A Review Of Performance Assessment Of Solar-Driven Absorption Chillers Incorporated With Energy Storage Systems, A. Khalil, Mohamed Abdelgaied, May Abdelsalam

Journal of Engineering Research

Abstract- This study evaluates the performance of a solar

collector absorption chiller combined with Phase Change Material (PCM) energy storage devices. Solar energy is used for energy-efficient cooling, and PCM storage improves

efficiency by capturing surplus thermal energy during

abundant solar radiation and releasing it when insufficient. The research assesses performance measures like

COP, energy storage capacity, and overall system efficiency.

Experimental And Numerical Modelling-Based Optimization Of Additive Manufacturing Processes, Vishnu V. Ganesan

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT

Experimental and Numerical Modeling-Based Optimization of Additive Manufacturing Processes

Vishnu V Ganesan, Ph.D.

The University of Texas at Arlington, 2025

Supervising Professor: Dr. Ankur Jain

Experimental and numerical modeling play a pivotal role in advancing additive manufacturing technologies by enabling a deeper understanding of complex, multi-physics processes that govern part quality, performance, and reliability. These manufacturing techniques—ranging from Powder Bed Fusion (PBF) and Material Extrusion (MEX) to Automated Fiber Placement (AFP)—involve tightly coupled thermal, mechanical, and material phenomena that are challenging to capture through empirical observation alone. Experimental methods offer critical validation and insights into real-world behavior, while numerical …

Deep Neural Network Models For Heatsink Performance Prediction And Optimization In Single Phase Immersion Cooling: Framework For Future Design Tools And Digital Twin Integration, Braxton J. Smith

Mechanical and Aerospace Engineering Theses - Archive

The rapidly rising computational power of modern computing components combined with the advanced packaging techniques being implemented has resulted in exponentially increasing thermal design powers (TDP) from CPUs and GPUs. Traditional air-cooling methods are approaching their effective cooling limits for many of these components, requiring lower supply air temperatures, higher supply air flowrates, and much larger heatsinks to remain feasible. Transitioning from air-cooling to single-phase immersion cooling offers numerous benefits in thermal performance, data-center size reduction, and energy efficiency. To leverage the merits of immersion cooling, the performance of a given heatsink must be predicted and optimized for best performance …

Materials Reliability In Direct-To-Chip Cooling: A Systematic Study Of Aluminum Corrosion In Next-Generation Data Center Coolants, Fnu Harish Gangadhara

Mechanical and Aerospace Engineering Theses - Archive

Data centers are rapidly scaling to support artificial intelligence, cloud platforms, and other high-performance workloads, driving a sharp increase in chip and rack power densities that are now approaching, and in some cases surpassing, 50–100 kW per rack. In response, direct-to-chip liquid cooling has become a key enabling technology for managing these extreme thermal loads, yet the durability of materials in contact with the coolant remains a major reliability concern over system lifetimes. Copper has traditionally been used for cold plates and cooling-loop components, but its relatively high cost, mass, and supply-chain uncertainty are motivating a shift toward aluminum as …

From Spark To Wildfire: Predicting Wildfire Origins And The Efficacy Of “Fire Safe” Cigarettes In California Grasslands, Trevor Blackwell Haltermann

Cal Poly Humboldt theses and projects

As wildfires in North America increase in size and frequency, the societal impacts become greater as well. With greater risk and high fire suppression costs it is pertinent to improve fire investigation methods and limit the potential for human caused ignitions. Two distinct studies were carried out to assess the accuracy of fire pattern indicators and the efficacy of “fire safe” cigarette technology in lowland grass fuel types in California. The first study utilized 24 experimental small-scale fires within a wind tunnel to examine the accuracy of microscale fire pattern indicators and the factors that influence the accuracy of predictions …

Optimizing Material Selection And Operational Conditions For Xhv Systems: Lessons From Aisi 1020 And 316l Comparative Studies, Aiman H. Al-Allaq, Md Abdullah Mamun, Matt Poelker, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

In this study, AISI 1020 low-carbon steel was investigated as a cost-effective alternative to SS316L stainless steel for reaching extreme high vacuum (XHV) conditions. After being baked at 400°C, a vacuum chamber made of low-carbon steel material exhibited an outgassing rate approximately 2000 times smaller than a similar chamber made of stainless steel. Its activation energy for hydrogen diffusion (27 kJ/mol) is less than half that of stainless steel (60.3 kJ/mol), indicating more efficient hydrogen removal during bakeout. MolFlow+ simulations supported the experimental data and demonstrated the importance of system geometry optimization and minimizing stainless steel content for achieving optimal …

Growth Kinetics And Stability Of Metal Halide Perovskite Nanocrystals: Influence Of Stirring Speed And Water Exposure, You-Lin Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Cesium lead bromide (CsPbBr₃) perovskite nanocrystals (NCs) have garnered significant interest due to their exceptional optoelectronic properties, including high photoluminescence quantum yield, tunable bandgap, and excellent carrier dynamics. These attributes make them promising candidates for applications in light-emitting diodes, photovoltaics, and sensing technologies. However, optimizing their synthesis and improving their environmental stability remain critical challenges. This dissertation explores the growth kinetics of CsPbBr₃ NCs, focusing on the effects of stirring speed and water exposure on their structural and optical properties.

