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Test 2257: John Deere 5125m, Nebraska Tractor Test Lab Jan 2022

Test 2257: John Deere 5125m, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Test 2254: John Deere 5090m, Nebraska Tractor Test Lab Jan 2022

Test 2254: John Deere 5090m, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary 1243s: Fendt 516 Vario Gen3 Diesel, Nebraska Tractor Test Lab Jan 2022

Nebraska Summary 1243s: Fendt 516 Vario Gen3 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary 1242s: Fendt 514 Vario Gen3 Diesel, Nebraska Tractor Test Lab Jan 2022

Nebraska Summary 1242s: Fendt 514 Vario Gen3 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: 1237 John Deere 6r 175 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab Jan 2022

Nebraska Summary: 1237 John Deere 6r 175 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: 1239 John Deere 6r 215diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab Jan 2022

Nebraska Summary: 1239 John Deere 6r 215diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Tractor Summary: 1236 John Deere 6r 165 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab Jan 2022

Nebraska Tractor Summary: 1236 John Deere 6r 165 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: 1233 John Deere 6r 140 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab Jan 2022

Nebraska Summary: 1233 John Deere 6r 140 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Tractor Summary: 1232 John Deere 6r 130 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab Jan 2022

Nebraska Tractor Summary: 1232 John Deere 6r 130 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: 1231 John Deere 6r 120 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab Jan 2022

Nebraska Summary: 1231 John Deere 6r 120 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Tractor Summary: 1230 John Deere 6r 110 Infinitely Variable Transmission, Nebraska Tractor Test Lab Jan 2022

Nebraska Tractor Summary: 1230 John Deere 6r 110 Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Jointly-Learnt Networks For Future Action Anticipation Via Self-Knowledge Distillation And Cycle Consistency, Md Moniruzzaman, Zhaozheng Yin, Zhihai He, Ming-Chuan Leu, Ruwen Qin Jan 2022

Jointly-Learnt Networks For Future Action Anticipation Via Self-Knowledge Distillation And Cycle Consistency, Md Moniruzzaman, Zhaozheng Yin, Zhihai He, Ming-Chuan Leu, Ruwen Qin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Future action anticipation aims to infer future actions from the observation of a small set of past video frames. In this paper, we propose a novel Jointly learnt Action Anticipation Network (J-AAN) via Self-Knowledge Distillation (Self-KD) and cycle consistency for future action anticipation. In contrast to the current state-of-the-art methods which anticipate the future actions either directly or recursively, our proposed J-AAN anticipates the future actions jointly in both direct and recursive ways. However, when dealing with future action anticipation, one important challenge to address is the future's uncertainty since multiple action sequences may come from or be followed by …


Empirical Comparison Of Machine Learning Methods For Wind Power Predictions, Sidny M. Stewart Jan 2022

Empirical Comparison Of Machine Learning Methods For Wind Power Predictions, Sidny M. Stewart

EWU Masters Thesis Collection

No abstract provided.


Determining Thermal Properties Via Parameter Estimation Of A One-Dimensional, Analytical Model, Lauren B. Tomanek Jan 2022

Determining Thermal Properties Via Parameter Estimation Of A One-Dimensional, Analytical Model, Lauren B. Tomanek

Doctoral Dissertations

“In thermal applications, thermal conductivity is used to predict how well a material conducts heat. The accuracy of the magnitude of the thermal conductivity becomes increasingly essential to optimize part geometry. Thermal conductivity can vary significantly from the nominal value due to post-processing. The ASTM standards available to measure thermal conductivity are challenging to reproduce because of the insulated and prescribed temperature boundary conditions that are needed. The research introduces two new methods for estimating thermal conductivity that deliver the same accuracy as the existing ASTM standards and are easier to implement. The methods account for losses in the heating …


A Convolutional Neural Network (Cnn) For Defect Detection Of Additively Manufactured Parts, Musarrat Farzana Rahman Jan 2022

A Convolutional Neural Network (Cnn) For Defect Detection Of Additively Manufactured Parts, Musarrat Farzana Rahman

