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Full-Text Articles in Mechanical Engineering

Experimental Characterization Of Hydraulic System Sound, Ben Kolb Jan 2019

Experimental Characterization Of Hydraulic System Sound, Ben Kolb

Dissertations, Master's Theses and Master's Reports

The purpose of this research was to establish test methods for characterizing the interaction between the hydraulic fluid and hydraulic hose at clipping points in mobile heavy equipment hydraulic systems. A simple hydraulic circuit test bench was developed and the laboratory axial piston pump was characterized using ISO 10767-1. A direct relationship between the fluidborne noise and structureborne noise present at each hose clip location was observed for a specific operating condition using operating deflection shapes and structureborne noise measurements. This result shows that optimal hose clip placement can be a viable solution to structureborne noise reduction. Additionally, a modal ...


Closed Loop Energy Maximizing Control Of A Wave Energy Converter Using An Estimated Linear Model That Approximates The Nonlinear Froude-Krylov Force, Yaqzan Mohd Yaqzan Jan 2019

Closed Loop Energy Maximizing Control Of A Wave Energy Converter Using An Estimated Linear Model That Approximates The Nonlinear Froude-Krylov Force, Yaqzan Mohd Yaqzan

Dissertations, Master's Theses and Master's Reports

Wave energy converters (WECs) exploit ocean wave energy and convert it into useful forms such as electricity. But for WECs to be successful on a large scale, two primary conditions need to be satisfied. The energy generated must satisfy the network requirements, and second, energy flow from waves to the grid needs to be maximized. In this dissertation, we address the second problem. Most control techniques for WECs today use the Cummins' linear model to simulate WEC hydrodynamics. However, it has been shown that under the application of a control force, where WEC motions are amplified, the linear model diverges ...


Optimal Power Flow Control Of Networked Dc Microgrids, Eddy H. Trinklein Jan 2019

Optimal Power Flow Control Of Networked Dc Microgrids, Eddy H. Trinklein

Dissertations, Master's Theses and Master's Reports

The US military is moving toward the electrification of many weapon systems and platforms. Advanced weapon systems such as high energy radar, electro-magnetic kinetic weapons and directed energy pose significant integration challenges due to their pulsed power electrical load profile. Additionally, the weapons platforms, including ships, aircraft, and vehicles can be studied as a mobile microgrids with multiple generation sources, loads, and energy storage. There is also a desire to extend the mission profile and capabilities of these systems. Common goals are to increase fuel efficiency, maintaining system stability, and reduce energy storage size as typically required to enable pulsed ...


Acoustic Localization Techniques For Application In Near-Shore Arctic Environments, Miles B. Penhale Jan 2019

Acoustic Localization Techniques For Application In Near-Shore Arctic Environments, Miles B. Penhale

Dissertations, Master's Theses and Master's Reports

The Arctic environment has undergone significant change in recent years. Multi-year ice is no longer prevalent in the Arctic. Instead, Arctic ice melts during summer months and re-freezes each winter. First-year ice, in comparison to multi-year ice, is different in terms of its acoustic properties. Therefore, acoustic propagation models of the Arctic may no longer be valid. The open water in the Arctic for longer time periods during the year invites anthropogenic traffic such as civilian tourism, industrial shipping, natural resource exploration, and military exercises. It is important to understand sound propagation in the first-year ice environment, especially in near-shore ...


Development Of A Fused Deposition 3d Printed Buoy And Method For Quantifying Wave Tank Reflections, Samantha G. Swartzmiller Jan 2019

Development Of A Fused Deposition 3d Printed Buoy And Method For Quantifying Wave Tank Reflections, Samantha G. Swartzmiller

Dissertations, Master's Theses and Master's Reports

Testing model scale prototypes is integral to the development of wave energy converter (WEC) technology. Model scale WECs are tested in wave tanks where they are subjected to repeatable wave fields. Their presence in water creates radiated waves that eventually reflect off tank walls disrupting the intended wave field. Fabrication of model scale WECs is another developing aspect of tank testing. Often model WECs are built of foam. Additive manufacturing is a promising alternative although the most common method, fused deposition modeling (FDM) 3D printing, does not typically produce waterproof parts. The goals of this work were 1) develop a ...


