Mechanical Engineering Commons^™

Energy Efficiency In Additive Manufacturing: Condensed Review, Ismail Fidan, Vivekanand Naikwadi, Suhas Alkunte, Roshan Mishra, Khalid Tantawi

Engineering Technology Faculty Publications

Today, it is significant that the use of additive manufacturing (AM) has growing in almost every aspect of the daily life. A high number of sectors are adapting and implementing this revolutionary production technology in their domain to increase production volumes, reduce the cost of production, fabricate light weight and complex parts in a short period of time, and respond to the manufacturing needs of customers. It is clear that the AM technologies consume energy to complete the production tasks of each part. Therefore, it is imperative to know the impact of energy efficiency in order to economically and properly …

Numerical Simulation Of The Donor-Assisted Stir Material For Friction Stir Welding Of Aluminum Alloys And Carbon Steel, Joseph Maniscalco, Abdelmageed A. Elmustafa, Srinivasa Bhukya, Zhenhua Wu

Mechanical & Aerospace Engineering Faculty Publications

In this research effort, we explore the use of a donor material to help heat workpieces without wearing the tool or adding more heat than necessary to the system. The donor material would typically be a small piece (or pieces) of material, presumably of lower strength than the workpiece but with a comparable melting point. The donor, a sandwich material, is positioned between the tool head and the material to be welded, where the tool initially plunges and heats up in the same manner as the parent material that is intended for welding. The donor material heats up subsequent to …

High-Throughput Computation Of Interfacial Thermal Management Of Wide-Bandgap Semiconductors, Hao-Wen Chen

Theses and Dissertations

As semiconductor electronics, in particular high electron mobility transistors, get hot in operation, people are trying to incorporate different semiconductor materials to solve the problem of heat dissipation to maintain the device efficiency and performance. In this master thesis, two different packages, LAMMPS and almaBTE, that are focusing on micro-scale and atomic scale respectively, are used to simulate the heat transfer process across interfaces in two different scales. In the LAMMPS simulation, the research is exploring how the location of atoms and the thickness of interfacial layers will influence the interfacial thermal conductance. On the other hand, using the almaBTE …

Hybrid Phase-Change Lattice Boltzmann Simulation Of Vapor Condensation On Vertical Subcooled Walls, Wandong Zhao, Yuan Gao, Ruijie Li, Songgang Qiu, Yin Zhang, Ben Xu

Mechanical Engineering Faculty Publications and Presentations

Saturated vapor condensation on homogenous and heterogeneous subcooled walls is presented in this study by adopting a hybrid phase-change multiple-relaxation-time Lattice Boltzmann model. The effects of wall wettability on the condensation process, including droplets’ growth, coalescence and falling, and the influence of vapor flow to condensation are investigated. The results demonstrate that the heat fluxes around the triple-phase contact lines are higher than that in other cold areas in homogeneous subcooled walls, which actually indicates the fact that filmwise condensation is preventing the continuous condensation process. Furthermore, the dropwise condensation can be formed more easily on the heterogeneous surface with …

Enhanced Heat Transfer In Spray Cooling Through Surface Modifications: An Experimental And Computational Study, Azzam Saadi Salman

Theses and Dissertations

Today, dissipating high heat flux safely is one of the greatest challenges for thermal engineers in thermal management systems, and it becomes a critical barrier to technological developments for many engineering applications. Due to technological advances and aggressive micro-miniaturization of electronic components, the surface area of most devices has shrunk while the computational power increased exponentially. Therefore, the amount of heat dissipated from surfaces has increased significantly. Numerous cooling techniques have been introduced to replace the traditional air cooling systems and to maintain the efficiency and reliability of electronic components. Microelectronics work efficiently and safely at surface temperatures of < 100 ℃ and 125 ℃ for general and defense applications, respectively. One of the proposed alternative schemes is spray cooling, which is considered one of the most advanced cooling methods. It is used for high and ultra-high heat flux dissipation, as it can dissipate 150-200 W/cm2 while maintaining the surface temperature within this range. Also, spray cooling removes a large amount of energy at a lower liquid flow rate compared to other cooling techniques, such as jet impingement and microchannel heat sink. The thermal performance of spray cooling systems can be enhanced either actively or passively. Active enhancement is a very efficient technique; however, it adds more pumping power. The present work focuses on three main objectives: evaluating and analyzing spray cooling performance, developing a three-dimensional numerical multi-phase model for heat transfer process in spray cooling and enhancing the thermal performance of spray cooling passively.

