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Prediction Of Temperature Difference Across Thermoacoustic Stack Through Artificial Neural Network Technique, Anas A. Rahman, Xiaoqing Zhang 2022 Future University in Egypt (FUE)

Prediction Of Temperature Difference Across Thermoacoustic Stack Through Artificial Neural Network Technique, Anas A. Rahman, Xiaoqing Zhang

Future Engineering Journal

This study involved the application of artificial neural network (ANN) as a new approach for thermoacoustic refrigerators to predict the temperature difference across the stack under some operating conditions. One ANN model for a standing wave thermoacoustic refrigerator, had been developed based on the experimental data from other literature. Temperature difference across the stack was chosen as a response to the input parameters, mean pressure and frequency in the proposed ANN model. A multi-layer feed-forward neural network with a back propagation algorithm had been proposed for predicting the temperature difference across the stack of the thermoacoustic refrigerator. This proposed ANN ...


Film Cooling In Gas Turbine And Nozzle, Manideep Uduta Engineer-Graduate Aerospace, Vaibhav Naiknavre Engineer-Graduate Aerospace 2022 Sandip University, Maharashtra, Nashik, INDIA

Film Cooling In Gas Turbine And Nozzle, Manideep Uduta Engineer-Graduate Aerospace, Vaibhav Naiknavre Engineer-Graduate Aerospace

Graduate Research in Engineering and Technology (GRET)

A gas turbine is a rotating engine that generates its power through the flow of combustion gases. With either an axial or centrifugal compressor, air from the surrounding environment is drawn into the engine intake, where it is compressed and heated before being sent to combustion chamber. Every gas turbine engine has a nozzle as a standard part. Among its many responsibilities include propelling the engine forward, returning exhaust gases to the free stream, and regulating mass flow through the engine. When the power turbine's exhaust exits, the nozzle is directly in the direction of the fumes. Simply put ...


Engine Use In Hybrid Rocket - A Review, Shantanu. U. Bayaskar Er., Vaibhav Arya Graduate Engineer, Shiva Prasad U Prof. 2022 Sandip University

Engine Use In Hybrid Rocket - A Review, Shantanu. U. Bayaskar Er., Vaibhav Arya Graduate Engineer, Shiva Prasad U Prof.

Graduate Research in Engineering and Technology (GRET)

Despite all the other rocket motors on the market such as solid and liquid. A historically failed motor was in the market which was handicapped in performance but now with technological development in the previous years, hybrid rocket motor is the most influential talk in the market.

Deeper in the paper we will discuss the hybrid motor focusing on the fuel used in Hybrid rocket engines and the performance depending on the design. Furthermore, this review paper will help us to study the different materials for the betterment of the engine performance. We will also be focusing on the methods ...


Mmteg Heatsink Design, Peyton Nienaber, Kadin Feldis, Alec Savoye, Jack Waeschle 2022 California Polytechnic State University, San Luis Obispo

Mmteg Heatsink Design, Peyton Nienaber, Kadin Feldis, Alec Savoye, Jack Waeschle

Mechanical Engineering

In this document, Cal Poly Senior Design Team F16 presents a summary of its work developing a suitable heatsink for Gas Technology Institute’s Methane Mitigation Thermoelectric Generator. After several months of iterating between experimental testing and simulated heat transfer, a suitable prototype was selected for use in further refining simulation parameters. This was called the structural prototype and it allowed Team F16 to confirm several remaining unknowns relating to component thermal conductivity. All documentation of this process can be found in Preliminary, Critical, and Interim Design Review documents (PDR, CDR, IDR), included in this report. Having a realistic model ...


Insulated Solar Electric Cooker With Phase Change Materials, WeiJun Zhao, Jake Lung, Owen Chu, Sarah Melzer 2022 California Polytechnic State University, San Luis Obispo

Insulated Solar Electric Cooker With Phase Change Materials, Weijun Zhao, Jake Lung, Owen Chu, Sarah Melzer

Mechanical Engineering

This Senior Project Report documents the development and design process of the Insulated Solar Electric Cooker with a Phase Change Material (ISEC w/ PCM). In this project, we developed a PCM assembly that can be integrated into an existing ISEC system which utilizes two 100 W solar panels. This report details the use of a nitrate salt solution of 60% NaNO3 and 40% KNO3 and demonstrates its potential as a viable form of thermal storage solution for cooking. We found that only 1kg of PCM is able to retain its heat for around 5 hours after power removal and believe ...


