Mechanical Engineering Commons^™

Nebraska Summary: S589 Agco Rt165a, 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 …

Analysis And Prediction Of Effectiveness For Residential Hvac Ductwork, Jinson J. Erinjeri

Doctoral Dissertations

An analysis of residential HVAC ductwork has been performed. Ductwork in 55 homes in Northern Louisiana was tested to determine duct leakage by means of using various measurement techniques to determine the differences between the existing methods as well as the revised method developed in this project referred to as Generalized Subtraction Correction Algorithm (GSCA). A protocol to measure and estimate return leaks at operating pressure was developed. The weighted average return leakage for the homes sampled was determined to be 115 cfm at operating pressure whereas the weighted average duct leakage was determined to be 348 cfm at 25 …

Structural Behavior Of Pvc Pipe Liners Subjected To Seasonal Groundwater Loading, Qing Cai

Doctoral Dissertations

Thin-walled polymeric liners are routinely used to rehabilitate deteriorated underground pipe lines that are structurally sound but have lost their hydraulic integrity. These host pipes are said to be "partially deteriorated" since they can support soil and surface loading. For this case, the pipe liners must only be designed to withstand the pressure of the groundwater that seeps through openings in the host pipe and migrates through the small annular gap between the liner and the host pipe. This external pressure will cause the polymeric liner to slowly deform inward toward the center of the pipe, and the compressive hoop …

Improvement Of Mechanical Properties Of Uv-Curable Resin For High-Aspect Ratio Microstructures Fabricated In Microstereolithography, Su-Do Lee, Jae-Won Choi, In-Baek Park, Chang-Sik Ha, Seok-Hee Lee

Mechanical Engineering Faculty Research

Recently, microstructures fabricated using microstereolithography technology have been used in the biological, medical and mechanical fields. Microstereolithography can fabricate real 3D microstructures with fine features, although there is presently a limited number of materials available for use in the process. Deformation of the fine features on a fabricated microstructure remains a critical issue for successful part fabrication, and part deformation can occur during rinsing or during fabrication as a result of fluid flow forces that occur during movement of mechanical parts of the system. Deformation can result in failure to fabricate a particular feature by breaking the feature completely, spatial …

Fabrication Of Microstructure Array Using The Projection Microstereolithography System, Jae-Won Choi, Young-Myoung Ha, Seok-Hee Lee

Mechanical Engineering Faculty Research

Microstereolithography technology is similar to the conventional stereolithography process and enables to fabricate a complex 3D microstructure. This is divided into scanning and projection type according to aiming at precision and fabrication speed. The scanning MSL fabricates each layer using position control of laser spot on the resin surface, whereas the projection MSL fabricates one layer with one exposure using a mask. In the projection MSL, DMD used to generate dynamic pattern consists of micromirrors which have per side. The fabrication range and resolution are determined by the field of view of the DMD and the magnification of the projection …

Conditions For Capacitor Voltage Regulation In A Five-Level Cascade Multilevel Inverter: Application To Voltage-Boost In A Pm Drive, John Chiasson, Burak Ozpineci, Zhong Du, Leon M. Tolbert

Electrical and Computer Engineering Faculty Publications and Presentations

A cascade multilevel inverter is a power electronic device built to synthesize a desired AC voltage from several levels of DC voltages. Such inverters have been the subject of research in the last several years, where the DC levels were considered to be identical in that all of them were either batteries, solar cells, etc. Similar to previous results in the literature, the work here shows how a cascade multilevel inverter can be used to obtain a voltage boost at higher speeds for a three-phase PM drive using only a single DC voltage source. The input of a standard three-leg …

A Five-Level Three-Phase Hybrid Cascade Multilevel Inverter Using A Single Dc Source For A Pm Synchronous Motor Drive, John N. Chiasson, Burak Ozpineci, Leon M. Tolbert

Electrical and Computer Engineering Faculty Publications and Presentations

The interest here is in using a single DC power source to construct a 3-phase 5-level cascade multilevel inverter to be used as a drive for a PM traction motor. The 5-level inverter consists of a standard 3-leg inverter (one leg for each phase) and an H-bridge in series with each inverter leg, which use a capacitor as a DC source. It is shown that one can simultaneously maintain the regulation of the capacitor voltage while achieving an output voltage waveform which is 25% higher than that obtained using a standard 3-leg inverter by itself.

