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Non-Intrusive Reduced Order Model Formulation For Inverse Shape Design Including Deforming Meshes And Multiphysics Problems., Kapil Aryal

Mechanical and Aerospace Engineering Dissertations

Despite significant advancements in computer capabilities for numerical simulations, engineers continue to face limitations when dealing with large-scale full-order model(FOM) simulations. These simulations often necessitate repeated solves, such as those encountered in inverse design, real-time solution prediction, error quantification, and solver convergence, among others. To address these challenges, reduced order modeling (ROM) has emerged as a valuable approach. This thesis focuses on the development of an ROM framework that combines Proper Orthogonal Decomposition (POD) with machine learning techniques. This integrated approach is applied to a diverse range of heat transfer and fluid flow inverse design problems. POD constructs optimal sets …

Multi-Scale Modeling Of Selective Laser Sintering: From Manufacturing Process And Microstructure To Mechanical Performance In Semi-Crystalline Thermoplastics, Cameron Zadeh

All Dissertations

Selective laser sintering is an additive manufacturing process that opens many design possibilities but is limited in its reliability and reproducibility. Numerical simulations validated by experimental data yield insights into the process and resulting part properties, allowing users to make more informed decisions. In this dissertation, a model for the process and microstructure is developed and validated, followed by a coupling to mechanical models to predict part performance. Further developments include a new addition of a reaction kinetics model to the process model to describe the interplay between thermal degradation and melt pool properties, and an exploration of the parameter …

Assessment Of Walls With Phase Change Materials Through Synergistic And Performance Measures Using Experimental And Simulated Test Houses, Cory J. Enfield

ELAIA

Current research on living and working spaces continues to strive to identify the most energy-efficient methods for heating and cooling, and many novel technologies have emerged from the research. One of the most promising, and the topic of this quantitative analysis, is the retrofitting of phase change materials (PCMs) into the walls of structures. Research has shown positive results, such as a reduced transfer of heat through walls, when PCMs are retrofitted into wall construction. The present research takes previously gathered data from test houses, built with typical North American framing, and simulates an additional fourteen test houses from the …

Cyclic Superconducting Refrigerators Using Guided Fluxon Propagation, Tathagata Karmakar, Étienne Jussiau, Sreenath K. Manikandan, Andrew N. Jordan

Mathematics, Physics, and Computer Science Faculty Articles and Research

We propose cyclic refrigeration in solid state, employing a gas of magnetic field vortices in a type-II superconductor—also known as fluxons—as the cooling agent. Refrigeration cycles are realized by envisioning a racetrack geometry consisting of both adiabatic and isothermal arms, etched into a type-II superconductor. The guided propagation of fluxons in the racetrack is achieved by applying an external electrical current, in a Corbino geometry, through the sample. A gradient of magnetic field is set across the racetrack allowing one to adiabatically cool down and heat up the fluxons, which subsequently exchange heat with the cold and hot reservoirs, respectively. …

Exploring The Impact Of Vented Packaging Configurations On Airflow Patterns And Cooling Consistency For Muskmelons In A Cold Storage Environment, Nur Wafidah Roslan, Namasivayam Navaranjan, Zohrah Sulaiman, Naseem Uddin

ASEAN Journal on Science and Technology for Development

The cooling effect of different vented packaging designs was investigated for packed muskmelons fruits in a commercial cold storage condition. Computational fluid dynamics (CFD) simulation and experiments were used. The airflow pattern, heat transfer and temperature profiles were predicted from simulation and analysed. The CFD results reveal an uneven and low efficient airflow distribution inside a commercially used vented packaging (Box A). This resulted slow cooling of the fruits in Box A. Two newly designed packaging (Box B and Box C) showed better airflow distribution around the fruits and cooled them faster than Box A. The design of Box C …

Magnetic Field’S Effect On Two-Phase Flow Of Jeffrey And Non-Jeffrey Fluid With Partial Slip And Heat Transfer In An Inclined Medium, Sunday Lot, Waheed Oluwafemi Lawal, Adedapo Chris Loyinmi

Al-Bahir Journal for Engineering and Pure Sciences

In this paper, the effect of magnetic field on two –phase flow of Jeffrey and non-Jeffrey fluids in an inclined medium is investigated. The flow in both medium is assumed to be set in motion by constant pressure gradient. The electrical conductivity in the non-Jeffrey fluid in phase I is considered to be zero, so that the constant magnetic field strength Bo in the transverse direction only affects the Jeffrey fluid in phase II. The equations governed the flow of the fluid were solved using perturbation method. The effect of magnetic field, Jeffrey and thermal slip parameters on the temperature …