Solid Thermal Storage As An Energy Storage Device In Insulated Solar Electric Cookers: Thermal Modeling And Experiment, Michael Antonio Fernandez 2022 California Polytechnic State University, San Luis Obispo

Solid Thermal Storage As An Energy Storage Device In Insulated Solar Electric Cookers: Thermal Modeling And Experiment, Michael Antonio Fernandez

Physics

The use of solid thermal storage (STS) as an energy storage device in insulated solar electric cookers (ISEC) was explored using a thermal simulation before retrofitting an existing cooker without energy storage and testing it under several conditions. STS sizing, material selection, and geometry were examined from both theoretical and practical perspectives and re-examined following experimental results. Characterization of the system’s thermal interfaces and methods to improve their thermal conductivities were investigated resulting in several performance enhancements to the system.


Lattice Boltzmann-Based Sharp-Interface Schemes For Conjugate Heat And Mass Transfer And Diffuse-Interface Schemes For Dendritic Growth Modeling, Nanqiao Wang 2022 Mississippi State University

Lattice Boltzmann-Based Sharp-Interface Schemes For Conjugate Heat And Mass Transfer And Diffuse-Interface Schemes For Dendritic Growth Modeling, Nanqiao Wang

Theses and Dissertations

Analyses of heat and mass transfer between different materials and phases are essential in numerous fundamental scientific problems and practical engineering applications, such as thermal and chemical transport in porous media, design of heat exchangers, dendritic growth during solidification, and thermal/mechanical analysis of additive manufacturing processes. In the numerical simulation, interface treatment can be further divided into sharp interface schemes and diffuse interface schemes according to the morphological features of the interface. This work focuses on the following subjects through computational studies: (1) critical evaluation of the various sharp interface schemes in the literature for conjugate heat and mass ...


Structural Sizing Of Post-Buckled Thermally Stressed Stiffened Panels, Walid Arsalane 2022 Mississippi State University

Structural Sizing Of Post-Buckled Thermally Stressed Stiffened Panels, Walid Arsalane

Theses and Dissertations

Design of thermoelastic structures can be highly counterintuitive due to design-dependent loading and impact of geometric nonlinearity on the structural response. Thermal loading generates in-plane stresses in a restrained panel, but the presence of geometric nonlinearity creates an extension-bending coupling that results in considerable transverse displacement and variation in stiffness characteristics, and these affects are enhanced in post-bucking regimes. Herein a methodology for structural sizing of thermally stressed post-buckled stiffened panels is proposed and applied for optimization of the blade and hat stiffeners using a gradient-based optimizer. The stiffened panels are subjected to uniform thermal loading and optimized for minimum ...


Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock 2022 University of Maine

Development And Evaluation Of Modeling Approaches For Extrusion-Based Additive Manufacturing Of Thermoplastics, Christopher C. Bock

Electronic Theses and Dissertations

This work focuses on evaluating different modeling approaches and model parameters for thermoplastic AM, with the goal of informing more efficient and effective modeling approaches. First, different modeling approaches were tested and compared to experiments. From this it was found that all three of the modeling approaches provide comparable results and provide similar results to experiments. Then one of the modeling approaches was tested on large scale geometries, and it was found that the model results matched experiments closely. Then the effect of different material properties was evaluated, this was done by performing a fractional factorial design of experiments where ...


Generative Designs Of Lightweight Air-Cooled Heat Exchangers, Connor Miller 2022 University of Arkansas, Fayetteville

Generative Designs Of Lightweight Air-Cooled Heat Exchangers, Connor Miller

Mechanical Engineering Undergraduate Honors Theses

The development of high-performance air-cooled heat exchangers is required to permit the rapid growth of vehicle and aircraft electrification. In electric vehicles and airliners, the motors and power electronics are integrated into a compact space, leading to unprecedently high power density. To achieve higher overall thermal efficiency, the heat exchangers must be extremely light while maintaining their heat transfer performance and mechanical robustness. Recently advances in 3D metal printing, e.g., direct metal laser sintering, and selective laser melting, have enabled the manufacturing of high-performance robust heat exchangers by eliminating thermal boundary resistance and ensuring a uniform thermal expansion coefficient ...