High Pressure Testing Of Composite Solid Rocket Propellant Mixtures: Burner Facility Characterization, Rodolphe Valentin Carro

Electronic Theses and Dissertations

Much Research on composite solid propellants has been performed over the past few decades and much progress has been made, yet many of the fundamental processes are still unknown, and the development of new propellants remains highly empirical. Ways to enhance the performance of solid propellants for rocket and other applications continue to be explored experimentally, including the effects of various additives and the impact of fuel and oxidizer particle sizes on burning behavior. One established method to measure the burning rate of composite propellant mixtures in a controlled laboratory setting is to use a constant-volume pressure vessel, or strand …

Mechanical Fastener Pull-Out In Recycled Plastic Lumber, Ryan Dusheke

Opportunities for Undergraduate Research Experience Program (OURE)

The purpose of this paper is to present test results for the examination of mechanical fastener pull-out in plastic lumber. The testing was performed on both 1 Od galvanized steel nails, nominally 3" long and 0.148" in diameter, and No. 10 flathead low-carbon steel screws, nominally I" long. l "x6" Trimax plastic lumber, produced by US Plastic Lumber, was used for all testing. Tests were performed in each of the three sides of the boards. To evaluate the performance of the materials in varying conditions, testing was performed at -20°f, room temperature, and 125°f.

Computational Study Of Laminar Separation Bubble Development Over Supersonic Airfoils At Subsonic Speeds, Josiah D. Elliott

Opportunities for Undergraduate Research Experience Program (OURE)

Laminar Separation Bubbles (LSBs) are regions of separated flow that start near the leading edge of an airfoil and reattach further down the airfoil surface. These regions of separation can appear at low angles of attack and can grow significantly as the angle of attack is increased heavily influencing the flow characteristics over the airfoil. Research on this topic is driven by the supersonic business jet industry which has a particular interest in this type of research due to performance requirements in both the subsonic and supersonic flight regimes. This manuscript is focused on the flow developments near the sharp …

Solar Energy For Disaster Response Using Space Program Resources, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Satellite pictures, solar radiation levels on the earth's surface, Global Positioning Satellites (GPS) and other space-related resources are available through the efforts of many people and organizations. Satellites' measurements of these resources can be integrated with resources on earth to assess damage from disasters and evaluate resources available to respond. Space-related resources are currently being used by the American Red Cross, the Federal Emergency Management Agency, county Emergency Managers and other organizations. The widest use is in evaluating utility resources and deploying them for repair and emergency power in response to a disaster. Today's use of state-of-the-art satellite and Geographic …

Exploring Physical Intuition In Elementary Pressure Vessels, Clive L. Dym, Harry E. Williams

All HMC Faculty Publications and Research

It is shown that displacement calculations for two classical ‘chestnuts’ – thick cylinders and spheres under internal and external pressures – present results that are not easily anticipated. Thus, such analyses provide an interesting opportunity for students (and teachers) taking elementary and advanced courses in the strength of materials to explore and perhaps enhance their physical intuition.

A Computational Theory For The Generation Of Solutions During Early Conceptual Design, Cari R. Bryant

Doctoral Dissertations

"Advancement in technology is usually made by building on previous experiences and learning from past successes and failures. However, knowledge transfer in the broad field of product design is often difficult to accomplish. Research has shown that successful component configurations, observed from existing products, can be dissected and stored for reuse; but few computational tools exist to assist designers during the conceptual phase of design. Many well-known manual methods (e.g. brainstorming, intrinsic and extrinsic searches, and morphological analysis) rely heavily on individual bias and experience and are often time intensive, laborious tasks that may not catch solutions that are functionally …

Thermal Characterization Of Microscale Conductive And Nonconductive Wires Using Transient Electrothermal Technique, Jiaqi Guo, Xinwei Wang, Tao Wang

