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CFD Study of Ship Hydrodynamics in Calm Water with Shear Current and in Designed Wave Trails

Description: Although the capability of computational fluid dynamics (CFD) in modeling ship hydrodynamics is well explored in many studies, they still have two main limitations. First, those studies ignore the effect of non-uniform shear current which exists in realistic situation. Second, the focus of most studies was laid more on the seakeeping/maneuvering performance and less attention was paid to survivability of ships due to extreme ship response events in waves, which are considered rare events but i… more
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Date: May 2022
Creator: Phan, Khang Minh
Partner: UNT Libraries
open access

Gradient-Index Metamaterial Infrared Detector for Enhanced Photo-Response and Image Quality

Description: An enhanced thermal imaging concept made possible through the development of a gradient-indexed metamaterial infrared detector that offers broadband transmission and reflection in THz waves. This thesis proposes a proof of feasibility for a metamaterial infrared detector containing an anti-reflective coating with various geometrically varying periodic metasurfaces, a gradient-indexed dielectric multilayer for near-perfect longpass filtering, and a gradient index of refraction (GRIN) metalens fo… more
Date: May 2022
Creator: Adams, Kelsa Derek
Partner: UNT Libraries
open access

Impact of Processing Parameters and Forces on Channels Created by Friction Stir Bobbin Tools

Description: In this thesis, friction stir channeling (FSC) and its process parameters influence on geometry, surface quality and productivity are explored. The probe of the friction stir processing (FSP) tool used to perform these tests was a modified submerged bobbin tool made of MP 159 Co-Ni alloy. The body was made from H13 tool steel. To find the optimal channel conditions for a targeted range of process parameters, multiple 6061 aluminum samples were prepared with a U shape guide to test the effects … more
Date: May 2022
Creator: Koonce, James G
Partner: UNT Libraries
open access

Multi-Fidelity Study of Aerodynamics and Aeroacoustics Characteristics of a Quadrotor Biplane Tailsitter

Description: Recent advances in manufacturing and growing concerns on the sustainability of aviation environment have led to a remarkable interest in electrical unmanned aerial systems (UASs) in the past decade. Among various UAS types, the newly designed quadrotor biplane tailsitter class is capable of delivering a wide range of civilian and military tasks, relying on its Vertical Take-Off and Landing (VTOL) capability as well as great maneuverability. Nevertheless, as such UASs employ rotors to generate t… more
Date: May 2022
Creator: Heydari, Morteza
Partner: UNT Libraries
open access

Optimization of Silica Nanocomposite Membranes for Air Dehumidification

Description: This thesis is focused on understanding the correct method to simulate atomistic models to calculate coefficient of diffusion of water through the membrane. It also aims to fix the method previously used in molecular modelling in which the simulation results did not match the experimental results. These membranes will be used in air dehumidification systems. The four types of membranes namely, polyurethane, polyurethane with silica nano particles, polyurethane with silica nano particles and ami… more
Date: May 2022
Creator: Appaji, Tejas
Partner: UNT Libraries
open access

Artificial Neural Network Based Thermal Conductivity Prediction of Propylene Glycol Solutions with Real Time Heat Propagation Approach

Description: Machine learning is fast growing field as it can be applied to solve a large amount of problems. One large subsection of machine learning are artificial neural networks (ANN), these work on pattern recognition and can be trained with data sets of known solutions. The objective of this thesis is to discuss the creation of an ANN capable of classifying differences in propylene glycol concentrations, up to 10%. Utilizing a micro pipette thermal sensor (MTS) it is possible to measure the heat propa… more
Date: August 2022
Creator: Jarrett, Andrew Caleb
Partner: UNT Libraries

Development of an Enclosed Evaporation Chamber Utilizing a Fresnel Lens Solar Concentrator

