Keywords

PDC, SiCN, SiAlCN, Anemometer, heat flux sensor, gasturbine, high temperature, MEMS, Sensor, Ceramic

Abstract

Technical challenges for developing micro sensors for Ultra High Temperature and turbine applications lie in that the sensors have to survive extremely harsh working conditions that exist when converting fuel to energy. These conditions include high temperatures (500-1500°C), elevated pressures (200-400 psi), pressure oscillations, corrosive environments (oxidizing conditions, gaseous alkali, and water vapors), surface coating or fouling, and high particulate loading. Several technologies are currently underdeveloped for measuring these parameters in turbine engines. One of them is an optical-based non-contact technology. However, these nondirective measuring technologies lack the necessary accuracy, at least at present state. An alternative way to measure these parameters without disturbing the working environments is using MEMS type sensors. Currently, the techniques under development for such harsh environment applications are silicon carbide (SiC) and silicon nitrite (Si3N4) –based ceramic MEMS sensors. But those technologies present some limitation such as narrow processing method, high cost (materials and processing cost), and limited using temperatures (typically < 800 C). In this research we propose to develop two sensors based on recently developed polymer-derived ceramics (PDCs): Constant Temperature Hot wire Anemometer, temperature/heat-flux sensor for turbine applications. PDC is a new class of high temperature ceramics. As we shall describe below, many unique features of PDCs make them particularly suitable for the proposed sensors, including: excellent thermo-mechanical properties at high temperatures, enable high temperature operation of the devices; various well-developed processing technologies, such as injection molding,photolithography, embossing, DRIE etching and precise machining, can be used for the fabrication of the devices; and tunable electric conductivity, enable the proposed sensors fabricated from similar materials, thus reliability considerations associated with thermal mismatch, which is a big concern when using MEMS-based sensors at elevated temperatures, will be minimized.

Notes

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Graduation Date

2006

Semester

Summer

Advisor

Kapat, Jayanta;

Degree

Master of Science in Mechanical Engineering (M.S.M.E.)

College

College of Engineering and Computer Science

Department

Mechanical, Materials and Aerospace Engineering;

Degree Program

Mechanical Engineering

Format

application/pdf

Identifier

CFE0001285

URL

http://purl.fcla.edu/fcla/etd/CFE0001285

Language

English

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

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