Mechanical Engineering Commons^™

Fsec Approved Solar Energy Systems: Domestic Hot Water And Pool Heating, Florida Solar Energy Center, John Harrison

FSEC Energy Research Center®

This listing contains Florida Energy Factors for solar domestic hot water systems that have been approved by the Florida Solar Energy Center (FSEC) for use in the State. These energy factors represent the dimensionless ratio of the hot water energy made available by each approved system divided by the electrical energy used by the system. The Florida Energy Factor (FEF) is used to determine hot water credit multipliers for residential solar water heating systems in the 1993 Florida Energy Efficiency Code for Building Construction. The FEF can also be used to compare the efficiency of solar water heating systems with …

Reynolds-Stress Turbulence Model In The Kiva Code For Engine Simulation, Yeow-Khern Siow

Dissertations, Master's Theses and Master's Reports - Open

A Reynolds-Stress Turbulence Model has been incorporated with success into the KIVA code, a computational fluid dynamics hydrocode for three-dimensional simulation of fluid flow in engines. The newly implemented Reynolds-stress turbulence model greatly improves the robustness of KIVA, which in its original version has only eddy-viscosity turbulence models. Validation of the Reynolds-stress turbulence model is accomplished by conducting pipe-flow and channel-flow simulations, and comparing the computed results with experimental and direct numerical simulation data. Flows in engines of various geometry and operating conditions are calculated using the model, to study the complex flow fields as well as confirm the model’s …

Cool Flames In Propane-Oxygen Premixtures At Low And Intermediate Temperatures At Reduced-Gravity, Howard Pearlman, Michael R. Foster, Devrez Karabacak

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

No abstract provided.

Power Characteristics Of Industrial Air Compressors, Chris Schmidt, J. Kelly Kissock

Mechanical and Aerospace Engineering Faculty Publications

The power draw characteristics of air compressors are primarily determined by the type of compressor control and the relationship between the compressor’s output capacity and the compressed air demand in the plant. In this paper, we review the most common types of compressor control for small reciprocating and rotary air compressors, and derive relations for estimating compressed air output as a function of the type of control and motor loading. Using these relations, we develop a method to estimate the ratio of compressed air output to energy input, which we call the average operating efficiency, based on input power to …

Test 2087: New Holland Tm130 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Ole Miss Engineer 2003

Ole Miss Engineer

No abstract provided.

Air Handler Leakage: Field Testing Results In Residences, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Testing was performed to characterize air leakage in 30 air handler cabinets and at connections to supply and return ductwork. Operating pressures were measured in the air handler and plenums. Q 0.1 (Q 25) in the air handler averaged 23.9 cfm (11.3 l/s) in 30 homes. Leakage at the return and supply ductwork connections averaged 3.9 Q 0.1 (1.8 l/s Q 25) and 2.2 Q 0.1 (1.0 l/s Q 25), respectively. Actual return side leakage of 77.5 cfm (36.6 l/s) and supply side leakage of 3.1 cfm (1.5 l/s) are calculated based on Q 0.1 (Q 25) and measured operating …

Test 2085: New Holland Tm120 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Nebraska Summary: S319 Challenger Mt 565, 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 …

Acoustic Communication In Two Freshwater Gobies: Ambient Noise And Short-Range Propagation In Shallow Streams, Marco Lugli, Michael L. Fine

Biology Publications

Noise is an important theoretical constraint on the evolution of signal form and sensory performance. In order to determine environmental constraints on the communication of two freshwater gobies Padogobius martensii and Gobius nigricans, numerous noise spectra weremeasured from quiet areas and ones adjacent to waterfalls and rapids in two shallow stony streams. Propagation of goby sounds and waterfall noise was also measured. A quiet window around 100 Hz is present in many noise spectra from noisy locations. The window lies between two noise sources, a low-frequency one attributed to turbulence, and a high-frequency one (200–500 Hz) attributed to bubble …