Using Frequency Based Substructuring To Optimize Multi-Axis Resonant Plate Shock Tests, Erica M. Jacobson Jan 2019

Using Frequency Based Substructuring To Optimize Multi-Axis Resonant Plate Shock Tests, Erica M. Jacobson

Dissertations, Master's Theses and Master's Reports

Resonant plate pyroshock tests only offer to test one component axis at a time, while the qualification pyroshock tests often have three single-axis specifications to meet. There is an interest in creating a multi-axis test environment from the single-axis resonant plate parts to save testing time, create a more realistic test environment, and monitor the possibility of an overtest. To investigate this, LaGrange-multiplier frequency based substructuring was implemented to virtually arrange the single-axis resonant plate subsystems into different assembly configurations and mathematically calculate the new assembly dynamics. A shock response spectrum was calculated from the new assembly dynamics through an ...


Improved Low-Frequency Impact Insulation Class Measurements Based On Comparison Techniques, Sunit Girdhar Jan 2019

Improved Low-Frequency Impact Insulation Class Measurements Based On Comparison Techniques, Sunit Girdhar

Dissertations, Master's Theses and Master's Reports

In today’s world, noise pollution is growing as a major concern and it is becoming more and more difficult to find quiet places. But when the problem escalates to the extent that people are annoyed with loud noises even in their apartments, it becomes an alarming issue for engineers. Around the world, cities have defined some basic performance requirements for buildings, and isolation of residents from noise is one of the cardinal performance requirements. In the United States, building codes use the Impact Insulation Class (IIC) rating to characterize the performance of floor/ceiling assemblies. This method uses the ...


Comparative Study And Design Of Economical Sound Intensity Probe, Karan Gundre Jan 2019

Comparative Study And Design Of Economical Sound Intensity Probe, Karan Gundre

Dissertations, Master's Theses and Master's Reports

The theory of sound intensity measurement using the two-microphone method was first developed in the late 1970s. Even though the measurements were limited by the technology of the time, the theory was straight-forward and considerable attention was given to improving precision during testing or post-processing. With the development of modern equipment, however, the focus shifted to the apparatus. The commercial intensity probes available today have microphones that are already phase-matched. This eliminates the need for correction during or post-testing as a majority of the errors are minimized before any data is even collected. Although such intensity probes facilitate taking precise ...


Analysis Of The Shock Response Spectrum And Resonant Plate Testing Methods, William Larsen Jan 2018

Analysis Of The Shock Response Spectrum And Resonant Plate Testing Methods, William Larsen

Dissertations, Master's Theses and Master's Reports

Intricacies of the shock response spectrum were discovered and investigated by testing a circular plate structure with integral damping. Effects on the SRS from physical alterations to the nonlinear structure were monitored from low and high shock impulses. A method was developed and validated to estimate high amplitude shock inputs from low amplitude frequency response functions. Finite element models explored variable thickness plate designs.


Control Oriented Modeling Of An Automotive Drivetrain For Anti-Jerk Control, Gurijala Venkat Prithvi Reddy Jan 2018

Control Oriented Modeling Of An Automotive Drivetrain For Anti-Jerk Control, Gurijala Venkat Prithvi Reddy

Dissertations, Master's Theses and Master's Reports

Drivability is an important metric during the development of an automobile. Calibration engineers spend a significant amount of time trying to improve the drivability of vehicles for various driving conditions. With an increase in the available computational power in an automobile, novel model-based methods are being implemented for further improving the drivability, while reducing calibration time and effort. Phenomenon known as clunk and shuffle, which are caused due to backlash and compliance in the driveline, are a major cause of issues related to drivability and noise, vibration and harshness (NVH) during tip-in and tip-out scenarios.

This thesis focuses on developing ...


Commercialization Of The Carbon Nanotube Thermophone For Active Noise Control Applications, Steven A. Senczyszyn Jan 2018

Commercialization Of The Carbon Nanotube Thermophone For Active Noise Control Applications, Steven A. Senczyszyn

Dissertations, Master's Theses and Master's Reports

The rate of commercialization for technology developed in junction with academic institutions has risen dramatically over the past 30 years. Since the introduction of the Bayh-Dole Act in 1980, the amount of intellectual property owned by academic institutions has increased exponentially, and with that, there has also been an increase in the number of university spinouts generated. However, the increase of spinouts does not match the rate of increase in intellectual property. The National Science Foundation has created the Innovation Corps (I-Corps) program to help bridge this gap and provide academic professionals and students the tools necessary to commercialize technology ...


Modeling And Analysis For Driveline Jerk Control, Prince Lakhani Jan 2018

Modeling And Analysis For Driveline Jerk Control, Prince Lakhani

Dissertations, Master's Theses and Master's Reports

In modern-day automotive industry, automotive manufacturers pay keen attention to driver’s safety and comfort by ensuring good vehicle drivability, feel of acceleration, limiting jerk and noise. The vehicle driveline plays a critical role to meet these criteria. By using high-fidelity simulation tool such as AMESim®, it is now possible to accurately model the vehicle driveline to be tested for different scenarios. With Simulink®, one can develop an efficient torque-based control system to limit the driveline oscillations and the generated noise. So, a joint simulation is used which provides a platform to evaluate the estimators and control system while considering ...


