of evaporation effect in previous research, a linear penetration behavior with a significant deviation from the experimental result was usually proposed in the lower energy density region. To remedy the defect, the evaporation mass determined from the difference between the melting rate and flow expulsion by pressure difference is reconsider in this study. With a 2-D quasic-steady model based on the enthalpy theory, the uniform penetration velocity estimated from the Stefan boundary condition provides a special advantage in calculating efficiency. Meantime, the divergent iteration has been effectively avoided by setting up a …

Go to article

Breaking Away From The Laboratory: Using Lean-Computing Technology To Merge Theory-Based Learning And Experimentation, Thomas Connolly, Kathy Schmidt, Javier Kypuros Jun 2009

Breaking Away From The Laboratory: Using Lean-Computing Technology To Merge Theory-Based Learning And Experimentation, Thomas Connolly, Kathy Schmidt, Javier Kypuros

Mechanical Engineering Faculty Publications and Presentations

This ongoing research involves a departure from traditional laboratory instructional practices in that it seeks to forge a closer connection between lecture-based and laboratory courses. As such, the authors have devised a program that: (1) relinquishes a degree of control to students by providing them some flexibility in determining the subject of their experiments and in the development of experimental procedures and protocols, (2) uses mobile experimentation as a powerful and flexible tool in lecture-based coursework, and (3) expands the concept of the “laboratory” to include virtually everything outside of it. A pilot program in mobile experimentation and data acquisition …

Go to article

Evaluation Of The Benefits Of Oxy-Combustion On Emissions From A Compression Ignition Engine, Thomas A. Salt Jun 2009

Evaluation Of The Benefits Of Oxy-Combustion On Emissions From A Compression Ignition Engine, Thomas A. Salt

Theses and Dissertations

In this research the benefits of applying oxy-combustion in a diesel engine to reduce NOx and particulate emissions were evaluated. The addition of oxygen to the intake in conjunction with exhaust gas recirculation (EGR) was shown to reduce NOx without an increase in particulate. Indicated specific NOx and particulate emissions for oxygen-enhanced EGR (O-EGR) and EGR without oxygen addition (normal or N-EGR) were compared at three engine loads. NOx emissions correlated with flame temperature for both N-EGR and O-EGR but were slightly lower at a given flame temperature for O-EGR. Flame temperature reduction for N-EGR was primarily through dilution of …

Go to article

Phase Tunable Holographic Fabrication For Three-Dimensional Photonic Crystal Templates By Using A Single Optical Element, Di Xu, Kevin P. Chen, Ahmad Harb, Daniel Rodriguez, Karen Lozano, Yuankun Lin Jun 2009

Phase Tunable Holographic Fabrication For Three-Dimensional Photonic Crystal Templates By Using A Single Optical Element, Di Xu, Kevin P. Chen, Ahmad Harb, Daniel Rodriguez, Karen Lozano, Yuankun Lin

Mechanical Engineering Faculty Publications

This paper demonstrates a phase tunable holographic fabrication of three-dimensional photonic lattice structures using a single optical element. A top-cut four-side prism is employed to generate five-beam three-dimensional interference patterns. A silica glass slide is inserted into the optical path to adjust the phase of one interfering beam relative to other four beams. The phase control of the interfering laser beam renders the lattice of the interference pattern from a face-center tetragonal symmetry into a high contrast, interconnecting diamondlike symmetry. This method provides a flexible approach to fabricating three-dimensional photonic lattices with improved photonic band structures.

