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

Mechanical Engineering Commons

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

16,314 Full-Text Articles 17,156 Authors 3,119,219 Downloads 110 Institutions

All Articles in Mechanical Engineering

Faceted Search

16,314 full-text articles. Page 1 of 415.

Numerical Modeling Of Fluid-Porous Structure Interaction In Arteries, Rana Zakerzadeh, Paolo Zunino 2016 University of Pittsburgh - Main Campus

Numerical Modeling Of Fluid-Porous Structure Interaction In Arteries, Rana Zakerzadeh, Paolo Zunino

Biology and Medicine Through Mathematics Conference

No abstract provided.


Effects Of Noise, Reverberation And Foreign Accent On Native And Non-Native Listeners’ Performance Of English Speech Comprehension, Zhao Ellen Peng, Lily M. Wang 2016 University of Nebraska - Lincoln

Effects Of Noise, Reverberation And Foreign Accent On Native And Non-Native Listeners’ Performance Of English Speech Comprehension, Zhao Ellen Peng, Lily M. Wang

Lily M Wang

A large number of non-native English speakers may be found in American classrooms, both as listeners and talkers. Little is known about how this population comprehends speech in realistic adverse acoustical conditions. A study was conducted to investigate the effects of background noise level (BNL), reverberation time (RT), and talker foreign accent on native and non-native listeners' speech comprehension, while controlling for English language abilities. A total of 115 adult listeners completed comprehension tasks under 15 acoustic conditions: three BNLs (RC-30, RC-40, and RC-50) and five RTs (from 0.4 to 1.2 s). Fifty-six listeners were tested with speech ...


How Can Occupancy Modeling And Occupancy Sensors Reduce Energy Usage In Academic Buildings: An Application Approach To University Of San Francisco, Paloma R. Duong 2016 University of San Francisco

How Can Occupancy Modeling And Occupancy Sensors Reduce Energy Usage In Academic Buildings: An Application Approach To University Of San Francisco, Paloma R. Duong

Master's Projects

Buildings are amongst the highest energy consumers relative to industry and transportation. They account for 40% of the world’s energy consumption, due to the need for lighting, equipment, heating, cooling and ventilation. Academic buildings are multi-purpose buildings that create a challenge on energy reduction. Most are old and have fixed occupancy schedules, resulting in high energy consumption because these buildings experience significant occupancy variation throughout the day. Five academic buildings were analyzed; their building information, energy consumption data and methods to project energy savings have been analyzed. The case studies presented different strategies on predicting energy savings, but these ...


Energy Models Of The Txaire Houses, Tajudeen Amadu Annafi 2016 University of Texas at Tyler

Energy Models Of The Txaire Houses, Tajudeen Amadu Annafi

Mechanical Engineering Theses

Model calibration is important as its functions improve building models. A calibrated model of the TxAIRE Houses #1 and #2 have been developed using the OpenStudio software. The model was developed and calibrated with data of the year 2014 but can be used predict electricity consumption of any year.

An actual meteorological year (AMY) weather file was also created for the houses which was used for calibration. The data used to develop this weather file were measured on-site which improved the accuracy of the model. It was found that an error difference of -1.0 % and -4.2 % occurred between ...


High-Temperature And High-Power-Density Nanostructured Thermoelectric Generator For Automotive Waste Heat Recovery, Yanliang Zhang, Nicholas Kempf, Luke Schoensee 2016 Boise State University

High-Temperature And High-Power-Density Nanostructured Thermoelectric Generator For Automotive Waste Heat Recovery, Yanliang Zhang, Nicholas Kempf, Luke Schoensee

Yanliang Zhang

Given increasing energy use as well as decreasing fossil fuel sources worldwide, it is no surprise that interest in promoting energy efficiency through waste heat recovery is also increasing. Thermoelectric generators (TEGs) are one of the most promising pathways for waste heat recovery. Despite recent thermoelectric efficiency improvement in nanostructured materials, a variety of challenges have nevertheless resulted in few demonstrations of these materials for large-scale waste heat recovery. Here we demonstrate a high-performance TEG by combining high-efficiency nanostructured bulk materials with a novel direct metal brazing process to increase the device operating temperature. A unicouple device generates a high ...