Triggering Thermal Runaway In Lithium-Ion Batteries, Chris John 2022 University of Connecticut

Triggering Thermal Runaway In Lithium-Ion Batteries, Chris John

Honors Scholar Theses

The proliferation of lithium-ion batteries enables electric devices such as cell phones to electric vehicles to become a reality. A latent danger, however, exists in these batteries. Mechanical, thermal, or electrical damage can initiate a phenomenon known as thermal runaway (TR). This damage causes internal short circuits within the battery, releasing heat and triggering exothermic decomposition reactions. The battery will catch fire if rapid cooling is not present. While experimental designs exist for evaluating TR, significant safety hazards and impracticality may impede testing efforts. Finite element analysis, therefore, becomes a vital tool in modeling TR and mitigation techniques. However, there ...


Fluid Structure Interactions Within A Common Rail Diesel Injector., Russell Prater 2022 University of Louisville

Fluid Structure Interactions Within A Common Rail Diesel Injector., Russell Prater

Electronic Theses and Dissertations

The internal flow of a high-pressure diesel injector is simulated numerically to investigate the complex transient flow structures and the unsteady forces imparted to the injector needle that result from the asymmetric flow fields developed during operation. The gas-liquid two phase flow is simulated using a mixture model with the cavitation numerically modeled using the Zwart-Gerber-Belamri model. Both the k-ε model and the detached eddy simulation (DES) model are used, and the numerical results are compared. This dissertation looks at the internal flow of a generic injector at different lifts and characterizes the flow parameters at high lift and low ...


Nucleate Boiling Under Different Gravity Values: Numerical Simulations & Data-Driven Techniques., Sandipan Banerjee 2022 University of Louisville

Nucleate Boiling Under Different Gravity Values: Numerical Simulations & Data-Driven Techniques., Sandipan Banerjee

Electronic Theses and Dissertations

Nucleate boiling is important in nuclear applications and cooling applications under earth gravity conditions. Under reduced gravity or microgravity environment, it is significant too, especially in space exploration applications. Although multiple studies have been performed on nucleate boiling, the effect of gravity on nucleate boiling is not well understood. This dissertation primarily deals with numerical simulations of nucleate boiling using an adaptive Moment-of-Fluid (MoF) method for a single vapor bubble (water vapor or Perfluoro-n-hexane) in saturated liquid for different gravity levels. Results concerning the growth rate of the bubble, specifically the departure diameter and departure time have been provided. The ...


Novel Thermal Coating For High-Speed Airplanes, Abinash Satapathy, Lakshay Battu, Liam Watson, Nazanin Rajabi 2022 Kennesaw State University

Novel Thermal Coating For High-Speed Airplanes, Abinash Satapathy, Lakshay Battu, Liam Watson, Nazanin Rajabi

Symposium of Student Scholars

In comparison to various other materials, Carbon Fiber, specifically Carbon Fiber Reinforced Polymers (CFRP), is pre-eminent amongst other materials for use on aeronautical systems. Due to its high specific strength (strength-to-weight ratio), CFRP is prominent for carrying heavy loads while maintaining a lightweight build. However, when influenced by heat resulting from air resistance, CFRP is known to undergo serious degradation that would significantly decrease the effectiveness of the polymers. To prevent this degradation and maintain the strength of the CFRP, thermal protective layers (TPLs) are designed to shield the CFRP from heat exposure. This research is focused on the examination ...


Experimental And Numerical Investigation Of Lauric Acid Melting At Suboptimal Inclines, Casey J. Troxler 2022 Embry-Riddle Aeronautical University

Experimental And Numerical Investigation Of Lauric Acid Melting At Suboptimal Inclines, Casey J. Troxler

PhD Dissertations and Master's Theses

Validation experiments are the baseline for completing numerical studies for engineering design. Applications of the enthalpy-porosity model have expanded in research with the growth of new technologies such as metal additive manufacturing or the renewed interest in thermal energy storage for supplementing renewable energy. A simplified experiment examining the melting behavior of lauric acid from an isothermal surface has become a common case for validating the performance of numerical models. Several studies of this rectangular experiment have been repeatedly used as model validation in a variety of problem conditions.

The first part of this study presents experimental data for the ...