Experimental Investigation Of Low Thermal Inertia Thermal Barrier Coatings For Spark Ignition Engines, John Gandolfo

All Theses

The application of thermal barrier coatings (TBCs) in spark ignition (SI) engines has historically been avoided due to the knock penalty associated with higher surface temperatures induced by the ceramic layer. However, advances in low thermal inertia coatings (i.e., temperature swing coatings) that combine low thermal conductivity with low volumetric heat capacity can prevent excessively high surface temperatures during the intake stroke and reduce or avoid knock while improving performance and efficiency. This thesis experimentally evaluates the effectiveness of these low thermal inertia coatings in a single-cylinder research engine representative of modern SI engines.

First, four pistons coated with a …

Thermal Atomization On Superhydrophobic Surfaces Of Varying Temperature Jump Length, Eric D. Lee, Daniel Maynes, Julie Crockett, Brian D. Iverson

Faculty Publications

This paper presents an experimental study of drop impingement and thermal atomization on hydrophobic and superhydrophobic (SH) surfaces. Superhydrophobic surfaces having both microscale and nanoscale geometry are considered. Microscale SH surfaces are coated with a hydrophobic coating and exhibit micropillars and cavities which are classified using the surface solid fraction and center to center pitch. The solid fraction and pitch values explored in this study range from 0.05-1.0 and 8-60 μm respectively. Nanoscale textured surfaces are created by applying a blanket layer of carbon nanotubes. Both types of surfaces are further classified by a temperature jump length (λ …

Simulation Of Seepage And Heat Transfer In 3d Fractured Rock Mass Based On Fracture Continuum Method, Dong-Dong Liu, Li-Xin Wei, Guo-Yuan Xu, Yan-Yong Xiang

Rock and Soil Mechanics

The main challenge of simulating the processes of seepage and heat transfer in fractured rock mass is the heterogeneity of rock mass at various scales. In order to balance the efficiency and accuracy of numerical simulation, the two-dimensional fracture continuum method is extended to a three-dimensional one. Based on the depth-first search algorithm, the effective fractures contributing to the permeability of rock blocks are collected. The block permeability tensor is obtained by considering the contribution of effective fractures and rock matrix. The finite element software COMSOL Multiphysics is integrated with Matlab to generate a three-dimensional fracture continuum model that contains …

Heat Transfer Of Non-Newtonian Drag Reducing Flow In Porous Media, Mohamed Alaa Zahran

Journal of Engineering Research

Forced convection heat transfer for non-Newtonian drag reduction (polyethylene oxide) with heat flux is experimentally studied in a pipe filled with plastic spheres porous media. Along the pipeline, installing pumping stations is expensive; reducing the drag inside the pipe is better. The effect of PEO concentration on the heat transfer properties in the pipe is studied. The experiments are used to demonstrate the effect of changing Reynolds number and PEO concentrations on Nusselt number of the water and polymer solutions for different diameter ratios (d/D) and different concentrations. In the experiments, the test section is a circular pipe filled with …

Heat Transfer Of Non-Newtonian Drag Reducing Flow In Porous Media, Mohamed Alaa Zahran

Journal of Engineering Research

Forced convection heat transfer for non-Newtonian drag reduction (polyethylene oxide) with heat flux is experimentally studied in a pipe filled with plastic spheres porous media. Along the pipeline, installing pumping stations is expensive; reducing the drag inside the pipe is better. The effect of PEO concentration on the heat transfer properties in the pipe is studied. The experiments are used to demonstrate the effect of changing Reynolds number and PEO concentrations on Nusselt number of the water and polymer solutions for different diameter ratios (d/D) and different concentrations. In the experiments, the test section is a circular pipe filled with …

Experimental Investigation Of The Thermal-Hydraulic Performance Of Conically Coiled Tubes Using Al2o3/Water Nanofluid, Mohamed Abdelghany

Journal of Engineering Research

The thermal-hydraulic performance of conically coiled tubes (CCTs) was investigated experimentally under constant heat flux boundary conditions in this study. The effect of several factors, such as the flow Dean number, coil torsion, and varied nanoparticle weight concentrations, on the flow's heat transfer coefficient and pressure drop was studied. Thermo-hydraulic performance was studied at 0.3%, 0.6%, and 0.9% volume concentrations (ϕ) of Al2O3/water nanofluid, a Dean number (De) of 1148–2983, and coil torsions (λ) ranging from 0.02 to 0.052. Results indicated that the heat transfer rates (HTRs) of CCTs increased when the coil torsion was decreased. According to the findings, …

