Heat Transfer, Combustion Commons^™

Performance Augmentation Of Single-Slope Solar Distiller Using An Evacuated Tube Solar Collector: Theoretical Study, Eman Mohammed Abuelezz Eng., Yasser El-Samadony Prof., Khaled Khodary Esmaeil Assoc. Prof., Mohamed Elsheshtawy Zayed Dr.

Journal of Engineering Research

In this research, the performance analysis of a solar-powered desalination system incorporating a single slope-slope solar still and an evacuated tube solar collector is theoretically investigated. The system comprises a solar evacuated tube that absorbs solar radiation, transferring heat to saline water. This water then flows into a solar still, where it absorbs solar energy, boosting the evaporation rate. Two solar distillers, namely the conventional solar distiller (Still-I) and solar still integrated with evacuated tube solar collector (Still-II), are simulated and analyzed under identical outdoor conditions in Tanta, Egypt. A comprehensive theoretical model, developed using FORTAN programming, simulates the performance …

Modeling Thermosyphon And Heat Pipe Performance For Mold Cooling Applications, Dwaipayan Sarkar

Electronic Thesis and Dissertation Repository

Thermosyphons are enhanced heat transfer devices that can continuously transfer very large amounts of heat rapidly over long distances with small temperature differences. The high heat transfer rate is achieved through simultaneous boiling and condensation of the working fluid and the continuous heat transfer is achieved through recirculation of the working fluid in its liquid and vapor phase. A potentially important application of the thermosyphons has been towards reducing the cycle times of the mold cooling processes which would provide economic incentives to the automotive industry.

Different operational and geometrical parameters such as the input heating power, fill ratio (FR), …

Liquid Nitrogen Shrink-Fitting Process, Natalie Harvey

The Journal of Purdue Undergraduate Research

No abstract provided.

Enhancing The Performance Of Conventional Solar Still Using The Nano-Doped Paint (Ndp) Coating, Hagar Alm-Eldin Bastawissi Prof.Dr, Nermin Elgendy Engineer, Ayman R. El-Tohamy

Journal of Engineering Research

Nations are throughout the entire globe continuously confronting the problem of potable water shortage. Recently, it has been thought that using solar energy to desalinate brackish water offers a practical answer to the world's water crises. The output of these stills, is meager, and academics haven't done much to boost it in any way. Solar distillers have been proposed as an efficient method to produce potable water. In recent years, saltwater has produced drinking water by various ways. The efficiency of a solar distiller is significantly influenced by various factors, most important factor of them is the absorber surface. In …

Depressurization Characteristics Of Steam-Based Reciprocating Vacuum Pump, Hongling Deng

Dissertations

This dissertation introduces a novel vacuum technology that leverages low-pressure saturated steam and cooling-controlled condensation, offering an efficient way to utilize low-grade thermal energy sources like waste heat, steam, or solar energy. At the heart of this technology is a unique duo-chamber vacuum pump system, featuring a reciprocating piston and a heat-conductive wall, designed to generate a vacuum through steam-condensation and cooling processes.

The core of this research lies in developing and validating mechanistic models for the steam-condensation depressurization process, a complex phenomenon involving phase change and transport mechanisms. Prior to this work, these mechanisms were not sufficiently modeled or …

Heat Transfer Enhancement In Nanofluid Flows Augmented By Magnetic Flux, Kozhikkatil Sunil Arjun, Rakesh Kumar

Makara Journal of Technology

Heat transfer enhancement could be realized using magnetohydrodynamics together with nanofluids specifically in flow micro-convection in a microtube, flow past a vertical porous plate, and square duct flow with discrete heat sources numerically. A critical value for the Rayleigh number, a maximum value for the magnetic field strength, a low Reynolds number, and volume concentrations exists for thermal enhancement to simulate nanofluid flow in a microtube. Heat transfer enhancement is observed with a reduction in the magnetic field strength in a flow past a heated porous vertical plate. Alumina nanofluid subjected to Hartmann number 10 can boost 81% enhancement in …

Effects Of Back Reflectors And Thin Metal Covers On The Performance Of Near-Field Thermophotovoltaic Devices, Mehran Habibzadeh

Electronic Theses and Dissertations

Highly efficient energy harvesting devices that can recover a large amount of waste energy are of significant interest. Thermophotovoltaics (TPVs) are solid-state devices that can convert thermal energy radiated by a heated emitter into electrical power through the process of photovoltaic effect. In a TPV system, heat is converted to electricity by using a high-temperature emitter to radiate photons, which are then absorbed by a photovoltaic (PV) cell, generating electron-hole pairs and producing electrical power.

