Experimental Performance Of A Micromachined Heat Flux Sensor

Author : S. Stefanescu
Publisher : Unknown
Page : 18 pages
File Size : 45,8 Mb
Release : 1998
Category : Electronic
ISBN : NASA:31769000615602

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Experimental Performance of a Micromachined Heat Flux Sensor by S. Stefanescu Pdf

Steady-state and frequency response calibration of a microfabricated heat-flux sensor have been completed. This sensor is batch fabricated using standard, micromachining techniques, allowing both miniaturization and the ability to create arrays of sensors and their corresponding interconnects. Both high-frequency and spatial response is desired, so the sensors are both thin and of small cross-sectional area. Thin-film, temperature-sensitive resistors are used as the active gauge elements. Two sensor configurations are investigated: (1) a Wheatstone-bridge using four resistors; and (2) a simple, two-resistor design. In each design, one resistor (or pair) is covered by a thin layer (5000 A) thermal barrier; the other resistor (or pair) is covered by a thick (5 microns) thermal barrier. The active area of a single resistor is 360 microns by 360 microns; the total gauge area is 1.5 mm square. The resistors are made of 2000 A-thick metal; and the entire gauge is fabricated on a 25 microns-thick flexible, polyimide substrate. Heat flux through the surface changes the temperature of the resistors and produces a corresponding change in resistance. Sensors were calibrated using two radiation heat sources: (1) a furnace for steady-state, and (2) a light and chopper for frequency response.

Author : Anonim
Publisher : Unknown
Page : 768 pages
File Size : 49,6 Mb
Release : 2000
Category : Government publications
ISBN : OSU:32437121144709

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Monthly Catalog of United States Government Publications by Anonim Pdf

Author : J. M. Hager (Of Vatell Corp.)
Publisher : Unknown
Page : 0 pages
File Size : 54,7 Mb
Release : 1990
Category : Boundary layer
ISBN : OCLC:1427206194

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Experimental Performance of a Heat Flux Microsensor by J. M. Hager (Of Vatell Corp.) Pdf

The performance characteristics of a heat flux microsensor have been measured and analyzed. This is a new heat flux gage system that is made using microfabrication techniques. The gages are small, have high frequency response, can measure very high heat flux, and output a voltage directly proportional to the heat flux. Each gage consists of a thin thermal resistance layer sandwiched between many thermocouple pairs forming a differential thermopile. Because the gage is made directly on the measurement surface and the total thickness is less than 2 micrometer, the presence of the gage contributes negligible flow and thermal disruption. The active surface area of the gage is 3 mm by 4 mm, with the leads attached outside this area to relay the surface heat flux and temperature signals. Gages were made and tested on glass and silicon substrates. The steady and unsteady response was measured experimentally and compared with analytical predictions. The analysis was performed using a one-dimensional, transient, finite-difference model of the six layers comprising the gage plus the substrate. Steady-state calibrations were done on a convection heat transfer apparatus and the transient response was measured to step changes of the imposed radiative flux. As an example of the potential capabilities, the time-resolved heat flux was measured at a stagnation point with imposed free-stream turbulence. A hot-film probe placed outside the boundary layer was used to provide a simultaneous signal showing the corresponding turbulent velocity fluctuations.

Author : Daniel Ng
Publisher : Unknown
Page : 14 pages
File Size : 40,6 Mb
Release : 1993
Category : Electronic
ISBN : NASA:31769000604408

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Non-contact Heat Flux Measurement Using a Transparent Sensor by Daniel Ng Pdf

Author : Anonim
Publisher : Unknown
Page : 652 pages
File Size : 40,5 Mb
Release : 1997
Category : Aeronautics
ISBN : STANFORD:36105020229832

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Aerospace America by Anonim Pdf

Author : Sergey Z. Sapozhnikov,Vladimir Yu. Mityakov,Andrey V. Mityakov
Publisher : Springer Nature
Page : 225 pages
File Size : 40,5 Mb
Release : 2020-03-03
Category : Science
ISBN : 9783030408541

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Heatmetry by Sergey Z. Sapozhnikov,Vladimir Yu. Mityakov,Andrey V. Mityakov Pdf

This book is a translation from a Russian book. In 2007, the authors created a new generation of layered composite-based sensors, whose advantages are high technology and thermal stability. The use of gradient heat flux sensors in laboratory and industrial conditions confirmed their reliability, showed high information, and allowed a number of priority results to be obtained. All of this is summarized in this book.