Evaluation Of Digital Twin Approaches For Thermal Modeling And Energy Optimization For Existing Buildings, Jason Bastie Muermann

Theses and Dissertations

Residential, commercial, and industrial building sectors in the United States were responsible for 42% of the nation’s consumption of 100.2 quadrillion BTUs of energy in 2019 [1]. 80% of the nation’s energy is sourced from fossil fuels, including coal, natural gas, and petroleum. Fossil fuels are known contributors to carbon emissions and climate change, making energy reduction vital. Consequently, New Jersey Department of Military and Veterans Affairs (NJDMAVA) is tasked with evaluating energy consumption and efficiency in all New Jersey Army National Guard (NJARNG) facilities, as mandated by TAG Policy Letter 18-5, Executive Order 13990, and the Energy Independence and …

3d Computational Modeling Of Multiphase Phenomena In Boiling Heat Transfer, Winston O. James Iii

Theses

Boiling heat transfer is used in industrial processes, such as heat exchangers, nuclear reactors, and high-powered electronics. There is a need to generate effective heat dissipation techniques to increase the operation limits of these technologies. To enhance heat dissipation with boiling flows, it is important to study boiling phenomena from a fundamental perspective to identify the relation between the fluid and heat transfer behavior near the interface during bubble growth. Boiling simulations have been used as a tool to visualize and quantify the heat transfer mechanisms near the interface. However, challenges exist in modeling bubble growth with a sharp interface …

Measurement Of Conduction, Radiation, And Convection Thermal Energy To Assess Baking Performance In Residential Ovens., Sean Simpson

Electronic Theses and Dissertations

Residential ovens are complicated thermal environments capable of delivering convection, conduction, and radiation heat transfer to food. The amount and mode of heat transfer can change based on the design of the oven cavity, cooling systems, and oven cycle algorithms. Studies have shown that the changes in one heat transfer mode can have an impact on the quality of baked goods. The many variables involved make designing residential ovens a time consuming and costly process. The goal of this study is to adapt thermal energy sensing technology to collect energy data from a residential oven and develop correlations to quality …

Heat Transfer To Rolling Or Sliding Drops On Inclined Heated Superhydrophobic Surfaces, Joseph Merkley Furner

Theses and Dissertations

This thesis examines the time resolved heat transfer to drops rolling or sliding along inclined, subcritical heated non-wetting surfaces. Results were experimentally obtained using IR imaging for a smooth hydrophobic surface and post as well as rib structured superhydrophobic surfaces of varying solid fraction (f_s = 0.06 - 0.5). Tests were performed at varying inclination angle (α = 10, 15, 20, and 25°), drop volume (12, 20, 30, and 40 μL), and surface temperature (T_w = 50, 65, and 80 °C). Rib structured superhydrophobic surfaces were explored for drops moving parallel and perpendicular to the rib structures. The findings indicate …

Advances In Spacecraft Thermal Control, Sandra K. S. Boetcher, Robert C. Consolo Jr.

Publications

Spacecraft thermal management is critical for ensuring mission success, as it affects the performance and longevity of onboard systems. A comprehensive overview of the state of the art in spacecraft thermal control solutions, as well as a design methodology framework for efficient and effective thermal management, is provided. Various thermal control solutions, including coatings, insulation, heat pipes, phase-change materials, conductive materials, thermal devices, actively pumped fluid loops, and radiators, are discussed along with the primary sources of heat loading in space. The need for accurate modeling and analysis of the thermal environment to identify appropriate thermal control solutions and design …

Thermal Atomization Of Impinging Drops On Superheated Superhydrophobic Surfaces, Eric Lee

Theses and Dissertations

Drop impact on a surface has an effect on nearly every industry and this impact may have adverse effects if not controlled. Superhydrophobic (SH) surfaces have been created with the extreme ability to repel water. These surfaces exist in nature but may also be fabricated using modern techniques. This thesis explores heat transfer from these SH surfaces to drops impacting them. This thesis is devoted to increasing the breadth of knowledge of thermal atomization during drop impingement on superheated SH surfaces. When a water drop impinges vertically on a horizontal superheated surface, intense atomization can occur. The atomization is caused …