TPV devices have the advantages of producing High efficiency and being lightweight with low maintenance cost and zero pollution. However, these devices have not been …

Experimental Measurement Of Near-Field Radiative Heat Transfer Between Two Macroscale Planar Media, Md Shofiqul Islam

Electronic Theses and Dissertations

Radiative heat transfer between two media separated by a gap smaller than the wavelength of thermal radiation (10 μm at room temperature) is referred to as near-field RHT. Near-field RHT exceeds the RHT between two blackbodies which is the maximum limit for RHT in the far-field regime (i.e., when the separation gap is much larger than the thermal wavelength). Due to this enhanced heat transfer, near-field RHT has found promising applications, for power enhancement of thermophotovoltaic devices, thermal rectification, localized cooling, and photonic cooling to name only a few. Graphene is an ideal material for near-field RHT applications as it …

Study Of Multi-Dimensional Transfer Effects In Applied Smouldering Systems, Seyed Ziaedin Miry Mr

Electronic Thesis and Dissertation Repository

Smouldering is a flameless form of combustion that is driven by oxygen directly diffusing into the surface of condensed phase fuel (liquid or solid) and involves a complex interplay between heat and mass transfer through porous media, chemical reactions, and multiphase flow. Applied smouldering systems have been gaining popularity for a variety of applications including (i) energy and resource recovery, (ii) waste-to-energy, (iii) pyrolysis and gasification, and (iv) applied smouldering of organic liquids/solids for environmental benefits. In all contexts, smouldering is a complicated oxygen-limited phenomenon where multi-dimensional transfer effects (i.e., non-uniformities in …

An Image Processing Technique For Studying The Flame Structure Using Single Shots Of Oh-Plif Diagnostics, Hazem M. Al-Bulqini, El-Shafie B. Zeidan, Farouk M. Okasha, Mohy S. Mansour

Mansoura Engineering Journal

Laser diagnostic techniques have played a crucial role in enhancing our understanding of combustion processes. Among these techniques, Planar Laser-Induced Fluorescence (PLIF) utilizing OH radicals has proven to be a powerful tool for investigating reaction zones, flame curvature, and flame surface density in diverse flame modes including premixed, non-premixed, and partially premixed flames. However, to fully harness the potential of experimental measurements and laser diagnostics in studying combustion processes, a comprehensive grasp of image processing techniques and tools is essential for effectively analyzing captured images and extracting valuable information. In this study, we present a detailed algorithm that facilitates the …

Additively Manufactured Nature Inspired Morphology For Redesign: Advancing Next Generation Energy Systems, Vanshika Singh

Doctoral Dissertations

To meet cleaner energy goals and increasing demand, energy systems such as gas turbines and power plants are required to be operated under harsh loading conditions like higher temperatures and pressures, fluctuating loads, and corrosive environments. Advanced manufacturing techniques such as additive manufacturing (AM) have put us on the trajectory for next-generation system designs, allowing complex geometries and high-temperature alloys with tailored material properties. We need new and systematic design philosophies to use AM's unique characteristics prudently. For a given functionality, nature tends to provide similar solutions in animate and inanimate structures. We propose to take inspiration from nature's repetitive …

Capabilities Of Sintered Silver As A High Temperature Packaging Material, Bakhtiyar Mohammad Nafis

Graduate Theses and Dissertations

With electrification progressing across many sectors including industry, automotive and aerospace, the power density requirements are changing. The increased power density results in higher and higher ambient temperatures that electronics are exposed to. The response has been to move towards wide bandgap (WBG) semiconductor devices that can withstand much greater temperatures and can operate at much higher voltages than silicon. Additionally, these WBG devices deliver low drain-source on resistance (RDS_on) capabilities, enabling high current power modules that increase power density even further. This also requires the packaging to evolve in order to withstand the new requirements. As a result, researchers …

Gpu Based Monte Carlo Estimation Of Eddy Current Losses In Electromagnetic Coil-Core System, Adwaith Ravichandran

Theses and Dissertations

A novel parallelizable probabilistic approach to model eddy currents in AC electromagnets is presented in this research. Consequently, power loss associated with the formation of these eddy currents is estimated and validated using experimental data. Furthermore, predicting the effect of ferromagnetic alternating field enhancement on power loss in the source excitation winding has been an active area of research. Unlike a stationary field, an alternating sinusoidal field diffuses partially into the ferromagnetic material leading to a predictably sub-optimal field enhancement. To model these physics, finite element techniques employ nonlinear iterative solvers which are time consuming. A novel method is developed …

Experimental Study On The Impact Of Low Thermal Inertia Thermal Barrier Coatings On Ppci-Diffusion Gci Combustion, Kunal Vedpathak

