Engineering Commons^™

Numerical Modeling Of Infrared Thermography Techniques Via Ansys, Hayder Abdulnabi Thajeel

Masters Theses

"Several inspection techniques have been developed over years. Recently, infrared thermography (IRT) technology has become a widely accepted as a nondestructive inspection (NDI) technique for different fields and various applications as well. Infrared thermography stands as one of the most an attractive and a successful NDI technique that has ability to detect the object's surface/subsurface defects remotely based on observing and measuring the surface's emitted infrared heat radiation by using an infrared camera. The finite element modeling FEM ANSYS was successfully used for the modelling of several IRT techniques; such as Pulsed Thermography (PT) and Lock-in Thermography (LT) that can …

Thermal Transport To Sessile Water Droplets On Heated Superhydrophobic Surfaces Of Varying Cavity Fraction, Robb C. Hays

Theses and Dissertations

The hydrophobicity of a surface is defined as the degree to which it repels water molecules, and the internal contact angle that the droplet makes with the surface is a measure of the hydrophobicity. Contact angles less than 90° occur on hydrophilic surfaces, while contact angles greater than 90° occur on hydrophobic surfaces. If a surface's contact angle is greater than 120° the surface is commonly defined as superhydrophobic (SH). Superhydrophobicity is accomplished through a combination of microscale surface roughness and water repellant surface chemistry. The roughness creates cavities, or pockets, of vapor underneath the droplet which act to increase …

Computational Fluid Dynamics Validation Of Buoyant Turbulent Flow Heat Transfer, Jared M. Iverson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Computational fluid dynamics (CFD) is commonly used to visualize and understand complicated fluid flow and heat transfer in many industries. It is imperative to validate the CFD computer models in order to avoid costly design choices where experimentation cannot be used to ratify the predictions of computer models. Assessments of CFD computer models in the literature conclude that significant errors occur in computer model predictions of fluid flow influenced by buoyancy forces.

The Experimental Fluid Dynamics Laboratory at Utah State University constructed a wind tunnel with which to perform experiments on buoyancy induced fluid flow. The experiments measured the heat …

Computational Analysis To Enhance Laminar Flow Convective Heat Transfer Rate In An Enclosure Using Aerosol Nanofluids, Andrew Hudson

Electronic Theses and Dissertations

The current research intends to provide a starting point to effectively model aerosol heat transfer in a narrow, enclosed body. This research can lead to future modeling of nano fluids including their heat transfer characteristics and erosion effects on the walls of an enclosure. The model was developed using ICEM CFD for the mesh and FLUENT for the fluid flow modeling. Six different aspect ratio enclosures were developed to study the effects of varying aspect ratio. The natural convection of air was developed first to establish the appropriateness of the models being used. A mesh check was performed using one …

Determination Of Heat Transfer In Under-Floor Plenums In Buildings With Under-Floor Air Distribution Systems, Yan Xue

Open Access Theses

Under-Floor Air Distribution (UFAD) systems have potential advantages of energy saving and indoor air quality improvement over conventional well-mixed systems. As a ventilation strategy for buildings, a UFAD system provides conditioned air to occupied rooms through diffusers in raised floors and the air is exhausted through return grilles at the ceiling level.

Many previous researches have focused on the energy saving and air quality improvement by UFAD systems because of their high supply air temperature and room air stratification. However, few of them paid attention to the effects of the heat transfer through floor slabs on the energy performance of …

Pressure And Heat Flux Effects On The Heat Transfer Characteristics Of Liquid Methane, Chance Paul Garcia

Open Access Theses & Dissertations

The heat transfer effects on liquid methane are investigated with the use of a carbo-thermal rig at the Center for Space Exploration Technology Research (cSETR) located at the University of Texas at El Paso (UTEP). The cSETR carbo-thermal rig design approach is presented along with the design of a methane condensing mobile unit (MCMU) to supply the laboratory and rig with liquid methane. The proposed research will generate useful insight in to heat transfer coefficient behavior, non-dimensional correlations, different flow conditions, varied inlet conditions, and varied heat flux for a subscale test article applicable to a regenerative cooled rocket engine …

Boiling And Evaporation On Micro/Nanoengineered Surfaces, Xianming Dai

Theses and Dissertations

Two-phase transport is widely used in energy conversion and storage, energy efficiency and thermal management. Surface roughness and interfacial wettability are two major impact factors for two-phase transport. Micro/nanostructures play important roles in varying the surface roughness and improving interfacial wettability. In this doctoral study, five types of micro/nanoengineered surfaces were developed to systematically study the impacts of interfacial wettability and flow structures on nucleate boiling and capillary evaporation. These surfaces include: 1) superhydrophilic atomic layer deposition (ALD) coatings; 2) partially hydrophobic and partially hydrophilic composite interfaces; 3) micromembrane-enhanced hybrid wicks; 4) superhydrophilic micromembrane-enhnaced hybrid wicks, and 5) functionalized carbon …

Steady And Unsteady Thermo-Strucural Simulation Of Thermally Actuated Micro- And Nano-Structures, Elham Maghsoudi

LSU Doctoral Dissertations

This dissertation provides a thermo-structural simulation for nano-scale and micro-scale structures with pinned and fixed boundary conditions which are either thermally positioned, buckled, or actuated. The study begins with simulating a pinned-pinned beam in micro-scale and nano-scale. The steady state thermo-structural equation is solved numerically using an implicit Finite Difference method implemented in Matlab to obtain the thermal positioning response, which is the thermally steady state center displacement, by adding a constant, time-independent heat flux to the structure. The results show the steady state thermal displacement of the system is a function of the geometry, pressure, material properties, and constant …

Design, Manufacturing, And Assembly Of A Flexible Thermoelectric Device, Christopher Anthony Martinez

USF Tampa Graduate Theses and Dissertations

This thesis documents the design, manufacturing, and assembly of a flexible thermoelectric device. Such a device has immediate use in haptics, medical, and athletic applications. The governing theory behind the device is explained and a one dimensional heat transfer model is developed to estimate performance. This model and consideration for the manufacturing and assembly possibilities are the drivers behind the decisions made in design choices. Once the design was finalized, manufacturing methods for the various components were explored. The system was created by etching copper patterns on a copper/polyimide laminate and screen printing solder paste onto the circuits. Thermoelectric elements …