Optimization And Control Of An Array Of Wave Energy Converters, Jianyang Lyu Jan 2018

Optimization And Control Of An Array Of Wave Energy Converters, Jianyang Lyu

Dissertations, Master's Theses and Master's Reports

This study explored optimal configuration of both the array layout and the dimension of each WEC in the array. The array contains heaving buoys with full interaction and exact hydrodynamics. Optimization of dimension was done on each WEC in the array with a given optimal layout, and a higher q-factor was achieved. Both impedance matching optimal control and derivative control were employed, which provides both theoretical maximum energy and a more realistic case. Then the work was expanded to optimization of both the array layout and the dimension of each WEC in the array. An average of 39.21% higher ...


The Role Of Active Flow-Control Devices In The Dynamic Aeroelastic Response Of Wind Turbine Rotors, Muraleekrishnan Menon Menon Muraleedharan Nair Jan 2017

The Role Of Active Flow-Control Devices In The Dynamic Aeroelastic Response Of Wind Turbine Rotors, Muraleekrishnan Menon Menon Muraleedharan Nair

Dissertations, Master's Theses and Master's Reports

The significance of wind as a renewable source of power is growing with the increasing capacity of individual utility-scale wind turbines. Contemporary wind turbines are capable of producing up to 8 MW and consequently, their rotor sizes are rapidly growing in size. This has led to an increased emphasis on studies related to improvements and innovations in load-control methodologies. Most often than not, controlling the loads on an operational turbine is a precarious scenario, especially under high wind loading. The up-scaling of turbine rotors would thus benefit from a rationale change in load control through methodologies such as variable-speed stall ...


Electromagnetic Signal Feedback Control For Proximity Detection Systems, Adam K. Smith Jan 2017

Electromagnetic Signal Feedback Control For Proximity Detection Systems, Adam K. Smith

Dissertations, Master's Theses and Master's Reports

Coal is the most abundant fossil fuel in the United States and remains an essential source of energy. While more than half of coal production comes from surface mining, nearly twice as many workers are employed by underground operations.

One of the key pieces of equipment used in underground coal mining is the continuous mining machine. These large and powerful machines are operated in confined spaces by remote control. Since 1984, 40 mine workers in the U. S. have been killed when struck or pinned by a continuous mining machine. It is estimated that a majority of these accidents could ...


Advanced Uses For Carbon Nanotubes: A Spherical Sound Source And Hot-Films As Microphones, Micaela M. Thiery Jan 2017

Advanced Uses For Carbon Nanotubes: A Spherical Sound Source And Hot-Films As Microphones, Micaela M. Thiery

Dissertations, Master's Theses and Master's Reports

Super-aligned carbon nanotube (CNT) thin-film is used to create thermophones. The thermal properties of CNT film allow it to rapidly heat and cool when supplied AC power producing temperature and pressure gradients and, therefore, audible sound. The advantages of CNT thermophones include eliminating all moving components of traditional speakers and reducing the weight of the speaker itself by using CNT film, which is nearly weightless. Additionally, the flexibility of CNT film provides the unique opportunity to construct loudspeakers of various sizes and geometries. In this work, a spherical CNT thermophone is designed, manufactured, and tested for directivity with the overall ...


Model-Based Control Of An Rcci Engine, Akshat Abhay Raut Jan 2017

Model-Based Control Of An Rcci Engine, Akshat Abhay Raut

Dissertations, Master's Theses and Master's Reports

Reactivity controlled compression ignition (RCCI) is a combustion strategy that offers high fuel conversion efficiency and near zero emissions of NOx and soot which can help in improving fuel economy in mobile and stationary internal combustion engine (ICE) applications and at the same time lower engine-out emissions. One of the main challenges associated with RCCI combustion is the difficulty in simultaneously controlling combustion phasing, engine load, and cyclic variability during transient engine operations.

This thesis focuses on developing model based controllers for cycle-to-cycle combustion phasing and load control during transient operations. A control oriented model (COM) is developed by using ...