All Theses

The application of thermal barrier coatings (TBCs) has been studied in homogenous charge compression ignition (HCCI), conventional diesel combustion (CDC), and spark ignition (SI). Gasoline compression ignition (GCI) combines the low soot and NOx emissions of HCCI with combustion controllability through fuel stratification. GCI has become an interesting prospect due to the reduction in gasoline consumption due to the electrification and hybridization of the light-duty sector. It can be used as a preferred combustion mode in heavy-duty engines to reduce emissions with minimal modifications. GCI exhibits better combustion efficiency than HCCI. Advances in material technology have combined low thermal conductivity …

Thermal Resistance Characterization Of High-Voltage Sic Power Module, Landon Lemmons

Mechanical Engineering Undergraduate Honors Theses

Researchers within the University of Arkansas Electrical Engineering Research Department have embarked on a project aimed at enhancing the thermal performance of high-voltage power modules. To aid in the progress of this project, the design, and development of a thermal tester device are needed. The primary objective of this device is to determine the various thermal properties of high-voltage power modules that the electrical engineering department has developed. Additionally, the project aims to facilitate electrical loading tests on power modules and provide researchers with the means to calibrate the power module in terms of thermal load. This project also possesses …

An Investigation Into Computational Modelling Of Melting And Solidification Of Phase Change Materials, Maryam Hemmat

Electronic Thesis and Dissertation Repository

This thesis evaluates the effectiveness of the enthalpy-porosity approach in simulating melting and solidification of phase change materials within latent heat thermal energy storage systems. It systematically investigates the sensitivity of the computational model to four adjustable parameters: mushy zone coefficient, thermal expansion coefficient, solidus/liquidus temperatures, and latent heat. The study includes individual and combined analyses of these factors in simulations of the melting process by comparing outcomes with extensive experimental data, resulting in a calibrated melting model. The calibrated model is validated across various heating conditions in the cylindrical cavity, and then in a rectangular cavity, confirming its reliability …

Steady And Transient Study Of Conjugate Heat Transfer In Regenerative Cooled Nozzle, Khaled Bensayah, Khadidja Kamri

Emirates Journal for Engineering Research

The Heat transfer is one of the most serious challenges that exist in a supersonic nozzle flow. The combustion chamber wall and the nozzle are exposed to high-temperature gases during combustion and gas expansion, which can eventually lead to structural failure. This paper reports a computational study of steady and transient conjugate heat transfer in regenerative water cooled nozzle. Numerical computation solved Reynolds-averaged equations based on RSM-Omega turbulence model coupling with solid-phase heat conduction equation and with coolant-phase. The effect of four inlet cooled approach length 0 inch, 6 inch, 12 inch and 18 inch are studied and validated against …

Design And Characterization Of A High Pressure Flow Loop For Heat Transfer Experiments Of Supercritical Carbon Dioxide, Joseph Sauerbrun

Doctoral Dissertations and Master's Theses

Supercritical carbon dioxide (sCO2) sees heightened heat transfer characteristics near its critical point due to its drastically changing thermophysical properties. Conventional single phase heat transfer theory was not developed to capture this nonlinear variation in properties and cannot predict the heat transfer characteristics of sCO2 to a practical level useful for design. To delve deeper into the behavior near the critical point and shed light on this crucial phenomenon, a state-of-the-art closed flow loop was developed. This setup enabled convective heat transfer experiments of sCO2 under diverse boundary conditions and test section geometries. Key components of the loop include the …

Studying The Influential Parameters Of An Office Building’S Energy Consumption In North America, Naveen Raghava Krishnan Bhoopal

Major Papers

The study of building energy consumption has gained immense significance in recent times due to the burgeoning global population and the rapid depletion of energy resources. The present research focuses on analyzing individual parameters that impact building energy usage and devising methods and strategies to reduce energy consumption. An existing office building in Philadelphia was chosen as a reference for simulation in TRNSYS. The factors that affect the building, such as ambient temperature, solar radiation, building envelope, wind speed, and internal gains, were studied and defined according to the existing building standards. Predictive modeling is performed with these inputs for …

Accomplishments Of Endwall Contouring On Heat Transfer In A Passage Of A Turbine Blade, Kozhikkatil Sunil Arjun, Tide Porathoor Sunny, Narayanan Biju

Makara Journal of Technology

The study explores axisymmetric endwall contouring with emphasis on the design of novel endwalls capable of heat load reduction. Optimizations with parameterization numerically determined by the endwall of flat shape led to the endwall of the contoured shape with substantial depletion of heat transfer in the passage of the vane. Heat transfer attributes for the generated contoured endwalls were analyzed for the exit Reynolds number of 2 × 106 . Endwall three-dimensional contouring resulted in remarkable changes in secondary flow vortices, jet-to-secondary flow interaction, and film cooling effectiveness on the flat endwall. The results pointed out that the axisymmetric convergent …