The synthesis of CsPbBr₃ NCs was performed using both mechanochemical (MC) and antisolvent methods, enabling an …

Microwave-Assisted Reduction Of Critical Metal Oxides From E-Waste Mixture, Kurundu Shavinka Jayasekera

Graduate Theses, Dissertations, and Problem Reports (ETD)

The efficient recovery of critical metals such as tantalum (Ta), manganese (Mn), gallium (Ga), and indium (In) from electronic waste (e-waste) is essential for resource sustainability and environmental protection. This research uses microwave-assisted treatment to investigate the carbothermal reduction of these four specific metals from their oxides in a simulated e-waste mixture, with carbon black serving as both a microwave coupling and reduction agent. Microwave processing is used specifically because it offers a rapid and energy-efficient alternative to conventional thermal methods, with the benefits of intrinsic heating and selective heating of materials. The first experiments centered on understanding the effects …

Multiphysics Modeling Of Solid Oxide Fuel Cells For Gradient Minimization And Inductive Loop Analysis In Impedance Spectroscopy Using Machine Learning-Based Microstructural Property Estimation, Muhammad Usman Khan

College of Graduate Studies: Theses & Dissertations

Solid oxide fuel cells have significant advantages in renewable energy utilization due to their high efficiency, fuel flexibility, and low emissions. However, despite the numerous efforts of technology, thermal and current density gradients and impedance behavior fluctuations are still causing performance degradation. A combined computational framework that integrates machine learning and three-dimensional Multiphysics modeling is needed to investigate and optimize the performance of solid oxide fuel cells. A machine learning model, trained on synthetic microstructure data by percolation analysis, is used to predict important microstructural parameters like triple phase boundary density and geometric tortuosity. These are then employed in a …

Thermal Management For Optimal Performance Of Polymer Electrolyte Membrane Unitized Regenerative Fuel Cells, Mythy Tran, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

Hydrogen is an excellent carrier for energy storage and can be produced from various green and renewable sources. However, the cost of producing hydrogen and converting it to useful energy is much higher than fossil fuel and traditional energy generation and storage systems. Unitized regenerative fuel cells (URFC) maximize utilization of high-cost cells and their components, thus, lowering system capital cost. Improving the URFC efficiency is an effective way to lower its operating cost. This study evaluates utilization of waste heat during operation and recovery strategy to improve system efficiency of Proton Exchange Membrane (PEM) URFC. A COMSOL Multiphysics 3-D …

A Novel Intelligent Thermal Feedback Framework For Electric Motor Protection In Embedded Robotic Systems, Mohamed Shili, Salah Hammedi, Hicham Chaoui, Khaled Nouri

Electrical & Computer Engineering Faculty Publications

As robotic systems advance in autonomy and sophistication while being used in uncertain environments, the challenge of building reliable and robust electric motors that are embedded into robotic systems has never been a more important engineering problem. Thermal distress caused by extended operation or excessive loading can negatively affect a motor’s performance and efficiency and lead to catastrophic hardware failure. This paper proposes a novel intelligent control framework that includes real-time thermal feedback for hybrid electric motors that are embedded into robotic systems. The framework relies on adaptive control techniques and lightweight machine learning techniques to estimate internal motor temperatures …

Rapid Convective Quench Apparatus Design, Samuel Fenik, Tyler Horvath, Dane Manias, Nicholas Michel

Williams Honors College, Honors Research Projects

In this project, we will research, model, and simulate the heat transfer of a red-hot steel plate undergoing a rapid quenching process by high pressure water jets. Our objective is to quench the steel plate in such a way so that the steam formed from the initial water contact does not inhibit the oncoming water from making proper contact with the plate. After sufficient research has been done, we will design an apparatus which will perform the optimal quenching method and record temperature data with the goal of obtaining the heat transfer coefficient. The purpose of our project is to …

Akronauts Turbopump Research Project, Gerald Drabeck Iii, Michael Mccalla, Joshua Skelton

Williams Honors College, Honors Research Projects

The idea of this project is to design a turbo pump template capable of fitting into future Akronauts rocket designs. This allows the rockets to travel higher due to the reduced net weight. Many methods were used to verify the rigidity and feasibility of the design, such as Finite Element Analysis and fluid dynamics simulations.