Department of Mechanical and Materials Engineering: Faculty Publications

In this paper, a transient technique is developed to characterize the thermophysical properties of one-dimensional conductive and nonconductive microscale wires. In this technique, the to-be-measured thin wire is suspended between two electrodes. When feeding a step dc to the sample, its temperature will increase and take a certain time to reach the steady state. This temperature evolution is probed by measuring the variation of voltage over the wire, which is directly related to resistance/temperature change. The temperature evolution history of the sample can be used to determine its thermal diffusivity. A 25.4 µm thick platinum wire is used as the …

Lectures In Computational Fluid Dynamics Of Incompressible Flow: Mathematics, Algorithms And Implementations, James M. Mcdonough

Mechanical Engineering Textbook Gallery

From Prologue:

The present lecture notes are written to emphasize the mathematics of the Navier–Stokes (N.–S.) equations of incompressible flow and the algorithms that have been developed over the past 30 years for solving them.

Introductory Lectures On Turbulence: Physics, Mathematics And Modeling, James M. Mcdonough

Mechanical Engineering Textbook Gallery

From Chapter 1:

The understanding of turbulent behavior in flowing fluids is one of the most intriguing, frustrating— and important—problems in all of classical physics.

The problem of turbulence has been studied by many of the greatest physicists and engineers of the 19th and 20th Centuries, and yet we do not understand in complete detail how or why turbulence occurs, nor can we predict turbulent behavior with any degree of reliability, even in very simple (from an engineering perspective) flow situations. Thus, study of turbulence is motivated both by its inherent intellectual challenge and by the practical utility of a …

Compliant High-Precision E-Quintet Ratcheting (Cheqr) Mechanism For Safety And Arming Devices, John A. Kennedy, Larry L. Howell, William Greenwood

Faculty Publications

Ratchet and pawl mechanisms are used in safety applications to provide mechanical isolation between inputs and an output to insure that extreme environmental conditions do not inadvertently allow an unexpected output. These devices have become smaller and are approaching a size regime where traditional precision components, such as precision bearings and springs, are not available. This paper introduces the Compliant High-precision E-Quintet Ratcheting (CHEQR) mechanism as a means of exploiting the advantages of compliant mechanisms to create safety devices that eliminate the need for bearings and springs. The pseudo-rigid-body model was used to design a mechanism with the desired force-deflection …

Vibration Analysis Of A Boat And Dock, Annicka Gunderson

The Journal of Undergraduate Research

A structure is designed to withstand the maximum force that will be applied. In this case a boat dock is examined as a spring system. This exercise uses a typical design for a lake side boat dock, tires for buoys, and an average fishing boat. Vibration analysis can predict when the highest forces will occur. A solution can be found to graph the motion of the dock. In addition to the analytical solution, the MATLAB program is used to visualize the vibrations. With these tools the magnitude and timing of forces can be verified.

Acl Injuries: Do We Know The Mechanisms?, Antonie J. Van Den Bogert, Scott G. Mclean

Mechanical Engineering Faculty Publications

Injuries of the anterior cruciate ligament (ACL) remain a frequent occurrence in many sports activities. Recent research has identified risk factors, and prevention strategies are being developed based on these findings. There is, however, still a limited understanding of the actual injury mechanisms. In this presentation we will review the current knowledge on ACL injury mechanisms, and identify needs and opportunities for further research.

Local Material Properties Meausrement Using Ultrasonic C-Scan Techniques, Dooheon Kim, Tsuchin P. Chu, Ajay Mohan Mahajan

Mechanical Engineering Faculty Research

Mechanical material properties of concrete specimen are evaluated locally and non-destructively using an ultrasonic C-scan system. The time of flight of the sound wave between front surface and back surface for test samples was measured. Local Young's modulus at scanning point and average Young's modulus of entire specimen are calculated. Testing techniques are developed by calibrating the transducer not only to compensate for the time delay but also to control the measurement of properties of interest, such as true density and local thickness. In order to obtain additional mechanical property, such as Poisson's ratio, the transverse velocities of the wave …