Masters Theses

“Additive manufacturing (AM) is a layer-by-layer deposition process to fabricate parts with complex geometries. The formation of defects within AM components is a major concern for critical structural and cyclic loading applications. Understanding the mechanisms of defect formation and identifying the defects play an important role in improving the product lifecycle. The convolutional neural network (CNN) has been demonstrated to be an effective deep learning tool for automated detection of defects for both conventional and AM processes. A network with optimized parameters including proper data processing and sampling can improve the performance of the architecture. In this study, for the …


การศึกษาความแม่นยำและความคลุมเคลือในการประมาณตำแหน่งด้วยเครื่องหมายภาพ หลายชิ้น หลายขนาด และหลายระนาบ, ถิรพุทธิ์ ติระพงศ์ธวัช Jan 2022

การศึกษาความแม่นยำและความคลุมเคลือในการประมาณตำแหน่งด้วยเครื่องหมายภาพ หลายชิ้น หลายขนาด และหลายระนาบ, ถิรพุทธิ์ ติระพงศ์ธวัช

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีจุดมุ่งหมายเพื่อเพิ่มความแม่นยำในการหาตำแหน่งด้วยภาพ โดยใช้การหาตำแหน่งของเครื่องหมาย (markers) ในรูปแบบของ ArUco ซึ่งสามารถหาตำแหน่งและมุมเทียบกับกล้องได้ อย่างไรก็ตามเพื่อเพิ่มความสามารถของการวัดตำแหน่งของวัตถุที่มีหลากหลายเครื่องหมายอยู่ในภาพอย่างแม่นยำ งานวิจัยนี้ได้เสนอแนวทางเป็น 3 ขั้นตอน ได้แก่ 1) การเพิ่มจำนวนเครื่องหมาย 2) การใช้เครื่องหมายหลายขนาด 3) การใช้เครื่องหมายหลายระนาบ จากการศึกษาพบว่า 1) การเพิ่มจำนวนเครื่องหมายเป็น 4 เครื่องหมายกระจายอยู่บนวัตถุ และใช้การหาตำแหน่งด้วยวิธี Perspective-n-Point (PnP) pose computation และปรับปรุงผลต่อด้วยเทคนิค Levenberg-Marquardt minimization จะสามารถลดความคลาดเคลื่อนเชิงตำแหน่งและเชิงมุมที่ระยะ 1 เมตรได้ร้อยละ 19.59 และ 41.89 ตามลำดับ 2) การพัฒนาเพิ่มเติมโดยการใช้เครื่องหมายสองขนาดร่วมกัน สามารถลดความคลาดเคลื่อนเชิงตำแหน่งและเชิงมุมที่ระยะ 1 เมตร ได้เพิ่มเติมอีกร้อยละ 41.99 และ 72.89 ตามลำดับ และในขณะเดียวกันสามารถเพิ่มระยะสูงสุดในการตรวจจับได้ จาก 4 เมตร เป็น 8 เมตร 3) นอกจากนี้ยังได้พัฒนาการลดความคลุมเครือในการหาตำแหน่งจากการตรวจจับเครื่องหมายบนหลายวัตถุพร้อมกัน จากการศึกษาพบว่า ระบบที่พัฒนาขึ้นมาสามารถแยกแยะเครื่องหมายบนวัตถุได้อย่างถูกต้อง


การประเมินอายุความล้าของตะไบแบบหมุนทางทันตกรรมหน้าตัดแบบต่าง ๆ โดยใช้ระเบียบวิธีไฟไนต์เอลิเมนต์, ณัชพล นันทประทีป Jan 2022

การประเมินอายุความล้าของตะไบแบบหมุนทางทันตกรรมหน้าตัดแบบต่าง ๆ โดยใช้ระเบียบวิธีไฟไนต์เอลิเมนต์, ณัชพล นันทประทีป