First, …

Development Of Scalable And Tunable Super- Hydrophilic And - Hydrophobic Coatings On The Cu Substrate For Phase Change Heat Transfer Applications, Raikan Saad Dawas

Theses and Dissertations

The aim of this study is to enhance and sustain the thin liquid film evaporation (TLFE) as well as dropwise condensation (DWC) on scalable copper substrates. The current dissertation consists of two sections. The objective of the first section is to enhance the dry cooling technology which is widely used in industrial applications such as in the air side of power plants, AC unit, or electronic cooling. However, the thermal dissipation performance is limited with low heat transfer coefficients (HTCs) due to the low thermal conductivity and density of the air. Inspired by the phase change heat transfer during the …

Optimization Of Analytical Inverse Heat Transfer Recovery Solution, Nathan Schick

Masters Theses

This thesis describes the different methods used when trying to solve inverse heat transfer problems, particularly those involving recovering heat flux. There are currently several techniques to measure the temperature history in an object subjected to heat transfer using various temperature sensors, however these types of sensors are gradually being replaced by Temperature Sensitive Paints (TSP), a technique that is more accurate and provides a better spatial resolution. TSP is a polymer that is applied on a base object. Changes in temperature in the polymer result in variations of the luminescence intensity in the paint. These variations can be captured …

Impact Of Hysteresis Heating Of Railroad Bearing Thermoplastic Elastomer Suspension Pad On Railroad Bearing Thermal Management, Oscar O. Rodriguez, Arturo A. Fuentes, Constantine Tarawneh

Mechanical Engineering Faculty Publications and Presentations

It is a known fact that polymers and all other materials develop hysteresis heating due to the viscoelastic response or internal friction. The hysteresis or phase lag occurs when cyclic loading is applied leading to the dissipation of mechanical energy. The hysteresis heating is induced by the internal heat generation of the material, which occurs at the molecular level as it is being disturbed cyclically. Understanding the hysteresis heating of the railroad bearing elastomer suspension element during operation is essential to predict its dynamic response and structural integrity, as well as to predict the thermal behavior of the railroad bearing …

Electrical Response Of Thermoelectric Generator To Geometry Variation Under Transient Thermal Boundary Condition, Elias Yazdanshenas, Alireza Rezania, Meysam Karami Rad, Lasse Rosendahl

Mechanical & Aerospace Engineering Faculty Publications

A three-dimensional numerical model is applied in this study to illustrate the electrical response of a thermoelectric generator (TEG) during transient heat flux at the hot side. In this work, various types of thermal boundary conditions are considered to evaluate the performance of the TEG. Thus, a TEG under pulsed heat flux is studied numerically, and the numerical model is verified by experimental results. With the consideration of a defined reference geometry, different heat flux frequencies are applied in order to evaluate the corresponding electrical output by the TEG. In addition, variation of the module performance for various TEG leg …

Hysteresis Heating Of Railroad Bearing Thermoplastic Elastomer Suspension Element, Oscar O. Rodriguez, Arturo A. Fuentes, Constantine Tarawneh, Robert E. Jones

Mechanical Engineering Faculty Publications and Presentations

Thermoplastic elastomers (TPE’s) are increasingly being used in rail service in load damping applications. They are superior to traditional elastomers primarily in their ease of fabrication. Like traditional elastomers they offer benefits including reduction in noise emissions and improved wear resistance in metal components that are in contact with such parts in the railcar suspension system. However, viscoelastic materials, such as the railroad bearing thermoplastic elastomer suspension element (or elastomeric pad), are known to develop self-heating (hysteresis) under cyclic loading, which can lead to undesirable consequences. Quantifying the hysteresis heating of the pad during operation is therefore essential to predict …

