Development of High-Temperature Position Sensors for Control of Actuators in Aerospace Systems

Author(s):  
Yongdae Kim ◽  
Hyun Young Choi
2020 ◽  
Vol 321 ◽  
pp. 04013
Author(s):  
Sesh Tamirisakandala ◽  
Ernie Crist ◽  
Fusheng Sun ◽  
Matthew Dahar

Next generation fuel-efficient jet engines are running hotter presenting a structural challenge for the exhaust systems and structures adjacent to the engines. A conventional and affordable titanium alloy with superior oxidation resistance provides significant weight reductions and associated cost savings by eliminating the need for high density material systems such as nickel-base superalloys for service temperatures in between current titanium and nickel, enabling major technology advancement in high temperature aerospace applications. This paper presents an overview of Arconic’s engineered material ARCONIC-THORTM to address the needs of future aerospace systems.


Author(s):  
Rodrigo Villalva ◽  
Brian Dolan ◽  
David Munday ◽  
Ephriam Gutmark ◽  
Gregory Zink ◽  
...  

Emissions measurements were performed on a low-NOx emission combustor concept developed by United Technologies Aerospace Systems (formerly Goodrich) for NASA’s Environmentally Responsible Aircraft (ERA) program to meet N+2 emissions goals for a 70,000 pound thrust engine application. A key enabler of this goal is to improve combustion stability at low power conditions over that of previous work. The combustion system presented potentially substitutes five radially staged small injectors for a single row of larger injectors. The test combustor has a total of 13 individual fuel injectors distributed in five rows. NOx, CO, and UHC were measured for a variety of practical conditions, from lean blow-out to idle and simulated full power. Imaging provided insight on how the staged injectors perform and contribute to observed emissions. Conditions which yield significant NOx reductions were identified and correlate well to existing literature. In particular, evenly distributed combustion among all 13 fuel injectors reduced regions of high temperature and resulted in significant NOx reductions which correlate well with demonstrated performance of other multi-point combustors.


2016 ◽  
Vol 16 (19) ◽  
pp. 7065-7072 ◽  
Author(s):  
Yongdae Kim ◽  
Hyun Young Choi

Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.


Author(s):  
B. J. Hockey

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.


Author(s):  
D. R. Clarke ◽  
G. Thomas

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.


Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.


Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization


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