Simple Penning Ion Source For Laboratory Research And Development Applications, Joshua L. Rovey, Brandon P. Ruzic, Thomas J. Houlahan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A simple Penning ion generator (PIG) that can be easily fabricated with simple machining skills and standard laboratory accessories is described. The PIG source uses an iron cathode body, samarium cobalt permanent magnet, stainless steel anode, and iron cathode faceplate to generate a plasma discharge that yields a continuous 1 mA beam of positively charged hydrogen ions at 1 mTorr of pressure. This operating condition requires 5.4 kV and 32.4 W of power. Operation with helium is similar to hydrogen. The ion source is being designed and investigated for use in a sealed-tube neutron generator; however, this ion source is …

Thermal Control Of An Occupied Room: Investigating The Use Of Carbon Dioxide Concentration As An Auxiliary Control Variable, Kevin O'Connell, Aidan O'Dwyer

Conference papers

This paper details the theoretical and experimental work done in the examination of the relationship between human generated carbon dioxide concentration and temperature rise in an occupied room. Generation of carbon dioxide by humans is linked to metabolic rate and heat generation. Therefore, carbon dioxide concentration may be used as an indicator of occupancy in a room. Typically, a heating control system will react slowly to changes in room occupancy if temperature is used as the process variable. The aim of the work was to establish if carbon dioxide concentration in the space could be used as an auxiliary control …

Meso-Machining Of Miniature Space System Components, Carlos Ramirez

Open Access Theses & Dissertations

Many industries in engineering and science are focusing more on producing mechanisms and system components of magnitudes smaller than existing products. One of the major technologies associated with these demands is the development of meso scale precision manufacturing systems. Meso scale fabrication involves the scaling down of conventional machining to incorporate the use of familiar materials, such as aluminum, steel, and even titanium for machining miniature components. New techniques in meso scale fabrication allow for the machining of miniature space system components in an efficient manner to meet certain specifications. A description of the processes used to accurately machine a …

Thermal Effectiveness Characteristics Of Low Approach Indirect Evaporative Cooling Systems In Buildings, Ben Costelloe, Donal Finn

Articles

Meteorological enthalpy analysis of temperate and maritime climates above latitude 45°N suggests that the water-side evaporative cooling technique has considerable unrealised potential with contemporary “high temperature” building cooling systems—such as chilled ceilings and displacement ventilation. As low approach conditions are the key to exploiting the cooling potential of the ambient air, thermal performance at such conditions needs to be investigated. To address the research issues, an industrial scale test rig, based on a low approach open cooling tower and plate heat exchanger and designed to maximise evaporative cooling potential, has been constructed. The thermal effectiveness of such systems (as a …

Test 1897: John Deere 7930 Ivt 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 …

Tractor Test 1917: Farmtrac 675 Also 8075, 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 …

A Simple Laboratory Experiment For The Measurement Of Single Phase Permeability, Ali R. Zand, Yuri Sikorski, Matthew S. Sanders, Homayun K. Navaz

Mechanical Engineering Publications

A simple experiment for measuring single-phase permeability of fully saturated porous medium is introduced. The experiment utilizes radial flow of a non-volatile wetting fluid through a porous medium such as ceramic tile, concrete or sand. The radial position of flow front is measured as a function of time and the collected data are analyzed using Darcy's Law to determine the permeability. In addition, the phenomenon of the multiphase flow through the medium with a broad pore size distribution is demonstrated.

Iii Finishing, Lapping, Honing And Polishing: Processes, Characterisation And Novel Techniques-Experimental Research On Ultra-Smooth Surface Polishing Based On Two-Dimensional Vibration Of Liquid, Zhong Ning Guo, X. Z. Huang, Z. G. Huang, Z. Q. Yu, T. M. Yue, Wing Bun Lee

Faculty Publications

No abstract provided.

In-Situ Optimized Pwas Phased Arrays For Lamb Wave Structural Health Monitoring, Lingyu Yu, Victor Giurgiutiu

Faculty Publications

No abstract provided.

Nebraska Summary: S641 Massey Ferguson 7465, 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 …