Description: This thesis project investigates the configuration of an enclosed evaporation chamber with the intention of converting seawater into potable freshwater. The evaporation chamber's sole heat source is provided by a Fresnel lens, located above the chamber, which concentrates sunlight onto a 3-inch diameter focal plate built into the core of the chamber. The design of the evaporation chamber is modeled after a solar still and is coupled with a heat exchanger to boost efficiency of the system. The c… more
Date: August 2022
Creator: Planz, Bridger T
Partner: UNT Libraries
open access

Development of an Interpolation-Free Sharp Interface Immersed Boundary Method for General CFD Simulations

Description: Immersed boundary (IB) methods are attractive due to their ability to simulate flow over complex geometries on a simple Cartesian mesh. Unlike conformal grid formulation, the mesh does not need to conform to the shape and orientation of the boundary. This eliminates the need for complex mesh and/or re-meshing in simulations with moving/morphing boundaries, which can be cumbersome and computationally expensive. However, the imposition of boundary conditions in IB methods is not straightforward … more
Date: August 2022
Creator: Kamau, Kingora
Partner: UNT Libraries
open access

Heat Transfer Analysis of Bio-Printed Tissue Mimicking Material Mixed with Silver Nanoparticles

Description: Novel tissue mimicking materials have been developed for cancer treatment research. In the present research work, the tissue mimicking material is printed using 3D bioprinting technology. The nanoparticles are homogeneously mixed with tissue mimicking materials to enhance the heating capacity. The thermal conductivity of tissue mimicking materials is measured using a micropipette thermal sensor (MTS). Further, the optimal value is identified based on optimization technique and incorporated into… more
Date: August 2022
Creator: Chandrasegaran, Jedeshkeran
Partner: UNT Libraries
open access

Investigation of Structure-Property Effects on Nanoindentation and Small-Scale Mechanical Testing of Irradiated Additively Manufactured Stainless Steels

Description: Additively manufactured (AM) 316L and 17-4PH stainless steel parts, concretely made by laser powder bed fusion (L-PBF), are characterized and micro-mechanical properties of those steels are analyzed. This study also explored and extended to proton irradiation and small-scale mechanical testing of those materials, to investigate how irradiation affects microstructural evolution and thus mechanical properties at the surface level, which could be detrimental in the long term in nuclear application… more
Date: August 2022
Creator: Uddin, Mohammad Jashim
Partner: UNT Libraries
open access

Microgravity Vortex Phase Separator for Liquid Amine CO2 Removal System

Description: The present study investigates vortex phase separator (VPS) technology as a new approach for a liquid amine CO2 removal system. Experimental results obtained using a 99.99% pure CO2 stream and liquid amine with varying concentrations demonstrate the VPS' ability to decrease CO2 volume at its gas outlet. Operating parameters such as CO2 flow rate, relative humidity (RH), and temperature were systematically varied during experimental procedure, as well as working fluid temperature, volume, and fl… more
Date: August 2022
Creator: Sarvadi, Alexander Armstrong
Partner: UNT Libraries
open access

Process Planning for Hybrid Manufacturing with Directed Energy Deposition and Machining Processing

Description: This thesis details the creation and application of a generalized process plan for the hybrid manufacturing of AISI 316L stainless steel, using direct energy deposition (DED) and ball-nose end-mill machining, that includes the inspection and measurement of objects created by that hybrid manufacturing process plan. The proposed process plan progresses through the selection of substrate thickness, single-track, multi-track, and multi-layer depositions, then on to machining processing. A manufact… more
Date: December 2022
Creator: Hughes, Zane Weldon
Partner: UNT Libraries
open access

Tuning Effect on Thermal Radiative Emission of Thermo-Mechano-Optical Gratings and Multilayers

Description: The recipes of optical radiative properties manipulation are their materials chemistry, nano/microscale geometry, and transport properties of quasiparticle carriers such as photons, phonons, and electrons. The important technical element in optical properties is the dielectric function of materials, which is different for metals, dielectrics, 2D materials, and phase transition materials. Graphene has a unique electrical conductivity profile which have metallic nature depending on the frequency,… more
Date: December 2022
Creator: Araki, Ken
Partner: UNT Libraries
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