A Cartesian Immersed Boundary Method To Simulate Stably Stratified Turbulent Flows, Clancy Umphrey, Rey DeLeon, Inanc Senocak 2016 Boise State University

A Cartesian Immersed Boundary Method To Simulate Stably Stratified Turbulent Flows, Clancy Umphrey, Rey Deleon, Inanc Senocak

Inanc Senocak

Turbulent katabatic (downslope) flow under stable stratification over a cool surface remains a poorly understood subject, which finds application in geophysical flows. This work investigates an immersed boundary (IB) formulation within a multi-graphics-processing-unit (GPU) parallel incompressible flow solver to impose velocity and heat flux boundary conditions to simulate fundamental katabatic flows. Prandtl's analytical solution for laminar katabatic flow is used to develop an IB formulation to impose heat flux boundary conditions, and to assess its formal order of accuracy. Direct numerical simulation of turbulent katabatic flow is then performed to investigate the applicability of proposed schemes in the turbulent ...


Capillary Channel Flow (Ccf) Eu2-02 On The International Space Station (Iss): An Experimental Investigation Of Passive Bubble Separations In An Open Capillary Channel, Mark M. Weislogel, Andrew P. Wollman, Ryan M. Jenson, John T. Geile, John F. Tucker, Brentley M. Wiles, Andy L. Trattner, Claire DeVoe, Lauren M. Sharp, Peter J. Canfield, Joerg Klatte, Michael E. Dreyer 2016 Portland State University

Capillary Channel Flow (Ccf) Eu2-02 On The International Space Station (Iss): An Experimental Investigation Of Passive Bubble Separations In An Open Capillary Channel, Mark M. Weislogel, Andrew P. Wollman, Ryan M. Jenson, John T. Geile, John F. Tucker, Brentley M. Wiles, Andy L. Trattner, Claire Devoe, Lauren M. Sharp, Peter J. Canfield, Joerg Klatte, Michael E. Dreyer

Mark M. Weislogel

It would be signicantly easier to design fluid systems for spacecraft if the fluid phases behaved similarly to those on earth. In this research an open 15:8 degree wedge-sectioned channel is employed to separate bubbles from a two-phase flow in a microgravity environment. The bubbles appear to rise in the channel and coalesce with the free surface in much the same way as would bubbles in a terrestrial environment, only the combined effects of surface tension, wetting, and conduit geometry replace the role of buoyancy. The host liquid is drawn along the channel by a pump and noncondensible gas ...


Agricultural Field Robotics For Plant Data Acquisition, Jeremy S. Blackford, Jared Werner, Tyler A. Troyer, Ethan Nutter 2016 university of Nebraska lincoln

Agricultural Field Robotics For Plant Data Acquisition, Jeremy S. Blackford, Jared Werner, Tyler A. Troyer, Ethan Nutter

UCARE Research Products

As the demand for food increases, we are presented with the challenge of producing food more efficiently. With the help of agricultural robots it will be possible to achieve greater yields by the application of seeds, fertilizers and chemicals in the most efficient way possible. With more advanced robotic systems accurate crop data can be obtained to improve farming products and techniques.

Flex-Row is a medium sized agricultural robotic platform built for autonomously traversing through rough fields during multiple crop growing stages. This platform consisting of a flexible frame with the ability to vary both width and height will initially ...


Investigation On Effect Of Acid Wash With Thermocol Ball On Physical Properties Of Knitted Garments, Elias Khalil 2016 World University of Bangladesh (WUB)

Investigation On Effect Of Acid Wash With Thermocol Ball On Physical Properties Of Knitted Garments, Elias Khalil

Textile Engineering

Washing is considered as the final process of garments finishing. Acid washing is one kind of finishing treatment used for making sewn garments aesthetic, fashionable, soft, comfortable and also adding value to the final garments. This paper investigates the effect of the acid washing (with thermocol balls and potassium permanganate) on different physical properties of three knitted garments (Single Jersey 100% Cotton T-shirt, Single Jersey 95% Cotton 5% Spandex T-Shirt and 1 × 1 Rib100% Cotton T-Shirt). Typical washing procedures and techniques were followed and then physical properties were analyzed under standard condition. It is observed that fabric weight, CPI, WPI ...