Direct Spectroscopic Observation Of Cross-Plane Heat Transfer In A Two-Dimensional Van Der Waals Heterostructure, Du Chen, Matthieu Fortin-Deschênes, Yuchen Lou, Huiju Lee, Kenji Watanabe, Takaaki Taniguchi, Fengnian Xia, Peijun Guo, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

Two-dimensional (2D) transition metal chalcogenides (TMDs) have drawn significant attention in recent years due to their extraordinary optical and electronic properties. As heat transfer plays an important role in device performance, various methods such as optothermal Raman spectroscopy and time-domain thermoreflectance have been developed to measure the thermal conductivity and interfacial thermal conductance in 2D van der Waals (vdW) heterostructures. Here, we employ the vibrational-pump-visible-probe (VPVP) spectroscopy to directly visualize the heat transfer process in a heterostructure of multilayer h-BN and monolayer WS2. Following an impulsive vibrational excitation of h-BN in the mid-infrared, we probe the heat transfer …

Thermal Boundary Condition Effects On Local Supercritical Co2 Heat Transfer Trends In Tubes, Nicholas C. Lopes

Doctoral Dissertations and Master's Theses

Supercritical carbon dioxide (sCO2) is a promising heat transfer fluid for the refrigeration and power generation industries due to its unique thermal properties and low environmental impact. To understand it as an alternative to traditional working fluids, the thermophysical and heat transfer phenomena of sCO2 are often studied using simplified geometries (tubes). Focus has been placed on investigating averaged heat transfer trends under an array of flow conditions with either a constant wall heat flux, constant wall temperature, or conjugate thermal boundary condition. Less emphasis has been placed on studying local sCO2 heat transfer developments. Tubular sCO2 numerical models that …

An Experimental-Numerical Study Of Heat Transfer Enhancement In A Minichannel Using Asymmetric Pulsating Flows, Parth S. Kumavat, Sajad Alimohammad, Seamus M. O'Sullivan

Articles

The development of current and next-generation high-performance electronic devices has led to miniaturization in more densely packed spaces. The increasing power levels have resulted in ever-increasing heat flux densities which necessitates the evolution of new liquid-based heat exchange technologies. Implementation of single-phase cooling systems using pulsating flow is viewed as a potential solution to the problems involving high energy density electronics. This work involves a combined experimental and numerical analysis of pulsating flows in a rectangular mini channel undergoing asymmetric sinusoidal flow pulsation formats. The mini channel design includes a heated bottom section approximated as a constant heat flux boundary …

Thermal Efficacy Of Green Walls In Building Structures In The Northeast United States, Nathaniel Wright

Student Showcase

Climate change is one of the most threatening issues that humankind faces in the 21st century and there is indisputable evidence that our planet is experiencing global temperature rise, shrinking of ice sheets and sea level rise, warming oceans, and extreme weather events at an alarming rate. Urbanization drives these changes and creates the Urban Heat Island (UHI) effect. One method to mitigate this issue is urban greening, specifically the construction of green walls which take advantage of unused vertical exteriors of buildings. Despite existing literature on green walls especially in Europe and Asia, green walls must be researched more …

Thermal Analysis Based Design Of Hollow Shaft For Improved Cooling Of Induction Motors, Isabelle Dinh

Electronic Theses and Dissertations

This thesis investigates methods of implanting a forced liquid convection heat recovery system within an induction motor’s shaft to cool the rotor.

The objective is to design a hollow shaft that can meet the target goals of keeping the components under an average temperature of 100℃ under different motor power conditions. Three hollow shaft design cases were studied at steady state conditions to evaluate their heat transfer performance and surface temperature to meet the goals of the study. This includes the design of a counterflow, counterflow with fins, and duct design.

It is found that third design is able to …

A Comprehensive Review Of The Influence Of Heat Exchange Tubes On Hydrodynamic, Heat, And Mass Transfer In Bubble And Slurry Bubble Columns, Dalia S. Makki, Hasan Sh Majdi, Amer A. Abdulrahman, Abbas J. Sultan, Zahraa W. Hasan, Laith S. Sabri, Bashar J. Kadhim, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bubble and slurry bubble column reactors (BCRs/SBCRs) are used for various chemical, biochemical, and petrochemical applications. They have several operational and maintenance advantages, including excellent heat and mass transfer rates, simplicity, and low operating and maintenance cost. Typically, a catalyst is present in addition to biochemical processes where microorganisms are used to produce industrially valuable bio-products. Since most applications involve complicated gas-liquid, gas-liquid-solid, and exothermic processes, the BCR/SBCR must be equipped with heat-exchanging tubes to dissipate heat and control the reactor's overall performance. In this review, past and very recent experimental and numerical investigations on such systems are critically discussed. …