Experimental Energy Performance Of Open Cooling Towers Used Under Low And Variable Approach Conditions For Indirect Evaporative Cooling Of Buildings, Ben Costelloe, Donal Finn

Articles

The success of chilled ceilings and displacement ventilation systems as a means of sensible cooling in buildings has prompted a review of evaporative cooling technology as an effective means of generating the required cooling water. When such cooling water is generated at low approach conditions (2–5 K), at the higher temperatures required in these systems (14–18°C), very high levels of availability result. In many north western European locations the levels of availability are such that the prospect of supplanting rather than simply supplementing the refrigeration system, for sensible cooling purposes, arises. The viability of the technique, however, largely depends on …

Tests 2078 & 2093: Case Ih Jx 90u Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 1817: John Deere 7420 Powrquad Diesel 20-Speed, 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 …

On The Analysis Of Small Displacements Of Truss Joints, Clive L. Dym, Harry E. Williams

All HMC Faculty Publications and Research

By emphasizing the kinematic aspects and implications of strain in truss analysis, it is shown that joint displacements can be computed in a straightforward manner.

Analytical And Fea Analysis Of Silicon Micro-Machined Capacitive Pressure Sensor, Eoghan O'Donoghue

Theses

This thesis is concerned with the electro-mechanical characterisation of MEMS capacitive pressure sensors and the determination of models to describe their behaviour.

The finite element software package ANSYS is validated as a tool for the examination of the electro-mechanical behaviour of capacitive pressure sensors. It is then used to incorporate the effects of applied load, voltage and residual stress into a model of the sensor structure. The capacitive pressure sensor is modelled both in 3D and also in 2D axis-symmetric modes. The error between the 2D and 3D models is quantified.

The behaviour of structures under electrostatic actuation is investigated. …

Thermal Assessment Of Silicon-Based Composite Materials Used In Photovoltaics, Pavlos K. Bataglannis

Theses

Photovoltaics are devices that convert sunlight directly to electricity. It is well established that the conversion efficiency of mono and poly-crystalline silicon-based photovoltaic modules is inversely related to their temperature. Substantial improvements in operational performance can thus be achieved if the thermal energy accumulating in the material can be effectively dissipated.

Accurate modelling of modules would allow possible methods of thermal dissipation to be evaluated, and as a crucial component of the model, the thermal properties of the constituent materials of PV modules needed to be known. Special consideration needed to be given to the interfaces between dissimilar materials and …

Comparison Of 3-, 5-, And 6-Phase Machines For Automotive Charging Applications, B. Zhang, Hua Bai, Walter Eversman, Ronald J. Krefta, Duane J. Buening, Steven Pekarek, Gregory R. Holbrook

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, the performance of a 5-phase claw-pole machine/converter system is compared with those of 3-phase and 6-phase systems of the same volume. It is shown that the acoustic output of the 5-phase machine compares favorably with that of the 6-phase machine and is much lower than that of the 3-phase machine over a majority of the operating range. In addition, the output current produced by the 5-phase machine Is, in general, 6-8% higher than those of the 3-phase and 6-phase machines. These results suggest that for maximizing power density while minimizing cost and acoustic noise, 5-phase machines provide …

A Single-Element Tuning Fork Piezoelectric Linear Actuator, J. Satonobu, K. Nakamura, S. Ueha, Daniel S. Stutts, James R. Friend

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper describes the design of a piezoelectric tuning-fork, dual-mode motor. The motor uses a single multilayer piezoelectric element in combination with tuning fork and shearing motion to form an actuator using a single drive signal. Finite-element analysis was used in the design of the motor, and the process is described along with the selection of the device's materials and its performance. Swaging was used to mount the multilayer piezoelectric element within the stator. Prototypes of the 25-mm long bidirectional actuator achieved a maximum linear no-load speed of 16.5 cm/s, a maximum linear force of 1.86 N, and maximum efficiency …