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์นี้มุ่งเน้นไปที่การวิเคราะห์ความเค้น ความเครียด และอายุความล้าของตะไบแบบหมุนนิกเกิลไทเทเนียมโดยใช้ระเบียบวิธีไฟไนต์เอลิเมนต์ ในการศึกษานี้ได้พิจารณาตะไบแบบหมุนที่มีรูปร่างหน้าตัดแตกต่างกัน 4 แบบ ได้แก่ สามเหลี่ยมด้านเท่า, สี่เหลี่ยมจัตุรัส, รูปตัว S และสามเหลี่ยมนูน และได้จำลองให้ตะไบสอดเข้าไปในแบบจำลองคลองรากฟันที่มีความโค้งแตกต่างกัน โดยกำหนดรัศมีโค้งของคลองรากฟันให้มีขนาด 2 มม. 5 มม. และ 8 มม. และมุมโค้งมีขนาด 30 องศา 45 องศา และ 60 องศา ตามลำดับ เพื่อจำลองให้ตะไบเสียรูปไปตามส่วนโค้งของคลองรากฟันเหมือนการทำงานจริงในการรักษาคลองรากฟัน ผลการวิเคราะห์แสดงให้เห็นว่าตะไบรับภาระแกนเดียว โดยมีลักษณะความเค้นและความเครียดเป็นคาบรูปไซน์ จากนั้นจึงพิจารณาแอมพลิจูดของความเค้นและความเครียดสูงสุดในวัฏจักรความล้า ซึ่งพบว่าแอมพลิจูดของความเครียดมีค่าเปลี่ยนแปลงตามรัศมีโค้งและมุมโค้งของคลองรากฟัน โดยรัศมีโค้งมีอิทธิพลต่อแอมพลิจูดของความเครียดมากกว่ามุมโค้งและรูปร่างหน้าตัดของตะไบ ในขณะที่แอมพลิจูดของความเค้นไม่ได้แปรผันตามพารามิเตอร์ของรูปร่างคลองรากฟันดังเช่นกรณีของความเครียด เนื่องจากความสัมพันธ์ของความเค้นและความเครียดของนิกเกิลไทเทเนียมที่ไม่ได้แปรผันตรงต่อกัน นอกจากนี้ ผลการวิเคราะห์ความเค้นและความเครียดถูกนำไปใช้ประเมินอายุความล้าของตะไบโดยใช้วิธีหาอายุความล้าจากความเค้น และหาอายุความล้าจากความเครียด ซึ่งพบว่าวิธีหาอายุความล้าจากความเครียดมีผลการประเมินอายุความล้าที่สอดคล้องมากกว่าวิธีหาอายุความล้าจากความเค้น


Simulation Of Residual Stress Generation In Additive Manufacturing Of Complex Lattice Geometries, Katie Sue Bruggeman Jan 2022

Simulation Of Residual Stress Generation In Additive Manufacturing Of Complex Lattice Geometries, Katie Sue Bruggeman

Browse all Theses and Dissertations

Residual stresses developed during additive manufacturing (AM) can influence the mechanical performance of structural components in their intended applications. In this study, thermomechanical residual stress simulations of the laser powder bed fusion (LPBF) process are conducted for both simplified (plate and cube-shaped) geometries as well as five complex lattice geometries fabricated with Inconel 718. These simulations are conducted with the commercial software package Simufact Additive©, which uses a non-linear finite element analysis and layer-by-layer averaging approach in determining residual stresses. To verify the efficacy of the Simufact Additive© simulations, numerical results for the plate and cube-shape geometries are analyzed for …


Editorial For The Special Issue On Micromachines For Non-Newtonian Microfluidics, Lanju Mei, Shizhi Qian Jan 2022

Editorial For The Special Issue On Micromachines For Non-Newtonian Microfluidics, Lanju Mei, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

In lieu of an abstract, this is an excerpt from the first page.

Microfluidics has seen a remarkable growth over the past few decades, with its extensive applications in engineering, medicine, biology, chemistry, etc [...]


Autoignition Delay Time Measurements And Chemical Kinetic Modeling Of Hydrogen/Ammonia/Natural Gas Mixtures, Jessica Baker Jan 2022

Autoignition Delay Time Measurements And Chemical Kinetic Modeling Of Hydrogen/Ammonia/Natural Gas Mixtures, Jessica Baker

Electronic Theses and Dissertations, 2020-2023

In recent years, hydrogen-carrying compounds have accrued interest as an alternative to traditional fossil fuels due to their function as zero-emission fuels. As such, there is interest in investigating hydrogen-carrying compounds to improve understanding of the fuels' characteristics for use in high pressure systems. In the current study, the oxidation of ammonia/natural gas/hydrogen mixtures was carried out to study CO formation profiles as well as the ignition delay times behind reflected shock waves in order to refine chemical kinetic models. Experiments were carried out in the University of Central Florida's shock tube facility by utilizing chemiluminescence to obtain OH* emission …


