A Systematic Study on the Mechanical and Thermal Properties of Open Cell Metal Foams for Aerospace Applications

dc.contributor.advisorDr. Jeffrey Eischen, Committee Memberen_US
dc.contributor.advisorDr. William Robertrs, Committee Memberen_US
dc.contributor.advisorDr. Afsaneh Rabiei, Committee Chairen_US
dc.contributor.authorAzzi, Wassim Eliasen_US
dc.date.accessioned2010-04-02T18:18:48Z
dc.date.available2010-04-02T18:18:48Z
dc.date.issued2004-12-01en_US
dc.degree.disciplineMechanical Engineeringen_US
dc.degree.levelthesisen_US
dc.degree.nameMen_US
dc.description.abstractJet engine operating temperatures have been on the rise since the inception of the jet engine. High Operating temperatures mean increased efficiency, more power, and lesser emissions. However, operating temperatures of jet engines are limited by the operating temperatures of the turbine material. This temperature must not be exceeded or else it will damage the turbine components. To solve this problem, complex cooling schemes have been adopted. They employ the use of outside air to dilute the high combustion temperatures to make them suitable for turbine section exposure. This leads to a non-uniform temperature profile leaving the combustion area and therefore decreasing the overall engine performance by introducing thermal cycling and inconsistencies in operational temperatures. This research suggests placing an ultra-high temperature open cell metal foam ring in front of the combustion area and directly before the turbine section. Open cell foam with their 3-dimensional geometry help mix the hot and cool gasses entering the turbine area creating a more uniform temperature profile. This increases efficiency by raising the operational temperature of the jet engine. It also contributes to an increased lifetime since the mixing function of the metallic foam will reduce thermal cycling fatigue on turbine vanes and blades. This research presents a full investigation on the feasibility of this idea; it studies the potential of producing ultra-high temperature metallic foam from a list of currently available as well recently engineered materials. This work also investigates the pressure drop and heat transfer associated with the foam for a full assessment of the design. Infrared imaging for heat transfer measurements done on Al foam of 5 and 10 PPI (pores per inch) samples showed the mixing role of the metal foam as a function of thickness; it showed improvement of the temperature profile resulting from the averaging the hot and the cool gasses. Pressure drop testing provided data on pressure drop in Al foams in the compressibility region of air. Up to this point, similar data was not available. Pressure drop testing revealed that with careful design of pore size, ligament thickness and foam thickness, taking into consideration heat transfer capabilities of the foam, a feasible design of an ultra-high temperature open cell foam ring can be achieved with minimal pressure drop and increased heat transfer capabilities.en_US
dc.identifier.otheretd-11282004-014635en_US
dc.identifier.urihttp://www.lib.ncsu.edu/resolver/1840.16/2922
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectfoamen_US
dc.subjectjet engineen_US
dc.subjectporousen_US
dc.subjectheat transferen_US
dc.subjectopen cellen_US
dc.titleA Systematic Study on the Mechanical and Thermal Properties of Open Cell Metal Foams for Aerospace Applicationsen_US

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