Approximate Dynamic Programming Based Optimal Neurocontrol Synthesis Of A Chemical Reactor Process Using Proper Orthogonal Decomposition, Radhakant Padhi, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The concept of approximate dynamic programming and adaptive critic neural network based optimal controller is extended in this study to include systems governed by partial differential equations. An optimal controller is synthesized for a dispersion type tubular chemical reactor, which is governed by two coupled nonlinear partial differential equations. It consists of three steps: First, empirical basis functions are designed using the "Proper Orthogonal Decomposition" technique and a low-order lumped parameter system to represent the infinite-dimensional system is obtained by carrying out a Galerkin projection. Second, approximate dynamic programming technique is applied in a discrete time framework, followed by the …

How To Establish Successful Cooperative Student Learning Centers For Stem Courses, Ronald James Bieniek, Douglas R. Carroll, Cesar Mendoza, Oran Allan Pringle, Ekkehard Sinn, Kai-Tak Wan, Donald C. Wunsch

Physics Faculty Research & Creative Works

Students learn more if they are actively involved in the learning process, particularly in a cooperative manner. Several UMR faculty have operated course-based learning centers (LCs) as part of the campus-wide Learning Enhancement Across Disciplines (LEAD) Program of student learning assistance and enhancement. LCs are designed to assist large numbers of students in a cost- and time-efficient manner that promotes student engagement without requiring undue amounts of faculty time. Course instructors spend time in the open learning environment of the LC, in lieu of office hours, guiding students to master course material and skills in their evolution from novice to …

A Product Architecture-Based Conceptual Dfa Technique, Robert B. Stone, Daniel A. Mcadams, Varghese J. Kayyalethekkel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A conceptual design for assembly (DFA) method is introduced in this paper. The method incorporates DFA analysis into the conceptual design phase. Current DFA methods, essentially all of which are post-design DFA analyses, are reviewed with emphasis on the popular Boothroyd and Dewhurst method. The product architecture-based conceptual DFA method developed and presented in this article uses two relatively new concepts: the functional basis and the method of module heuristics. The functional basis is used to derive a functional model of a product in a standard language and the module heuristics are applied to the functional model to identify a …

Modeling Fracture In Laminated Automotive Glazing Impacted By Spherical Featureless Headform, Lokeswarappa R. Dharani, S. R. Mettu, S. Zhao, S. D. Barbat, L. Chai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laminated glass consisting of two soda lime glass plies adhered by a polyvinyl butyral interlayer (PVB) is used for automotive glazing. This paper describes the application of a dynamic, nonlinear finite element method to investigate the failure modes of a laminated glass subjected to low-velocity impact with a spherical head form. Crack type, crack location and crack initiation time are evaluated using the maximum principal stress and J-integral criterion. Failure occurred due to flexural stresses and not bearing stresses. the first crack always initiated at the center of the outer impacted ply and PVB interface, and later on the exterior …

Multidimensional, Time-Accurate Cfd Simulation Of Adsorption/Desorption In A Carbon Canister, Xingyan Bai, Kakkattukuzhy M. Isaac, D. Klein, R. Banerjee, J. Edson, W. Breig, L. Oliver

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Computational fluid dynamics simulations of fixed-bed adiabatic adsorption/desorption processes are presented in this paper. Linear driving force model is used for heat and mass transfer rates. a two-dimensional cylindrical canister and three-dimensional automotive production canister geometry are used to study the adsorption/desorption processes of carbon dioxide in helium carrier gas on Norit B4 activated carbon. the two-dimensional results compare well with the results of Hwang et al. [1]. Computational results as breakthrough curve, adsorption amount and temperature profiles are provided. Results show that non-adiabatic model should be used to fully utilize the activated carbon bed capacity prior to breakthrough. Copyright …

Numerical Study Of Two-Dimensional Secondary Injection Into A Mach 3.5 Freestream, Stephen C. Coghill