Walking Simulator Mechanism, Titus Lungu, Igor Tachynskyy, Omri Tayyara 2016 Cleveland State University

Walking Simulator Mechanism, Titus Lungu, Igor Tachynskyy, Omri Tayyara

The Downtown Review

This paper presents the design, simulation, and kinematic evaluation of a mechanism aimed at simulating both the motion and ground reaction forces produced by a human foot while walking. Such a mechanism can be used to test the durability of shoes through life cycle analysis. In attempting to mimic the physical motion of the human foot as closely as possible, the forces experienced by the human foot were also accurately replicated through the incorporation of a non-stationary testing platform. As is shown in the paper, this testing environment allows for simple adjustments to be made in order to simulate different ...


Design And Optimization Of Membrane-Type Acoustic Metamaterials, Matthew G. Blevins 2016 University of Nebraska-Lincoln

Design And Optimization Of Membrane-Type Acoustic Metamaterials, Matthew G. Blevins

Architectural Engineering -- Dissertations and Student Research

One of the most common problems in noise control is the attenuation of low frequency noise. Typical solutions require barriers with high density and/or thickness. Membrane-type acoustic metamaterials are a novel type of engineered material capable of high low-frequency transmission loss despite their small thickness and light weight. These materials are ideally suited to applications with strict size and weight limitations such as aircraft, automobiles, and buildings. The transmission loss profile can be manipulated by changing the micro-level substructure, stacking multiple unit cells, or by creating multi-celled arrays. To date, analysis has focused primarily on experimental studies in plane-wave ...


Temporally And Spatially Resolved Quantification Of Hemodynamic Forces And Endothelial Mechanics, Lori M. Lambert 2016 University of Nebraska-Lincoln

Temporally And Spatially Resolved Quantification Of Hemodynamic Forces And Endothelial Mechanics, Lori M. Lambert

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

The endothelium is a thin layer of endothelial cells that line the interior surface of an artery. Due to their direct contact with blood flow, endothelial cells experience varying hemodynamic forces and respond to these forces by altering their morphology. When plaque and other substances accumulate in the walls of arteries, i.e., atherosclerosis, endothelial cells have abnormal responses to blood flow. Studying atherosclerosis progression is, therefore, a two-fold investigation into 1) the hemodynamic forces that cause endothelial responses, and 2) the biological and mechanical responses of endothelial cells. The ultimate goal of this study was to develop an experimental ...


Optical Analysis And Fabrication Of Micro And Nanoscale Plasmonically Enhanced Devices, Avery M. Hill 2016 University of Arkansas, Fayetteville

Optical Analysis And Fabrication Of Micro And Nanoscale Plasmonically Enhanced Devices, Avery M. Hill

Physics Undergraduate Honors Theses

Plasmonic nanostructures have been shown to act as optical antennas that enhance optical devices due to their ability to focus light below the diffraction limit of light and enhance the intensity of the incident light. This study focuses on computational electromagnetic (CEM) analysis of two devices: 1) GaAs photodetectors with Au interdigital electrodes and 2) Au thin-film microstructures. Experiments showed that the photoresponse of the interdigital photodetectors depend greatly on the electrode gap and the polarization of the incident light. Smaller electrode gap and transverse polarization give rise to a larger photoresponse. It was also shown that the response from ...


Analysis Of Shock-Plugs In Quasi-One-Dimensional Compressible Flow, Matthew Alexander Thompson 2016 Rose-Hulman Institute of Technology

Analysis Of Shock-Plugs In Quasi-One-Dimensional Compressible Flow, Matthew Alexander Thompson

Graduate Theses - Mechanical Engineering

At small length scales, such as in micro-nozzles, the assumption that a shock wave is infinitesimally thin breaks-down due to the thickness of the shock being non-negligible compared to the dimensions of the nozzle. In this thesis, shock waves of finite thickness, or “shock-plugs,” are modeled using the same methods and assumptions as a standard shock wave analysis. Due to the finite thickness of shock-plugs, however, two additional parameters are required in order to account for the differing inlet and exit areas, as well as the pressure on the side walls of the channel. A “typical” micro-nozzle with appropriate dimensions ...