Go to article

Flexible Electronics Using Ion Implantation To Adhere Polymer Substrate To Single Crystal Silicon Substrate, Terry L. Alford, Douglas C. Thompson Jr., Hyunchul Kim, Michael A. Nastasi, James W. Mayer, Daniel Adams Jun 2009

Flexible Electronics Using Ion Implantation To Adhere Polymer Substrate To Single Crystal Silicon Substrate, Terry L. Alford, Douglas C. Thompson Jr., Hyunchul Kim, Michael A. Nastasi, James W. Mayer, Daniel Adams

Department of Mechanical and Materials Engineering: Faculty Publications

An electronic apparatus uses a single crystalline silicon Substrate disposed adjacent to a flexible substrate. The electronic apparatus may be a flexible flat panel display, or a flexible printed circuit board. The flexible substrate can be made from polymer, plastic, paper, flexible glass, and stainless steel. The flexible substrate is bonded to the single crystalline substrate using an ion implantation process. The ion implantation process involves the use of a noble gas Such as hydrogen, helium, Xenon, and krypton. A plurality of semiconductor devices are formed on the single crystalline silicon Substrate. The semi conductor devices may be thin film …

Go to article

Force Chains And Resonant Behavior In Bending Of A Granular Layer On An Elastic Support, Kitti Rattanadit, Florin Bobaru, Konlayut Promratana, Joseph A. Turner Jun 2009

Force Chains And Resonant Behavior In Bending Of A Granular Layer On An Elastic Support, Kitti Rattanadit, Florin Bobaru, Konlayut Promratana, Joseph A. Turner

Department of Engineering Mechanics: Faculty Publications

In this paper we investigate the interaction between a granular layer and an elastic foundation using a coupled Discrete Element Method-Finite Element Method (DEM–FEM) computational model. We use this dynamics code to simulate quasi-static bending of the granular layer and we observe the changes taking place in the structure of the force chains for two cases: with and without rolling resistance. A reversal of the arches formed in the force chains leads to a bending resistance similar to that observed in dynamic experiments on resonant behavior under bending of a layer of sand in a container with an elastic bottom. …

Go to article

Design, Construction And Evaluation Of A Multi Layered Solar Distillation Prototype, Arlen A. Flanagan Jun 2009

Design, Construction And Evaluation Of A Multi Layered Solar Distillation Prototype, Arlen A. Flanagan

BioResource and Agricultural Engineering

Water is arguably the most important resource to any individual; especially in areas of deserts and open oceans where drinkable water suppliers are scarce. The prototype Solar Desalination Unit allows normally undrinkable water to be distilled into a potable source with minimal inputs. The unit’s main power source is focused sunlight to thermally heat water inducing evaporation which is then condensed and collected. While solar desalination has been around for many years, lately more complex designs have been investigated in order to increase yields and efficiency. This paper focuses on the design, construction and testing of a Multi-Plate Solar Desalination …

Go to article

A New State Observer And Flight Control Of Highly Maneuverable Aircraft, S. N. Balakrishnan, Ming Xin Jun 2009

A New State Observer And Flight Control Of Highly Maneuverable Aircraft, S. N. Balakrishnan, Ming Xin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, a new nonlinear observer (θ-D observer) is proposed to estimate the feedback states for optimal control of a highly maneuverable aircraft. This observer is derived by constructing the dual of a recently developed nonlinear optimal control technique-known as the θ-D technique. The θ-D optimal control approach provides an approximate closed-form solution to the Hamilton-Jacobi-Bellman (HJB) equation. An optimal flight controller using this technique is designed for a highly maneuverable aircraft operating at high angle of attack where the θ-D observer is employed to estimate the states for feedback. The structure of this observer is similar to the …

Go to article

A Microfabricated Segmented-Involute-Foil Regenerator For Enhancing Reliability And Performance Of Stirling Engines: Phase Iii Final Report For The Radioisotope Power Conversion Technology Nra Contract Nas3-03124, Mounir B. Ibrahim, David Gedeon, Gary Wood, Jeffrey Mclean Jun 2009

A Microfabricated Segmented-Involute-Foil Regenerator For Enhancing Reliability And Performance Of Stirling Engines: Phase Iii Final Report For The Radioisotope Power Conversion Technology Nra Contract Nas3-03124, Mounir B. Ibrahim, David Gedeon, Gary Wood, Jeffrey Mclean