Mechanical & Aerospace Engineering Theses & Dissertations

Upstream interaction within a dual-mode scramjet engine is investigated numerically. The upstream interaction is investigated by increasing the freestream-to-injector pressure ratio. The constant area duct and sudden expansion geometries are used to achieve these results. Analysis using the symmetry boundary condition is compared to the full boundary condition for the constant area duct. Numerical analysis of the Mach 3.5 freestream is conducted using normal sonic injection of nitrogen gas to create the upstream interaction. Comparisons, where applicable, are made to experimental results. Due to the high speed of the flowfield, oblique shockwaves are present causing numerical convergence difficult to achieve. …

Development Of An Aggregation Methodology For Risk Analysis In Aerospace Conceptual Vehicle Design, Trina Marsh Chytka

Engineering Management & Systems Engineering Theses & Dissertations

The growing complexity of technical systems has emphasized a need to gather as much information as possible regarding specific systems of interest in order to make robust, sound decisions about their design and deployment. Acquiring as much data as possible requires the use of empirical statistics, historical information and expert opinion. In much of the aerospace conceptual design environment, the lack of historical information and infeasibility of gathering empirical data relegates the data collection to expert opinion.

The conceptual design of a space vehicle requires input from several disciplines (weights and sizing, operations, trajectory, etc.). In this multidisciplinary environment, the …

A Thermal Time-Constant Experiment, Kyle Ressler, Kyle Brucker, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

A simple experiment, well suited for an undergraduate course in mechatronics, is described in which thermal time-constant information is extracted from a heater-blower table-top system. In the experiment, a thermistor measures the temperature of a resistive-heater that is cooled by a blower and a microcontroller is used for data acquisition. The student is asked to determine the thermal time response, and in particular the thermal time-constant of the system, for different blower speeds. The experiment prompts questions about modeling a thermal system, and exposes the student to basic concepts of mechatronics including measurement and data analysis.

Thermomechanical Behavior Of Rotor With Rubbing, Jerzy T. Sawicki, Alberto Montilla-Bravo, Zdzislaw Gosiewski

Mechanical Engineering Faculty Publications

This article presents an analytical study of the dynamics and stability of rotors subjected to rubbing due to contact with seals, taking account of associated thermal effects. The seal interaction force acting on the shaft gives rise to a friction force, which is a source of heating and can induce so-called spiral vibrations. A mathematical model that has been developed couples the heat-conduction equation with the equations for motion of the rotor. Numerical simulations have been conducted that show the thermomechanical behavior of the rotor at various operating conditions. A procedure for analyzing the stability of multibearing rotors based on …

Air Intake Cooling Motor Vehicle Performance Enhancement, James Brunton, David Kennedy, John D. Kelleher

Articles

This research examined the practical effects of cooling the intake air, on the combustion characteristics of a modern motor vehicle operating under simulated road conditions as well as its subsequent impact on the environment. The cooling effect was achieved by taking a typical air conditioning rig as fitted to a modern motor vehicle and incorporating it into the induction system of the car. The test vehicle used was a 1993 Renault Safrane 2.0Vi standard passenger car that was modified as part of the research to facilitate the extraction of the required test information. A series of tests were conducted using …

Indirect Evaporative Cooling Potential In Air-Water Systems In Temperate Climates, Ben Costelloe, Donal Finn

Articles

Recent developments have prompted a review of evaporative cooling technology as an effective means of cooling modern deep plan buildings. Prominent among these developments is the success of high temperature sensible cooling systems, particularly, chilled ceilings, which require a supply of cooling water at 14–18 °C. Crucial to the success of evaporative cooling technology, as a significant means of cooling in modern applications, is the ability to generate cooling water, in an indirect circuit, at a temperature which closely approaches the ambient adiabatic saturation temperature (AST) or wet bulb temperature (WBT). Recent experimental research has demonstrated that it is technically …

Test 1816: John Deere 7220 Powrquad Diesel 16-Speed, 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 …