Investigation Of The Effect Of Corundum Layer On The Heat Transfer Of Sic Slab, Sri Elsa Fatmi, Donanta Dhaneswara, Muhammad Anis, Ahmad Ashari

Journal of Materials Exploration and Findings

Aluminum is the most widely used metal in industry. Aluminum smelting is one of the important steps that needs to be carried out to produce products made of aluminum metal with good quality. In the process of smelting aluminum there are several problems that occur, one of which is the growth of corundum in Si C refractories which affects the quality of aluminum melt and the durability of Si C refractories. This research was conducted to see the heat transfer in Si C and the effect of the presence of Corundum on heat transfer. This research was carried out by …

Experimental Simulation Of Nucleating Bubble Behavior In A Microgap With Air Injected Bubbles, Jack Green

Theses

The following study investigates the behavior of bubbles created by air injection under a tapered microgap. It is a continuation of previous work from the Thermal Analysis and Microfluidics Lab at RIT which showed that placing a tapered gap manifold over a heated surface in a pool boiling setup could direct the flow of vapor created by two-phase heat transfer and create a pumping effect to increase its heat transfer performance. This study isolates this phenomenon and examines exactly how bubble motion affects liquid throughput. The results of this study provide insight into the specific parameters which induce this effect …

Hydrogeologic Heterogeneity Identification: Using Inverse Modeling Of Synthetic Borehole Temperatures To Predict Groundwater Flux, Kevin Heintz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat has been effectively used as a groundwater tracer for decades, and high-resolution temperature data can better identify and quantify discrete flow zones. Refinements to the numerical modeling of advective heat transfer in borehole temperature sensing deployments can improve understanding of dynamic hydrogeologic systems. In my thesis, I develop a novel two-dimensional coupled radial groundwater flow and heat transfer numerical model that considers intra-borehole vertical flow. To test the performance of this model, I used finite element analysis to generate synthetic data sets consisting of prescribed variable flow fields and resulting borehole temperatures. I input synthetic temperatures into the two-dimensional …

Measurement Of Low-Speed Impinging Jet Structure Using Temperature Sensitive Paint, Arthur Dean Woodworth

Masters Theses

Temperature sensitive paint (TSP) is used to analyze surface flow structures driven by a jet impinging on a heated steel sheet. Temperature and Nusselt number images are calculated from CCD images of the TSP surface. TSP calibration is discussed. Skin friction data is obtained from the temperature images.

Data is collected for metal and 3D-printed plastic nozzles of varying shape and size at one or two jet airspeeds depending on the nozzle. For the circular nozzles, data is collected for four Reynolds numbers at impinging angles of 90, 70, and 50 degrees. For the elliptical nozzles and the star-shaped nozzle, …

The Deflection And Heat Transfer Analysis Of Injection Mold Cavity With Sla Cooling Channel Insert, Olumide Temidayo Aladesiun

Theses and Dissertations

Fast cooling in injection molding is the critical in the process economy. Among many different cooling channel designs available, conformal cooling offers the best and the most efficient cooling. However, limited awareness, accessibility, complexity, cost, knowledge, and experience limit the use of conformal cooling channels to be used into the mold in a molding process.

Typically, SLM(Selective Laser Melting) method is used to create cavity inserts with conformal cooling channels, however, due to the difficulties listed above, applications of conformal cooling channels are very limited. For an inexpensive alternative SLA (Stereolithography Apparatus) can print cavity inserts with conformal cooling channels. …

Biomass Characterization And Insulation Optimization Studies, Hussein Awad Kurdi Saad

Doctoral Dissertations and Master's Theses

This study indicates how biomass materials can be effectively used as naturally sustainable alternatives to insulation materials. Barley grains and oak leaves, straw, and jute are collected, and crushed into powders/ chopped pieces. The physical characteristics are measured to characterize each powder. The biomass powder reinforced composites are manufactured in varying weight ratios. The density and thermal conductivity of composite materials are measured. The properties of composites compared to those of commercial insulation materials are found to be close to them. Furthermore, genetic algorithms (GA) can be used to achieve multi-objective optimization entailing maximizing insulation (minimizing heat transfer) and simultaneously …