Instant Hot Water Heater, Hunter Arnold

All Undergraduate Projects

One of the first steps in the beer brewing process is to heat water to a specific temperature before it is mixed with the malt. The purpose of this project was to make a more compact and efficient heating device for the beer brewing process. The output temperature must be between 170⁰F and 180⁰F. The minimum flow rate should be half a gallon per minute with the maximum flow rate of three gallons per minute. The device will also need to mount to a collapsible beer rack being designed by Andrew Kastning. The device will be primarily compromised of two …

Go With The Flow –Thermoelectric Energy, Shawn Bell

Middle School Lesson Plans

In this unit, students will learn how thermal energy be transferred and transformed. They will carry out investigations to gather evidence to support an explanation about direct conversion of heat into electrical energy. They will develop a model that shows the components of the system and changes in the system being investigated, and they will use evidence from the investigation to construct an explanation for how the energy flows.

Heat Generation In The Railroad Bearing Thermoplastic Elastomer Suspension Element, Oscar O. Rodriguez, Juan Carbone, Arturo A. Fuentes, Robert E. Jones, Constantine Tarawneh

Mechanical Engineering Faculty Publications and Presentations

The main purpose of this ongoing study is to investigate the effect of heat generation within a railroad thermoplastic elastomer suspension element on the thermal behavior of the railroad bearing assembly. Specifically, the purpose of this project is to quantify the heat generated by cyclic loading of the elastomer suspension element as a function of load amplitude, loading frequency, and operating temperature. The contribution of the elastomer pad to the system energy balance is modeled using data from dynamic mechanical analysis (DMA) of the specific materials in use for that part. DMA is a technique that is commonly used to …

Gasoline Confined In Nano-Porous Media, Matthew Giso

Honors Theses

The heat of combustion was determined for gasoline confined in nano-porous media of differing pore size by bomb calorimetry. The heat of combustion of the confined fuels was comparable to that of bulk within the experimental uncertainty. This suggests that all of the confined fuel burns without any flame quenching and no chemical interactions at the interface between pore walls and fuel mitigate combustion.

Cogeneration System Comparison For The Akron Water Treatment Plant, Devin J. Pearcy, Madison R. Morgan

Williams Honors College, Honors Research Projects

Cogeneration is a process of electrical power generation that simultaneously harnesses the heat produced from that electrical generation and uses it to supply heat to a space. The Akron Water Plant was identified as potentially benefitting from this technology for two main reasons. First, they have a large and relatively constant electrical load. Second, they have ownership of a significant amount of natural gas wells at the site.

This report analyzes the economic feasibility of installing a cogeneration plant at the Akron Water Plant (AWP). Data was collected for the plant and its operations, including electricity bills, gas bills, plant …

Looking For Small Changes In Heat Capacity Using A Differential Scanning Calorimeter, Will Linthicum

Honors Theses

One of the major difficulties in development of renewable energy is the lack of an adequate and economical means of energy storage. In the case of concentrated solar power a large mass of thermal fluid is required to store a reasonable amount of energy. This is primarily because the fluids tend to have a low specific heat capacity. Formulating composites of these fluids can enhance their specific heat capacity and avails opportunities to make concentrated solar power more attractive. In most cases, the specific heat capacity of composite materials is a weighted average of the individual component heat capacities. This, …

Antibacterial Activity Of Papaya Leaf Extracts Against Pathogenic Bacteria, Elisa Friska Romasi, Jessica Karina, Adolf Jan Nexson Parhusip

Makara Journal of Technology

It was reported that the extracts of papaya leaves could inhibit the growth of Rhizopus stolonifer. Antibacterial activity of Carica papaya leaf extracts on pathogenic bacteria was observed in this study. Papaya leaves were extracted by using maceration method and three kinds of solvents: ethanol, ethyl acetate, and hexane. Papaya leaf extracts were tested against Bacillus stearothermophilus, Listeria monocytogenes, Pseudomonas sp., and Escherichia coli by agar diffusion method. The objectives of this study were to determine extract ability against pathogenic bacteria, to observe the influence of pH, NaCl, and heat on extracts ability, and to observe extract ability against B. …