Effects Of Noise, Reverberation And Foreign Accent On Native And Non-Native Listeners’ Performance Of English Speech Comprehension, Zhao Ellen Peng, Lily M. Wang 2016 University of Nebraska - Lincoln

Effects Of Noise, Reverberation And Foreign Accent On Native And Non-Native Listeners’ Performance Of English Speech Comprehension, Zhao Ellen Peng, Lily M. Wang

Architectural Engineering -- Faculty Publications

A large number of non-native English speakers may be found in American classrooms, both as listeners and talkers. Little is known about how this population comprehends speech in realistic adverse acoustical conditions. A study was conducted to investigate the effects of background noise level (BNL), reverberation time (RT), and talker foreign accent on native and non-native listeners' speech comprehension, while controlling for English language abilities. A total of 115 adult listeners completed comprehension tasks under 15 acoustic conditions: three BNLs (RC-30, RC-40, and RC-50) and five RTs (from 0.4 to 1.2 s). Fifty-six listeners were tested with speech ...


Automated Fusegrade Testing Machine, Natalie A. Rayfield, Peter Trzil, Dylan Moore, Colin Roberson, Haley Register 2016 University of Tennessee, Knoxville

Automated Fusegrade Testing Machine, Natalie A. Rayfield, Peter Trzil, Dylan Moore, Colin Roberson, Haley Register

University of Tennessee Honors Thesis Projects

No abstract provided.


Senior Design Project, Lee F. Collier 7737457, Amy Albaugh, Jacob Walker, Justin Church 2016 University of Tennessee, Knoxville

Senior Design Project, Lee F. Collier 7737457, Amy Albaugh, Jacob Walker, Justin Church

University of Tennessee Honors Thesis Projects

No abstract provided.


Determining Annoyance Thresholds Of Tones In Noise, Jennifer M. Francis, Joonhee Lee, Lily M. Wang 2016 University of Nebraska - Lincoln

Determining Annoyance Thresholds Of Tones In Noise, Jennifer M. Francis, Joonhee Lee, Lily M. Wang

Lily M Wang

Building services equipment often produces noise signatures with significant tones in them that can lead to complaints in the built environment. Previous studies have investigated prominence levels of assorted tonal frequencies, but it is still unclear what prominence of the tones across varying tonal frequencies can lead to human annoyance. This project seeks to apply two different methods towards defining annoyance thresholds of tones in noise at two tonal frequencies: 125 Hz and 500 Hz. In the first, subjects are asked to perform a task, while exposed to ten minutes of a broadband noise spectrum with a specific level of ...


Assessment Of Noise-Induced Annoyance By Tones In Noise From Building Mechanical Systems, Joonhee Lee, Lily M. Wang 2016 University of Nebraska - Lincoln

Assessment Of Noise-Induced Annoyance By Tones In Noise From Building Mechanical Systems, Joonhee Lee, Lily M. Wang

Lily M Wang

Prominent tones in noise generated by mechanical equipment in buildings can cause complaints from occupants in buildings. The ISO 1996-2 and ANSI S1.13 standards describe methodologies and metrics to quantify tonality perception, but the influence of tones in noise on human annoyance and performance is not fully understood yet. This paper investigates annoyance responses of humans while exposed to background noise with tonal components. Twenty participants completed digit span tasks while exposed to noise signals with differing levels of tones and overall loudness. Subjects were also asked to rate their annoyance after completing tasks under each noise signal. The ...


The Impact Of Building Acoustics On Speech Comprehension And Student Achievement, Lily M. Wang 2016 University of Nebraska - Lincoln

The Impact Of Building Acoustics On Speech Comprehension And Student Achievement, Lily M. Wang

Lily M Wang

The movement for improved classroom acoustics has primarily been grounded on studies that show how building acoustics (i.e. background noise levels and room reverberation) affect speech intelligibility, as determined by speech recognition tests. What about actual student learning, though? If students do not understand each spoken word in the classroom perfectly, can they still manage to achieve high scholastic success? This presentation will review two recent studies conducted at the University of Nebraska – Lincoln, linking classroom acoustic conditions to student learning outcomes and speech comprehension (rather than simply recognition). In the first, acoustic measurements in two public school districts ...


Digital Commons powered by bepress