Author : Anonim
Publisher : Unknown
Page : 1044 pages
File Size : 54,5 Mb
Release : 1999
Category : Aeronautics
ISBN : STANFORD:36105021812214

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International Aerospace Abstracts by Anonim Pdf

Author : Stéphane Colin
Publisher : John Wiley & Sons
Page : 313 pages
File Size : 43,7 Mb
Release : 2013-05-06
Category : Technology & Engineering
ISBN : 9781118599884

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Microfluidics by Stéphane Colin Pdf

The recent development of microscale technologies makes it possible to design complex microsystems devoted to transport, dosing, mixing, analysis or even synthesis of fluids. Applications are numerous and exist in almost every industrial field, from biotechnology and healthcare to aeronautics and advanced materials manufacturing. Microfluidics is a relatively new research area, usually comprising work with microsystems and involving internal fluid flows with characteristic dimensions of the order of one micrometer (1 x 10 -6 m). This book provides engineers and researchers with a range of tools for modeling, experimenting on, and simulating these microflows, as a preliminary step in designing and optimizing fluidic microsystems. The various consequences of miniaturization on the hydrodynamics of gas, liquid or two-phase flows, as well as on associated heat transfer phenonema, are analyzed. The book is illustrated with examples that demonstrate the wide diversity of applications, and the breadth of novel uses of these fluidic microsystems.

Author : Mahmoud Rasras,Ibrahim (Abe) M. Elfadel,Ha Duong Ngo
Publisher : MDPI
Page : 252 pages
File Size : 55,9 Mb
Release : 2019-05-27
Category : Technology & Engineering
ISBN : 9783038974147

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MEMS Accelerometers by Mahmoud Rasras,Ibrahim (Abe) M. Elfadel,Ha Duong Ngo Pdf

Micro-electro-mechanical system (MEMS) devices are widely used for inertia, pressure, and ultrasound sensing applications. Research on integrated MEMS technology has undergone extensive development driven by the requirements of a compact footprint, low cost, and increased functionality. Accelerometers are among the most widely used sensors implemented in MEMS technology. MEMS accelerometers are showing a growing presence in almost all industries ranging from automotive to medical. A traditional MEMS accelerometer employs a proof mass suspended to springs, which displaces in response to an external acceleration. A single proof mass can be used for one- or multi-axis sensing. A variety of transduction mechanisms have been used to detect the displacement. They include capacitive, piezoelectric, thermal, tunneling, and optical mechanisms. Capacitive accelerometers are widely used due to their DC measurement interface, thermal stability, reliability, and low cost. However, they are sensitive to electromagnetic field interferences and have poor performance for high-end applications (e.g., precise attitude control for the satellite). Over the past three decades, steady progress has been made in the area of optical accelerometers for high-performance and high-sensitivity applications but several challenges are still to be tackled by researchers and engineers to fully realize opto-mechanical accelerometers, such as chip-scale integration, scaling, low bandwidth, etc. This Special Issue on "MEMS Accelerometers" seeks to highlight research papers, short communications, and review articles that focus on: Novel designs, fabrication platforms, characterization, optimization, and modeling of MEMS accelerometers. Alternative transduction techniques with special emphasis on opto-mechanical sensing. Novel applications employing MEMS accelerometers for consumer electronics, industries, medicine, entertainment, navigation, etc. Multi-physics design tools and methodologies, including MEMS-electronics co-design. Novel accelerometer technologies and 9DoF IMU integration. Multi-accelerometer platforms and their data fusion.

Author : Je-Chin Han,Lesley M. Wright
Publisher : CRC Press
Page : 338 pages
File Size : 44,7 Mb
Release : 2020-05-20
Category : Science
ISBN : 9781000072167

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Experimental Methods in Heat Transfer and Fluid Mechanics by Je-Chin Han,Lesley M. Wright Pdf

Experimental Methods in Heat Transfer and Fluid Mechanics focuses on how to analyze and solve the classic heat transfer and fluid mechanics measurement problems in one book. This work serves the need of graduate students and researchers looking for advanced measurement techniques for thermal, flow, and heat transfer engineering applications. The text focuses on analyzing and solving classic heat transfer and fluid mechanics measurement problems, emphasizing fundamental principles, measurement techniques, data presentation, and uncertainty analysis. Overall, the text builds a strong and practical background for solving complex engineering heat transfer and fluid flow problems. Features Provides students with an understandable introduction to thermal-fluid measurement Covers heat transfer and fluid mechanics measurements from basic to advanced methods Explains and compares various thermal-fluid experimental and measurement techniques Uses a step-by-step approach to explaining key measurement principles Gives measurement procedures that readers can easily follow and apply in the lab