Computational Study Of Internal Flow, Near Nozzle And External Spray Of A Gdi Injector Under Flash-Boiling Conditions, Chinmoy krushna Mohapatra 2022 University of Massachusetts Amherst

Computational Study Of Internal Flow, Near Nozzle And External Spray Of A Gdi Injector Under Flash-Boiling Conditions, Chinmoy Krushna Mohapatra

Doctoral Dissertations

The early and late portions of transient fuel injection have proven to be a rich area
of research, especially since the end of injection can cause a disproportionate amount
of emissions in direct injection internal combustion engines. While simulating the
internal flow of fuel injectors, valve opening and closing events are the perennial
challenges. A typical adaptive-mesh CFD simulation is extremely computationally
expensive, as the small gap between the needle valve and the seat requires very
small cells to be resolved properly. Capturing complete closure usually involves a
topological change in the computational domain. Furthermore, Internal Combustion
Engines(ICE) operating ...


Data On The Validation To Determine The Material Thermal Properties Estimation Via A One-Dimensional Transient Convection Model, Lauren B. Tomanek, Daniel S. Stutts 2022 Missouri University of Science and Technology

Data On The Validation To Determine The Material Thermal Properties Estimation Via A One-Dimensional Transient Convection Model, Lauren B. Tomanek, Daniel S. Stutts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

These data were acquired to estimate the parameters of a closed form solution of a one-dimensional transient convection heat diffusion PDE. The purpose was to demonstrate that the model could be used to determine the thermal conductivity. The system was tested for a wide range of thermal conductivity, 15-400 W/mK, in order to verify that the method was applicable for various materials. The data reported here refer to the study in the research articles, “Material Thermal Properties Estimation Via a One-Dimensional Transient Convection Model” and “Influence of porosity on the thermal, electrical, and mechanical performance of selective laser melted ...


Detailed Velocity And Heat Transfer Measurements In An Advanced Gas Turbine Vane Insert Using Magnetic Resonance Velocimetry And Infrared Thermometry, Michael Benson, David Bindon CDT'19, Mattias Cooper CDT'19, F. Todd Davidson, Benjamin Duhaime CDT'19, David Helmer, Robert Woodings CDT'19, Bret P. Van Poppel, Christopher J. Elkins, John P. Clark 2022 United States Military Academy

Detailed Velocity And Heat Transfer Measurements In An Advanced Gas Turbine Vane Insert Using Magnetic Resonance Velocimetry And Infrared Thermometry, Michael Benson, David Bindon Cdt'19, Mattias Cooper Cdt'19, F. Todd Davidson, Benjamin Duhaime Cdt'19, David Helmer, Robert Woodings Cdt'19, Bret P. Van Poppel, Christopher J. Elkins, John P. Clark

West Point Research Papers

This work reports the results of paired experiments for a complex internal cooling flow within a gas turbine vane using magnetic resonance velocimetry (MRV) and steady-state infrared (IR) thermometry. A scaled model of the leading edge insert for a gas turbine vane with multi-pass impingement was designed, built using stereolithography fabrication methods, and tested using MRV techniques to collect a three-dimensional, three-component velocity field data set for a fully turbulent test case. Stagnation and recirculation zones were identified and assessed in terms of impact on potential cooling performance. A paired experiment employed an IR camera to measure the temperature profile ...


An Investigation Of Porous Materials For The Capture Of Concentrated Solar Energy, Elizabeth Blokker 2022 The University of Western Ontario

An Investigation Of Porous Materials For The Capture Of Concentrated Solar Energy, Elizabeth Blokker

Electronic Thesis and Dissertation Repository

Fossil fuel usage is resulting in climate change. There is a need to switch to renewable energies, but existing technologies lack the efficiency for wide-scale adoption. Concentrating solar energy to a receiver using a parabolic reflector is an efficient method of converting sunlight into thermal energy at a high efficiency. Current receivers suffer efficiency challenges due to significant re-radiation losses as they reach a high temperature at the front surface. This project is focused on the creation of a computational model to simulate the radiation heat transfer in porous geometries, which can be used to optimize the geometric properties of ...


A Review On Heat Flux Measurement Techniques In The Nano And Microscale, Miguel Moreno 2022 University of Nebraska - Lincoln

A Review On Heat Flux Measurement Techniques In The Nano And Microscale, Miguel Moreno

Honors Theses, University of Nebraska-Lincoln

Heat Flux measurements represent an important step in obtaining an accurate heat transfer profile in many engineering problems. Sensors capable of measuring this quantity have been around for decades, however, the increasing focus in nano and microscale applications in the industry and academia demands more accurate and smaller devices. This paper reviews some of the methods used to develop heat flux meters targeted to nano and microscale, as well as some calibration processes for the same. A combination of Luminescence and non-luminescence methods for direct and indirect measurement of heat flux will be discussed. A glimpse of what the future ...


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