Heat Transfer, Combustion Commons^™

Novel Design And Fabrication Of A High-Speed Transient Heat Flux Sensor For Application To Rotating Detonation Engines, Zachary Todd Tallman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rotating detonation engine (RDE) combustion systems have been a topic of interest in the pressure gain combustion community for their benefits over traditional gas turbine engine combustors. However, cooling requirements for these engines are significantly higher and less predictable than those of non-detonating engines. To understand and quantify the high-speed heat transfer dynamics within an RDE, a novel high-frequency heat flux sensor is presented. This study aims to design a robust, single-sided sensor that can withstand the high temperature and harsh environment of an RDE for extended durations. Screen printing is used to deposit a layered, platinum-yttria-stabilized zirconia (YSZ) film …

Obliquely Impinging Jet Heat Transfer Fields: Effects Of Mach Number On Nozzle-To-Plate Distance, Thinnesh Ragupathy

Masters Theses

This study investigates the consistent features of heat flux patterns on surfaces impacted by jets at various Mach numbers, ranging from 0.1 to 1.0. It utilizes temperature-sensitive paint (TSP) analysis to examine how these patterns change. The research also explores the presence of self-similarity in both the fluctuation of heat flux and skin friction patterns, which are derived from temperature and heat flux data. A semi-empirical model is proposed to explain this self-similarity, suggesting that Mach number primarily affects heat flux patterns through the recovery temperature at the impact site.

Understanding the self-similarity of heat flux patterns across different Mach …

Development And Applications Of A Sensor For Measurement Of Different Modes Of Heat Transfer On Foods In A Residential Oven., Kervins Petit-Bois

Electronic Theses and Dissertations

Thermal characterization of an oven is an important part of designing an oven. Understanding how changes in cooking algorithm, oven construction, and oven materials affect cooking performance is critical in ensuring that an oven is properly designed. Often temperature data is used to characterize oven behavior, but this neglects the mode of heat transfer used to achieve these temperatures. Several studies have compared the different modes of heat transfer and cooking performance and have shown that cooking performance in radiation dominated modes are different than in convection dominated modes. The goal of this study is to develop a heat flux …

Phase Change Materials-Assisted Heat Flux Reduction: Experiment And Numerical Analysis, Hussein J. Akeiber, Seyed Ehsan Hosseini, Mazlan A. Wahid, Hasanen M. Hussen, Abdulrahman Th Mohammad

Faculty Publications - Mechanical Engineering

Phase change materials (PCM) in the construction industry became attractive because of several interesting attributes, such as thermo-physical parameters, open air atmospheric condition usage, cost and the duty structure requirement. Thermal performance optimization of PCMs in terms of proficient storage of a large amount of heat or cold in a finite volume remains a challenging task. Implementation of PCMs in buildings to achieve thermal comfort for a specific climatic condition in Iraq is our main focus. From this standpoint, the present paper reports the experimental and numerical results on the lowering of heat flux inside a residential building using PCM, …

Designing A Heat Sink For Lithium-Ion Battery Packs In Electric Vehicles, Evan Foreman, Dylan Irvine, Aaron Jackson, Christopher Brandon Remington, Sam Endrizzi

Williams Honors College, Honors Research Projects

This report addresses the concepts and implementation of fluid cooled heat sink designs for an electric or hybrid vehicle battery. To determine the battery’s temperature and heat flux profile, testing was performed by measuring these values at multiple locations on a lithium-ion pouch battery using heat flux sensors and thermocouples during the charge and discharge cycles of the battery. Once the data was collected and analyzed, trendlines were fit to the heat flux data then used to create equations for the heat flux profile during the discharging stage. Each equation represented a specific region on the battery geometry. Four heat …

Designing A Heat Sink For Lithium-Ion Battery Packs In Electric Vehicles, Dylan Irvine, Evan Foreman, Christopher B. Remington, Aaron Jackson, Sam Endrizzi

Williams Honors College, Honors Research Projects

This report addresses the concepts and implementation of fluid cooled heat sink designs for an electric or hybrid vehicle battery. To determine the battery’s temperature and heat flux profile, testing was performed by measuring these values at multiple locations on a lithium-ion pouch battery using heat flux sensors and thermocouples during the charge and discharge cycles of the battery. Once the data was collected and analyzed, trendlines were fit to the heat flux data then used to create equations for the heat flux profile during the discharging stage. Each equation represented a specific region on the battery geometry. Four heat …

Transient And Quasi-Steady Thermal Behaviour Of A Building Envelope Due To Retrofitted Cavity Wall And Ceiling Insulation, Aimee Byrne, Gerard Byrne, Anna Davies, Anthony Robinson

Articles

Accurate understanding of the thermal behaviour of building components is essential for predicting heat-ing or cooling needs and facilitates the implementation of more successful energy saving strategies and retrofits. This paper focuses on a specific measure commonly introduced through the residential energy efficiency retrofit programmes in Ireland–insulation. Traditionally, assessments of the performance of building envelopes have been based on assumed thermal resistances of the materials involved, labora-tory tests and computer modelling. The aim of the present work is to investigate the in situ thermal behaviour of a case study building and its components under transient and quasi-steady environmental conditions, comparing …

Development Of Spray Cooling For High Heat Flux Electronics, Jeremy Scott Junghans

Graduate Theses and Dissertations

The thermal demands of modern day electronic systems require innovative thermal solutions. Spray cooling has proven to be able to cool heat fluxes orders of magnitude higher than traditional cooling methodologies. This work includes a comparison of spray cooling to standard thermal management methodologies. Key system parameters and considerations are discussed. The properties of available packaging materials and their effect on the reliability of a spray cooled system are presented. Parameters such as fluid temperature, droplet size, fluid velocity and flow rate all directly impact performance and are detailed in this work. Finally, results from of a wide range of …

Singular Superposition/Boundary Element Method For Reconstruction Of Multi-Dimensional Heat Flux Distributions With Application To Film Cooling Holes, Mahmood Silieti, Eduardo Divo, Alain J. Kassab

Publications

A hybrid singularity superposition/boundary element-based inverse problem method for the reconstruction of multi-dimensional heat flux distributions is developed. Cauchy conditions are imposed at exposed surfaces that are readily reached for measurements while convective boundary conditions are unknown at surfaces that are not amenable to measurements such as the walls of the cooling holes. The purpose of the inverse analysis is to determine the heat flux distribution along cooling hole surfaces. This is accomplished in an iterative process by distributing a set of singularities (sinks) inside the physical boundaries of the cooling hole (usually along cooling hole centerline) with a given …