Mathematical Analysis Of A Geothermal System, Ivan P. Erceg

ETD Archive

The issue being examined is to design a more economical and efficient therefore superior geothermal system than currently in use in industry. Current geothermal systems are designed and built 300 feet into the ground. After researching ground temperature gradients for Ohio we found out that below 10 feet of depth, the temperature varies by 1 degree Fahrenheit per 100 feet depth. Our goal is to utilize the heat as close to the surface as possible and greatly reduce the need to dig so deeply into the ground. The procedure used to go about designing a superior geothermal system is to …

Numerical Model Of The Transient Effects Of A Heat Of Fusion Reservoir Interacting With Two-Phase Flow, Anne-Marie Bechard Thibodeau

Electronic Theses and Dissertations

The object of this thesis is to develop a numerical model that simulates the transient behavior of a coaxial, thermal energy storage system consisting of a phase changing material ( P O interacting with a two-phase fluid. The purpose of this model would be to have a useful design tool that could be applied when sizing and building iceon- coil, cooling systems (ice-banks). The numerical model is an explicit finite volume approximation applied to the enthalpy method. It solves a two-dimensional, axisymrnetric, heat conduction problem with conjugate forced convection at its inner boundary. Natural convection is neglected in the PCM. …

Laminar Natural Convection In A Discretely Heated Cavity: I—Assessment Of Three-Dimensional Effects, Theodore J. Heindel, S. Ramadhyani, F. P. Incropera

Theodore J. Heindel

Two and three-dimensional calculations have been performed for laminar natural convection induced by a 3 × 3 array of discrete heat sources flush-mounted to one vertical wall of a rectangular cavity whose opposite wall was isothermally cooled. Edge effects predicted by the three-dimensional model yielded local and average Nusselt numbers that exceeded those obtained from the two-dimensional model, as well as average surface temperatures that were smaller than the two-dimensional predictions. For heater aspect ratios Ahtr ≲ 3, average Nusselt numbers increased with decreasing Ahtr . However, for Ahtr ≳ 3, the two and three-dimensional predictions were within 5 percent …

Laminar Natural Convection In A Discretely Heated Cavity: Ii—Comparisons Of Experimental And Theoretical Results, Theodore J. Heindel, F. P. Incropera, S. Ramadhyani

Theodore J. Heindel

Three-dimensional numerical predictions and experimental data have been obtained for natural convection from a 3 × 3 array of discrete heat sources flush-mounted on one vertical wall of a rectangular cavity and cooled by the opposing wall. Predictions performed in a companion paper (Heindel et al., 1995a) revealed that three-dimensional edge effects are significant and that, with increasing Rayleigh number, flow and heat transfer become more uniform across each heater face. The three-dimensional predictions are in excellent agreement with the data of this study, whereas a two-dimensional model of the experimental geometry underpredicts average heat transfer by as much as …

Liquid Immersion Cooling Of A Longitudinal Array Of Discrete Heat Sources In Protruding Substrates: Ii—Forced Convection Boiling, Theodore J. Heindel, S. Ramadhyani, F. P. Incropera

Theodore J. Heindel

Forced convection boiling experiments have been performed for an in-line 1 x 10 array of discrete heat sources, flush mounted to protruding substrates located on the bottom wall of a horizontal flow channel. FC-72, a dielectric fluorocarbon liquid, was used as the heat transfer fluid, and the experiments covered a range of flow velocities, degrees of fluid subcooling, and channel heights. The maximum heater-to-heater surface temperature variation was less than 2.5°C and was insensitive to channel height under conditions of fully developed nucleate boiling. Although the fluid velocity influenced the heat flux for partially developed nucleate boiling, its influence was …

Liquid Immersion Cooling Of A Longitudinal Array Of Discrete Heat Sources In Protruding Substrates: I—Single-Phase Convection, Theodore J. Heindel, F. P. Incropera, S. Ramadhyani