Simulation Of Human Ankle Trajectory During Stance Phase Of Gait, Leslie Castelino Jan 2017

Simulation Of Human Ankle Trajectory During Stance Phase Of Gait, Leslie Castelino

Dissertations, Master's Theses and Master's Reports

A simulation was developed which mimics the human gait characteristics based on the input of an individual’s gait trajectory. This simulation also estimates the impedance of the human ankle based on the ground reaction forces measured by the force plate. This simulation will accept alterations of the following parameters: total body weight, weight of the shank, weight of the foot, trajectories of the shank and foot of the individual and orientation of the force plate, which would generate a new gait trajectory for the ankle during the stance phase of gait. The goal of this simulation was to validate ...


Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale Jan 2017

Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale

Dissertations, Master's Theses and Master's Reports

In the past century, extensive research has been done regarding the sound propagation in arctic ice sheets. The majority of this research has focused on low frequency propagation over long distances. One of the most commonly used excitation methods for air-ice-water layers has been explosives. However, environmental regulation has become more stringent, disallowing the use of almost all explosive excitation types. Due to changing climate conditions in these environments, new experimentation is warranted to determine sound propagation characteristics in, through, and under thin ice sheets, in shallow water, over short distances. In April, 2016 several experiments were conducted approximately 2 ...


Performance Of Hard Disk Drives In High Noise Environments, Trinoy Dutta Jan 2017

Performance Of Hard Disk Drives In High Noise Environments, Trinoy Dutta

Dissertations, Master's Theses and Master's Reports

Digital information stored in rotational media, such as Hard Disk Drives (HDD) needs to be reliable and readily accessible. Various studies have been performed on the modal analysis of HDDs and the noise emitted during operation. Analysis performed by Siemens Corporation, IBM and Tyco Fire Protection Products show that HDDs are sensitive to noise. This report initially focusses on identifying the critical frequency ranges and the levels of noise where the performance of the drives reduces. A series of tests have been performed using pink noise at one-third octave frequency bands at sound pressure levels ranging from 80 dB to ...


Development Of A High-Fidelity Model And Kalman Filter Based State Estimator For Simulation And Control Of Nox Reduction Performance Of A Scr Catalyst On A Dpf, Venkata Rajesh Chundru Jan 2017

Development Of A High-Fidelity Model And Kalman Filter Based State Estimator For Simulation And Control Of Nox Reduction Performance Of A Scr Catalyst On A Dpf, Venkata Rajesh Chundru

Dissertations, Master's Theses and Master's Reports

Reduction of emissions and improving the fuel consumption are two prime research areas in Diesel engine development. The present after-treatment systems being used for emissions control include diesel oxidation catalyst (DOC) for NO, HC and CO oxidation along with catalyzed particulate filters for PM (particulate matter) and selective catalytic reduction (SCR) for controlling NOx emissions. Recently an after-treatment system called SCR catalyst on a DPF capable of simultaneously reducing both NOx and PM emissions has been developed in order to reduce the overall size of the after-treatment system.

The goal of this proposed research is to create a state estimator ...


Incorporating Driver’S Behavior Into Predictive Powertrain Energy Management For A Power-Split Hybrid Electric Vehicle, Lei Feng Jan 2016

Incorporating Driver’S Behavior Into Predictive Powertrain Energy Management For A Power-Split Hybrid Electric Vehicle, Lei Feng

Dissertations, Master's Theses and Master's Reports

The goal of this series of research is to advance hybrid electric vehicle (HEV) energy management by incorporating driver’s driving behavior and driving cycle information. To reduce HEV fuel consumption, the objectives of this research are divided into the following three parts.

The first part of the research investigates the impact of driver’s behavior on the overall fuel efficiency of a hybrid electric vehicle and the energy efficiency of individual powertrain components under various driving cycles. Between the sticker number fuel economy and actual fuel economy, it is well known that a noticeable difference occur when a driver ...


Experimental Study, Modelling And Controller Design For An Rcci Engine, Naga Nithin Teja Kondipati Jan 2016

Experimental Study, Modelling And Controller Design For An Rcci Engine, Naga Nithin Teja Kondipati

Dissertations, Master's Theses and Master's Reports

Low Temperature Combustion (LTC) has got widespread attention over the past two decades in the field of Automotive Research and Development due to it’s potential for achieving higher efficiencies with near-zero engine out NOx and soot emissions. Among all the LTC strategies Reactivity controlled compression ignition (RCCI) has shown the most promising results due to it’s precise control over combustion phasing and heat release rate. However, RCCI being a dual-fuel stratified combustion, precise control over the injection timing of direct injected fuel and in-cylinder fuel reactivity of the mixture needs to be controlled effectively in order to achieve ...