Design And Development Of A Rapid Tensile Quench Rig, Tyler Jewell, Justin Naylor

Williams Honors College, Honors Research Projects

This report outlines the design process and implantation of a tensile quenching rig that incorporated forced convection and a frequency generator. When any metal is quenched, a vapor barrier forms around it. When this happens, it limits the heat flux that may occur until the barrier turns into just nucleate boiling. The vapor barrier acts as an insulator and causes the heat flux to fluctuate, causing uneven hardening which would limit the use of some materials. To combat this effect, we are trying to use forced convection, and something new, which is adding high frequency waves into the quenching process. …

Numerical Modelling And Co-Optimization Of Gasoline Fuels For Gasoline Compression Ignition Using Multi Component Approach, Ashwin Karthik Purushothaman

Dissertations, Master's Theses and Master's Reports

Future mobility is expected to rely on a broad spectrum of powertrain technologies, including battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), fuel cell electric vehicles (FCEVs) and traditional internal combustion engine (ICE) vehicles. Despite the shift toward electrification, internal combustion engines are projected to remain a key component of future powertrains, either as the primary power source or as range extenders to generate electricity in hybrid systems. As such, significant research efforts continue to focus on enhancing the efficiency and reducing the emissions of ICEs to meet increasingly stringent regulatory and environmental targets. Gasoline compression ignition (GCI) has been …

Design And Lab Implementation Of An Air Source Transcritical Co2 Heat Pump, Geoffrey Turbeville

Dissertations and Theses

A laboratory-scale air-source transcritical CO2 heat pump (TCHP) was developed to evaluate the performance of low-global-warming-potential (GWP) refrigerants for cold climate applications. A custom climate chamber was also constructed to simulate winter weather conditions typical of the northeastern United States. Both the TCHP and the chamber were fully instrumented to collect temperature, pressure, and mass flow data, which were used to calculate the co- efficient of performance (COP) in accordance with ASHRAE standard refrigerant enthalpy methods. Prior to testing the CO2 system, the experimental setup was benchmarked using a commercially available R410A heat pump manufactured by LG.

The climate chamber …

Cfd Modeling And Simulation Of Natural Circulation In Helium- Cooled Very High Temperature Reactors, Mohammad Sakib U. Abrar

Dissertations and Theses

This thesis investigates the thermal-hydraulic behavior of natural circulation in helium-cooled Very High Temperature Reactor (VHTR) systems, focusing on the performance and validation of passive safety features under Pressurized or Depressurized Loss of Forced Cooling (P-LOFC or D-LOFC) events. An experimental facility inspired by the General Atomics 350 MWt Modular High Temperature Gas-Cooled Reactor (MHTGR) was developed at The City College of New York. The setup consists of a plenum-to-plenum flow loop with four riser and four downcomer tubes, each equipped with heating coils, thermocouples, and pressure sensors. Natural circulation is driven by density gradients induced by asymmetric heating of …

Fundamental And Applied Investigation Of Ammonia Combustion: Characteristics And Emissions At Relevant Ic Engine Conditions, Luis Fernando Alvarez Correa

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ammonia (NH3) is regarded as a promising fuel for future carbon-free power and propulsion systems due to its high hydrogen content, ease of storage, and existing infrastructure. Despite these advantages, NH3 exhibits inherently poor combustion characteristics, including low laminar burning velocity, high ignition energy, narrow flammability limits, and sluggish chemical kinetics. These limitations were solved in prior research by blending NH3 with hydrogen (H2) or hydrocarbons, which improved reactivity but introduced trade-offs such as increased complexity, safety concerns, or carbon emissions. Consequently, there remains a significant lack of fundamental and applied research on neat NH3 combustion, particularly under engine-relevant conditions …

Advanced Air Preheater Sealing Systems For Enhanced Efficiency And Reliability In Thermal Power Plants, Pavan Kumar Ravulaparthy

Theses and Dissertations

Global electricity generation still relies heavily on thermal power plants, which consume vast amounts of fuel and emit significant amounts of carbon dioxide. A major but often overlooked source of inefficiency in these plants lies within the rotary regenerative air preheater (RAPH), a critical heat-exchange component where air leakage can exceed 20% in aging units. This leakage increases fuel consumption, parasitic fan power, and CO₂ emissions, while degrading boiler reliability.

This research introduces advanced adaptive sealing systems designed to mitigate these losses by dynamically compensating for rotor eccentricity, thermal distortion, and wear under harsh operating conditions. Brush seals, composed of …

An Investigative Study Of Thermal Fluid Properties When Introducing Metallic Nanoparticles Through A Heat Exchanging System, Levi P. Mckinney

College of Graduate Studies: Theses & Dissertations

Heat-exchanging systems are essential in applications ranging from automobiles to air-conditioning units, and ongoing improvements aim to enhance efficiency while reducing system size. Conventional coolant upgrades often rely on ethylene glycol, which increases thermal stability and lowers freezing point but reduces water’s inherent heat-transfer capability. Advances in nanotechnology provide an alternative approach: suspending nanoparticles in base fluids can significantly modify thermal properties, with some formulations exhibiting conductivity increases of up to 60%. This thesis examines the thermal and tribological performance of three working fluids—distilled water, a 50:50 water–ethylene glycol mixture, and the same mixture enhanced with Al₂O₃ nanoparticles. Distilled water …