Mechanical Engineering Faculty Publications

Under Phase III of NASA Research Announcement contract NAS3-03124, a prototype nickel segmented-involute-foil regenerator was microfabricated and tested in a Sunpower Frequency-Test-Bed (FTB) Stirling convertor. The team for this effort consisted of Cleveland State University, Gedeon Associates, Sunpower Inc. and International Mezzo Technologies. Testing in the FTB convertor produced about the same efficiency as testing with the original random-fiber regenerator. But the high thermal conductivity of the prototype nickel regenerator was responsible for a significant performance degradation. An efficiency improvement (by a 1.04 factor, according to computer predictions) could have been achieved if the regenerator was made from a low-conductivity …

Go to article

The Magic Atm, Amber Iraeta, Jason Sy, August Brower Jun 2009

The Magic Atm, Amber Iraeta, Jason Sy, August Brower

Mechanical Engineering

No abstract provided.

Go to article

Electro Mechanical Actuator Test Stand For In-Flight Experiments, Michael Koopmans, Catlin Mattheis, Austin Lawrence Jun 2009

Electro Mechanical Actuator Test Stand For In-Flight Experiments, Michael Koopmans, Catlin Mattheis, Austin Lawrence

Mechanical Engineering

The Prognostic Center of Excellence at NASA Ames is currently researching actuator prognostics, specifically in the application of electro mechanical actuators (EMA’s). Cal Poly ME students Michael Koopmans and Catlin Mattheis and EE student Austin Lawrence have chosen to undertake the task of building a test stand that will be flown in flight while testing EMA’s specific faults. A stand was designed to fit inside a standard 19” rack, take power from the aircraft 3 EMA’s, a computer, data acquisition, and electric magnets switches are powered. A MIL STD 1553 interface is present to allow fault injection. Vibration and temperature …

Go to article

Simulation Of An Oxidizer-Cooled Hybrid Rocket Throat: Methodology Validation For Design Of A Cooled Aerospike Nozzle, Peter Alexander Brennen Jun 2009

Simulation Of An Oxidizer-Cooled Hybrid Rocket Throat: Methodology Validation For Design Of A Cooled Aerospike Nozzle, Peter Alexander Brennen

Master's Theses

A study was undertaken to create a finite element model of a cooled throat converging/diverging rocket nozzle to be used as a tool in designing a cooled aerospike nozzle. Using ABAQUS, a simplified 2D axisymmetric model was created featuring only the copper throat and stainless steel support ring, which were brazed together for the experimental test firings. This analysis was a sequentially coupled thermal/mechanical model. The steady state thermal data matched closely to experimental data. The subsequent mechanical model predicted a life of over 300 cycles using the Manson-Halford fatigue life criteria. A mesh convergence study was performed to establish …

Go to article

Non-Linear Contact Analysis Of Meshing Gears, Chun Hung Lee Jun 2009

Non-Linear Contact Analysis Of Meshing Gears, Chun Hung Lee

Master's Theses

Gear transmission systems are considered one of the critical aspects of vibration analysis, and it contains various potential faults such as misalignment, cracks, and noise. Therefore, it requires vibration monitoring to ensure the system is operating properly. Case mounted accelerometers are frequently used to monitor frequencies in a system. However, it is not a simple task to identify and interpret the acceleration data since there are many gear mesh frequencies present. One of the approaches utilized by researchers to perform gear diagnostic is Finite Element Modeling. This study focuses on stiffness cycle and meshing stiffness of non-linear quasi-static finite element …

Go to article

Development Of An Integrated Solar Heat Pipe System For Improving Building Energy Efficiency., Michael Vincent Albanese Jun 2009

Development Of An Integrated Solar Heat Pipe System For Improving Building Energy Efficiency., Michael Vincent Albanese

Electronic Theses and Dissertations

The one dimensional heat transfer, thermal diode effect of heat pipes makes them ideal for passive solar applications. Gains in a heat pipe passive solar wall are not lost during cloud cover or periods of low irradiation. An experimental model was built to test the performance of a heat pipe passive solar wall in a laboratory setting. Experimental variations included varying fluid fill levels and the addition of insulation along the adiabatic section of the heat pipe. Filling the heat pipe to 120% volume of the evaporator section and insulating the adiabatic section achieved efficiencies of 85%. The average rate …

Go to article

First Prev Next Last