Methodology For Analyzing Epoxy-Cnt Phononic Crystals For Wave Attenuation And Guiding, Madhu Kolati Jan 2016

Methodology For Analyzing Epoxy-Cnt Phononic Crystals For Wave Attenuation And Guiding, Madhu Kolati

Dissertations, Master's Theses and Master's Reports

Phononic crystals (PhnCs) control, direct and manipulate sound waves to achieve wave guiding and attenuation. This dissertation presents methodology for analyzing nanotube materials based phononic crystals to achieve control over sound, vibration and stress mitigation. Much of the analytical work presented is in identifying frequency band gaps in which sound or vibration cannot propagate through these PhnCs. Wave attenuation and mitigation analysis is demonstrated using finite element simulation. Engineering principles from current research areas of solid mechanics, solid-state physics, elasto-dynamics, mechanical vibrations and acoustics are employed for the methodology. A considerable effort is put to show that these PhnCs can ...


Drive Signal Development For The Thermoacoustic Loudspeaker, Troy Bouman Jan 2016

Drive Signal Development For The Thermoacoustic Loudspeaker, Troy Bouman

Dissertations, Master's Theses and Master's Reports

Carbon nanotube thermophones can create acoustic waves from 1 Hz to 100 kHz. The thermoacoustic effect that allows for this non-vibrating sound source is naturally inefficient. Prior efforts have not explored their true efficiency (i.e. the ratio of the total acoustic power to the electrical input power). All previous works have used the ratio of sound pressure to input electrical power. A method for true power efficiency measurement is shown using a fully anechoic technique. True efficiency data are presented for five different drive signal processing techniques: standard alternating current (AC), direct current added to AC (DCAC), amplitude modulation ...


Design, Fabrication And Analysis Of An Auxiliary Power Unit On A Heavy-Duty Truck To Power The Hvac Systems Of The Truck During Driver Off-Duty Conditions, Rohan Milind Kalurkar Jan 2016

Design, Fabrication And Analysis Of An Auxiliary Power Unit On A Heavy-Duty Truck To Power The Hvac Systems Of The Truck During Driver Off-Duty Conditions, Rohan Milind Kalurkar

Dissertations, Master's Theses and Master's Reports

Currently, one of the biggest challenges the world is facing is energy insufficiency. One of the contributors to energy consumption in United States are the idling semi-trailer trucks. In May 2001, President Bush issued The National Energy Policy in which he directed The Environmental Protection Agency (EPA) and Department of Transportation (DOT) to reduce the idling of trucks. This was done in order to reduce energy consumption by lowering fuel consumption and emissions coming out of semi-trailer trucks in the United States of America.

This project deals with the efforts of installing an Auxiliary Power Unit (APU) as a device ...


Evaluation Of Angular Distribution Of Incident Field At The Transmission Loss Window In Michigan Tech’S Reverberant Chamber, Abhishek Thyagarajan Jan 2016

Evaluation Of Angular Distribution Of Incident Field At The Transmission Loss Window In Michigan Tech’S Reverberant Chamber, Abhishek Thyagarajan

Dissertations, Master's Theses and Master's Reports

Transmission Loss prediction accuracy is highly dependent on a good understanding of the angular distribution of incident field on the panel. Traditionally, the incident field has been assumed to be either completely random (equal probability of incidence at all angles from 0° - 90°) or field incidence (where the field is assumed to be completely diffuse between 0° - 78°). Studies1-3 have shown that these models are not completely representative of the incident field. This incident field is studied in the Michigan Tech Transmission Loss suite using two different methods in this study; beamforming and acoustic intensity. The beamforming method uses a ...


Experimental Investigation Of Cavitation Signatures In An Automotive Torque Converter Using A Microwave Telemetry Technique, Carl L. Anderson, L. Zeng, P. O. Sweger, Amitabh Narain, Jason R. Blough Jan 2003

Experimental Investigation Of Cavitation Signatures In An Automotive Torque Converter Using A Microwave Telemetry Technique, Carl L. Anderson, L. Zeng, P. O. Sweger, Amitabh Narain, Jason R. Blough

Department of Mechanical Engineering-Engineering Mechanics Publications

A unique experimental investigation of cavitation signatures in an automotive torque converter under stall conditions is reported. A quantitative criterion is proposed for predicting early and advanced cavitation in terms of suitable nondimensional pump speeds. The dimensionless pump speed that marks early cavitation is obtained by relating this parameter to the appearance of charge-pressure–dependent pressure fluctuations in the differential pressure transducer readings. The differential pressure transducers were mounted at well-defined locations in the pump passage of a torque converter. The data were transmitted by a wireless telemetry system mounted on the pump housing. Data were received and processed by ...