Prediction And Validation Of Residual Stresses In Additively Manufactured Metal Parts, Jose Mayi Rivas Jan 2022

Prediction And Validation Of Residual Stresses In Additively Manufactured Metal Parts, Jose Mayi Rivas

Electronic Theses and Dissertations, 2020-2023

Selective Laser Melted (SLM) Additively Manufactured (AM) metal parts are of special interest to many industries because their designs can be made arbitrarily complex while still maintaining bulk type mechanical properties. However, the large thermal gradients inherent to the SLM process generate residual stresses (RS) and distortions that are detrimental to the fit, functionality and integrity of parts. Predicting the state of stresses in as-built 3D printed parts is a difficult problem that currently has only been approached with the use of transient thermomechanical Finite Element Models (FEMs). The nonlinearities associated with AM processes are difficult to capture in these …


Simulation Of A Comprehensive Heat Recovery Steam Generator, Jose Chalarca Castro Jan 2022

Simulation Of A Comprehensive Heat Recovery Steam Generator, Jose Chalarca Castro

Electronic Theses and Dissertations, 2020-2023

With the increasing prevalence of renewables, it is important to optimize combined cycle power plants during transient conditions to better compliment the variable generation of renewable energy generators. There is a demand for dynamic heat recovery steam generators (HRSG) models that may enable improved control designs. Sufficiently accurate real-time simulations of HRSGs may serve as soft sensors and state estimators during transient conditions. Furthermore, real-time simulations of HRSGs can be used for operator training which does not incur the inherit risk of using plant hardware. The focus of this research is on the development towards an integrated dynamic closed loop …


The Fluid Dynamics Of A Spanwise-Morphing Wing: An Experimental And Analytical Study, Kamlesh Joshi Jan 2022

The Fluid Dynamics Of A Spanwise-Morphing Wing: An Experimental And Analytical Study, Kamlesh Joshi

Electronic Theses and Dissertations, 2020-2023

The unsteady forces and fluid flow structure of a morphing wing are investigated for low Reynolds number (Re) flows, i.e., Re < 20,000. The morphing wing is designed to change shape in the spanwise direction in a controlled manner using internal actuation. The two types of wing morphing are studied in this work, i.e., spanwise bending and spanwise twisting. The wing morphing is named based on the overall shape of the wing after it is dynamically morphed.


Modeling Human Control Behavior In Command-Following Tasks, Sajad Koushkbaghi Jan 2022

Modeling Human Control Behavior In Command-Following Tasks, Sajad Koushkbaghi

Theses and Dissertations--Mechanical and Aerospace Engineering

Humans interact with a variety of complex dynamic systems on a daily basis. However, they are often the lesser understood component of human-in-the-loop (HITL) systems. In this dissertation, we present the results of two HITL experiments to investigate the control strategies that humans use when performing command-following tasks. The first experiment is designed to investigate the control strategies that humans use to interact with nonlinear dynamic systems. Two groups of human subjects interact with a dynamic system and perform a command-following task. One group interacts with a linear time-invariant (LTI) dynamic system and the other group interacts with a Wiener …


Quantitative Methods For Total Lifecycle Risk Likelihood And Impact Assessment In Sustainable Product Design Decision Making, Christian Enyoghasi Jan 2022

Quantitative Methods For Total Lifecycle Risk Likelihood And Impact Assessment In Sustainable Product Design Decision Making, Christian Enyoghasi

Theses and Dissertations--Mechanical and Aerospace Engineering

Sustainable products promise significant economic, environmental, and societal benefits. Numerous methods are available for use during the new product development process to identify alternate product designs that optimize sustainability performance. Once any such design is selected and the product is launched, many uncertainties are likely to affect its performance over the total lifecycle. Such uncertainties give rise to risks that can influence the overall product sustainability performance. However, comprehensive quantitative methods to evaluate the likelihood or the impact of different risks to enable sustainable product design decision making are lacking.