Author : C.B. Sobhan,G.P. Peterson
Publisher : CRC Press
Page : 317 pages
File Size : 53,7 Mb
Release : 2008-06-12
Category : Science
ISBN : 9781000654219

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Microscale and Nanoscale Heat Transfer by C.B. Sobhan,G.P. Peterson Pdf

Through analyses, experimental results, and worked-out numerical examples, Microscale and Nanoscale Heat Transfer: Fundamentals and Engineering Applications explores the methods and observations of thermophysical phenomena in size-affected domains. Compiling the most relevant findings from the literature, along with results from their own re

Author : S. M. Sohel Murshed
Publisher : BoD – Books on Demand
Page : 184 pages
File Size : 40,5 Mb
Release : 2016-06-15
Category : Computers
ISBN : 9789535124054

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Electronics Cooling by S. M. Sohel Murshed Pdf

Featuring contributions from the renowned researchers and academicians in the field, this book covers key conventional and emerging cooling techniques and coolants for electronics cooling. It includes following thematic topics: - Cooling approaches and coolants - Boiling and phase change-based technologies - Heat pipes-based cooling - Microchannels cooling systems - Heat loop cooling technology - Nanofluids as coolants - Theoretical development for the junction temperature of package chips. This book is intended to be a reference source and guide to researchers, engineers, postgraduate students, and academicians in the fields of thermal management and cooling technologies as well as for people in the electronics and semiconductors industries.

Author : Anonim
Publisher : Academic Press
Page : 524 pages
File Size : 42,6 Mb
Release : 1999-02-24
Category : Science
ISBN : 0080575870

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Advances in Heat Transfer by Anonim Pdf

Advances in Heat Transfer is designed to fill the information gap between regularly scheduled journals and university level textbooks by providing in-depth review articles over a broader scope than is allowable in either journals or texts.

Author : Anonim
Publisher : Newnes
Page : 3572 pages
File Size : 43,9 Mb
Release : 2011-01-28
Category : Science
ISBN : 9780080932286

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Comprehensive Semiconductor Science and Technology by Anonim Pdf

Semiconductors are at the heart of modern living. Almost everything we do, be it work, travel, communication, or entertainment, all depend on some feature of semiconductor technology. Comprehensive Semiconductor Science and Technology, Six Volume Set captures the breadth of this important field, and presents it in a single source to the large audience who study, make, and exploit semiconductors. Previous attempts at this achievement have been abbreviated, and have omitted important topics. Written and Edited by a truly international team of experts, this work delivers an objective yet cohesive global review of the semiconductor world. The work is divided into three sections. The first section is concerned with the fundamental physics of semiconductors, showing how the electronic features and the lattice dynamics change drastically when systems vary from bulk to a low-dimensional structure and further to a nanometer size. Throughout this section there is an emphasis on the full understanding of the underlying physics. The second section deals largely with the transformation of the conceptual framework of solid state physics into devices and systems which require the growth of extremely high purity, nearly defect-free bulk and epitaxial materials. The last section is devoted to exploitation of the knowledge described in the previous sections to highlight the spectrum of devices we see all around us. Provides a comprehensive global picture of the semiconductor world Each of the work's three sections presents a complete description of one aspect of the whole Written and Edited by a truly international team of experts

Author : Julia Hoeng,David Bovard,Manuel Peitsch
Publisher : Academic Press
Page : 546 pages
File Size : 49,9 Mb
Release : 2019-11-09
Category : Technology & Engineering
ISBN : 9780128172032

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Organ-on-a-chip by Julia Hoeng,David Bovard,Manuel Peitsch Pdf

Organ-on-a-Chip: Engineered Microenvironments for Safety and Efficacy Testing contains chapters from world-leading researchers in the field of organ on a chip development and applications, with perspectives from life sciences, medicine, physiology and engineering. The book contains an overview of the field, with sections covering the major organ systems and currently available technologies, platforms and methods. As readers may also be interested in creating biochips, materials and engineering best practice, these topics are also described. Users will learn about the limitations of 2D in-vitro models and the available 3D in-vitro models (what benefits they offer and some examples). Finally, the MOC section shows how the organ on a chip technology can be adapted to improve the physiology of in-vitro models. Includes case studies of other organs on a chip that have been developed and successfully used Provides insights into functional microphysiological organ on a chip platforms for toxicity and efficacy testing, along with opportunities for translational medicine Presented fields (PK/PD, physiology, medicine, safety) are given a definition followed by the challenges and potential of organs on a chip