Theodore J. Heindel

Experiments have been performed using water and FC-77 to investigate heat transfer from an in-line 1 x 10 array of discrete heat sources, flush mounted to protruding substrates located on the bottom wall of a horizontal flow channel. The data encompass flow regimes ranging from mixed convection to laminar and turbulent forced convection. Buoyancy-induced secondary flows enhanced heat transfer at downstream heater locations and provided heat transfer coefficients comparable to upstream values. Upstream heating extended enhancement on the downstream heaters to larger Reynolds numbers. Higher Prandtl number fluids also extended heat transfer enhancement to larger Reynolds numbers, while a reduction …

Two-Dimensional Heat Loss From A Building Slab Including Convective Effects In Saturated Soil, William W. Rust Iii

Mechanical & Aerospace Engineering Theses & Dissertations

The heat loss from a building slab was investigated. The continuity equation, Darcy's Law and the energy equation were formulated to include the temperature dependence of viscosity and density of water. The governing equations and appropriate boundary conditions were transformed into dimensionless variables. A finite difference numerical scheme was constructed based on the Gauss-Seidel method by lines and solved iteratively in alternating directions. A correlation between the geometrical characteristics of the domain, the convective surface heating parameters, and the total nondimensional slab heat loss in two dimensions was discovered. Furthermore, the correlation was extended to three-dimensional slabs and produced good …

Effect Of Precursor Heating On Radiating And Chemically Reacting Viscous Flow Around A Jovian Entry Body, Kuo Yen Szema

Mechanical & Aerospace Engineering Theses & Dissertations

The influence of changes in the precursor region flow properties (resulting from absorption of the radiation from the shock layer) on the entire shock layer flow phenomena around a Jovian entry body is investigated under physically realistic conditions. In the precursor region, the flow is considered to be inviscid and the variations in flow properties are determined by employing the small perturbation technique as well as the thin layer approximation. The flow in the shock layer is assumed to be steady, axisymmetric and viscous. The analysis is carried out by considering both the chemical equilibrium and nonequilibrium composition of the …

Heat Transfer In Shock Boundary Layer Interaction Regions, Rex W. Shumway

Theses and Dissertations

The interest in aerodynamic heating problems has been increasing rapidly in the last decade. This interest is no longer concentrated on the heating of simple shapes for which adequate heat transfer theory has been developed« Because of the increasing Mach number ranges of aircraft, the need for information on the aerodynamic heating of various components has become imperative. Only when the magnitude of the problem has been exposed can the design for reducing the severity of local heating be optimized. Definition of these problems is of interest, not only because of the flow phenomena, but because of possible design limitations …

Simultaneous Development Of Velocity And Temperature Profiles In The Annulus With Laminar Flow And Both Walls At Constant Temperatures, Stephen Lothair Ritchie

Theses and Dissertations

Forced convection heat transfer in the entrance region of tubes and ducts has been studied extensively since the pioneering work of Graetz. Most of the published solutions for axial flow heat transfer are based on the idealization of either fully established or uniform velocity profiles with developing temperature.

Analysis And Discussion Of The Effect Of Heat Loss From The "Insulated" Face Of Thin Foil Heat Flux Meters, Mont Johnson Stevens

Theses and Dissertations

The object of this work was to investigate the effect that heat losses from the "insulated" face of thin foil heat flux meters has upon the sensitivity of heat flux meters. In the past it has been characteristic of any analysis done on heat flux meters to assume that the insulation on the back face of the foil was a perfect insulator and thereby neglect the effects of heat losses from this "insulated" face. It is hoped that the information given in this thesis will be of value in determining how the geometric and heat transfer parameters affect the operation …

Design And Fabrication Of An Apparatus To Determine Heat Transfer Coefficients In An Air-Particle Mixture Over A Horizontal Flat Plate At Uniform Temperature, Louis G. Hunter Jr.

Theses and Dissertations

The study of two phase flow, where a finely divided solid is suspended in a fluid medium, has received considerable attention in the last five years due to the increased number of systems in which this phenomena occurs. The two most important areas involving the gas- particle mechanism are nuclear reactor heat exchangers and liquid and solid rockets.