This research aims to address this gap by developing a …


Radiative Conductivity Estimation Using Direct Approach For Fibrous Materials, Mohammad Khaleel Jan 2022

Radiative Conductivity Estimation Using Direct Approach For Fibrous Materials, Mohammad Khaleel

Theses and Dissertations--Mechanical and Aerospace Engineering

During planetary entry, space vehicles encounter high loads of thermal energy which requires a thermal protection system. Ablative thermal protection systems are usually made out of fibrous materials that exhibit internal radiation. In order to model the internal radiation response of a thermal protection system one should obtain proper radiative properties as well as thermal properties. The objective of this work is to provide a method that solves for the solid/gas thermal conductivity. Which can be used in coupled detailed radiative analysis.

Keywords: radiative conductivity, fibrous materials, radiative transfer, thermal protection system, P1 approximation, Finite Volume method.


The Effects Of Reference-Command Preview On The Strategies That Humans Use In Command-Following Tasks, Amelia J. S. Sheffler Jan 2022

The Effects Of Reference-Command Preview On The Strategies That Humans Use In Command-Following Tasks, Amelia J. S. Sheffler

Theses and Dissertations--Mechanical and Aerospace Engineering

This thesis presents results from an experiment in which 22 human subjects each interact with a dynamic system 40 times over a one-week period. For each interaction, a subject performs a command-following task, where the reference command is the same for all 22 subjects but different on each trial. The subjects are divided into 2 groups of 11 subjects. One group performs the command-following task without reference-command preview. The other group is provided with 1-s preview of the reference command. The experimental results are used to examine the effects of reference-command preview. For the group with 1-s reference-command preview, the …


Numerical And Scaling Study On Application Of Inkjet Technology To Automotive Coating, Masoud Arabghahestani Dr. Jan 2022

Numerical And Scaling Study On Application Of Inkjet Technology To Automotive Coating, Masoud Arabghahestani Dr.

Theses and Dissertations--Mechanical and Aerospace Engineering

A thorough literature review identified lack of precision control over quality of droplets generated by the currently available industrial sprayers and a growing need for higher quality droplets in the coating industry. Particularly, lack of knowledge and understanding in continuous inkjets (CIJ) and drop-on-demand (DOD) technologies is identified as significant. Motivated by these needs, this dissertation is dedicated to computational fluid dynamics (CFD) and scaling studies to improve existing inkjet technologies and develop new designs of efficient coating with single and/or multiple piezoelectric sensors to produce on-demand droplets. This dissertation study aims at developing a new DOD type coating technology, …


Peridynamic Material Correspondence Models: Bond-Associated And Higher-Order Formulations, Wailam Chan Jan 2022

Peridynamic Material Correspondence Models: Bond-Associated And Higher-Order Formulations, Wailam Chan

Theses and Dissertations--Mechanical and Aerospace Engineering

Peridynamic material correspondence model is able to incorporate material constitutive models directly from classical continuum mechanics theory. However, conventional correspondence model faces two major technical issues for its application to practical problems. The first is the material instability, which results severe oscillations in the predicted displacement fields. The second issue is the length scale effects of materials mechanical behavior at low length scales. This research journey mainly consists of three stages. The first two stages of this research journey focus on the development of the bond-associated peridynamic material correspondence model to inherently remove the material instability. The last stage focuses …


A Physics-Based Model For Frost Buildup Under Turbulent Flow Using Direct Numerical Simulations, ‪Nadim Zgheib, N. Farzaneh, S. Balachandar, S. A. Sherif Jan 2022

A Physics-Based Model For Frost Buildup Under Turbulent Flow Using Direct Numerical Simulations, ‪Nadim Zgheib, N. Farzaneh, S. Balachandar, S. A. Sherif

Mechanical Engineering Faculty Publications

We present a new model for frost buildup under turbulent (and laminar) flow using direct numerical simulations. The physical model consists of two layers, the air and the frost. The air layer is fully resolved and consists of solving for the velocity, temperature, and vapor mass fraction fields. The frost layer thickness is resolved using conservation of mass and energy. Both phases are dynamically coupled using the immersed boundary method. Three-dimensional simulations are conducted in an open-channel configuration. A number of challenges need to be overcome to make these simulations feasible. First, to enforce far-field conditions of zero …