Opaque Gd2Zr2O7/GdMnO3 thermal barrier materials for thermal radiation shielding: the effect of polaron excitation

2021 ◽  
Author(s):  
Muzhang Huang ◽  
Jia Liang ◽  
Peng Zhang ◽  
Yi Li ◽  
Yi Han ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Radiation Shielding ◽  
Thermal Barrier ◽  
Barrier Materials

Effect of soot on thermal radiation shielding performance of water mist

2021 ◽  
Vol 123 ◽  
pp. 103363
Author(s):  
Hiroki Gonome ◽  
Yuto Takagi ◽  
Taichi Nagao ◽  
Mizuho Ono
Keyword(s):  
Thermal Radiation ◽  
Water Mist ◽  
Radiation Shielding

Thermal Radiation Shielding Applied to Polymeric Repair

2021 ◽  
Author(s):  
Robson Silva ◽  
Fabio Toshio Kanizawa
Keyword(s):  
Thermal Radiation ◽  
Radiation Shielding

High Temperature Radiation Heat Transfer Performance of Thermal Barrier Coatings With Multiple Layered Structures

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Xiao Huang
Keyword(s):  
Heat Transfer ◽  
Thermal Radiation ◽  
Thermal Barrier Coatings ◽  
Wavelength Range ◽  
Coating Thickness ◽  
Single Layer ◽  
Layered Structures ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Layered Coating

Meeting the demands for ever increasing operating temperatures in gas turbines requires concurrent development in cooling technologies, new generations of superalloys, and thermal barrier coatings (TBCs) with increased insulation capability. In the case of the latter, considerable research continues to focus on new coating material compositions, the alloying/doping of existing yttria stabilized zirconia ceramics, and the development of improved coating microstructures. The advent of the electron beam physical vapor deposition coating process has made it possible to consider the creation of multiple layered coating structures to meet specific performance requirements. In this paper, the advantages of layered structures are first reviewed in terms of their functions in impeding thermal conduction (via phonons) and thermal radiation (via photons). Subsequently, the design and performance of new multiple layered coating structures based on multiple layered stacks will be detailed. Designed with the primary objective to reduce thermal radiation transport through TBC systems, the multiple layered structures consist of several highly reflective multiple layered stacks, with each stack used to reflect a targeted radiation wavelength range. Two ceramic materials with alternating high and low refractive indices are used in the stacks to provide multiple-beam interference. A broadband reflection of the required wavelength range is obtained using a sufficient number of stacks. In order to achieve an 80% reflectance to thermal radiation in the wavelength range 0.3–5.3μm, 12 stacks, each containing 12 layers, are needed, resulting in a total thickness of 44.9μm. Using a one dimensional heat transfer model, the steady state heat transfer through the multiple layered TBC system is computed. Various coating configurations combining multiple layered stacks along with a single layer are evaluated in terms of the temperature profile in the TBC system. When compared with a base line single layered coating structure of the same thickness, it is estimated that the temperature on the metal surface can be reduced by as much as 90°C due to the use of multiple layered coating configurations. This reduction in metal surface temperature, however, diminishes with increasing the scattering coefficient of the coating and the total coating thickness. It is also apparent that using a multiple layered structure throughout the coating thickness may not offer the best thermal insulation; rather, placing multiple layered stacks on top of a single layer can provide a more efficient approach to reducing the heat transport of the TBC system.

Mechanical Properties of Thermal Barrier Materials Program

1973 ◽  
Author(s):  
K. E. Muszar ◽  
N. B. Edenborough
Keyword(s):  
Mechanical Properties ◽  
Thermal Barrier ◽  
Barrier Materials

scholarly journals Thermal barrier materials of Yb2O3-ZrO2 system synthesized by laser excitation

2020 ◽  
Vol 7 (5) ◽  
pp. 055201
Author(s):  
Jiayang He ◽  
Yanwei Huang ◽  
Mengyun Hu ◽  
Mengci Jiang ◽  
Yu Qiao ◽  
...  
Keyword(s):  
Laser Excitation ◽  
Thermal Barrier ◽  
Barrier Materials ◽  
Zro2 System

Hertzian and Nanoindentations on EBPVD-Coated Gadolinium Zirconate Thermal Barrier Materials

2007 ◽  
pp. 1349-1353
Author(s):  
Kyu Ick Jung ◽  
Sang Hyun Park ◽  
Jong Ho Kim ◽  
Do Kyung Kim ◽  
Un Gyu Paik ◽  
...  
Keyword(s):  
Thermal Barrier ◽  
Gadolinium Zirconate ◽  
Barrier Materials

High Temperature Radiation Heat Transfer Performance of Thermal Barrier Coatings With Multiple Layered Structures

2008 ◽  
Author(s):  
Xiao Huang
Keyword(s):  
Heat Transfer ◽  
Thermal Radiation ◽  
Thermal Barrier Coatings ◽  
Wavelength Range ◽  
Coating Thickness ◽  
Single Layer ◽  
Layered Structures ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Layered Coating

Meeting the demands for ever increasing operating temperatures in gas turbines requires concurrent development in cooling technologies, new generations of superalloys, and thermal barrier coatings (TBCs) with increased insulation capability. In the case of the latter, considerable research continues to focus on new coating material compositions, alloying/doping existing yttria stabilized zirconia ceramics, and the development of improved coating microstructures. The advent of the EB-PVD coating process has made it possible to consider the creation of multiple layered coating structures to meet specific performance requirements. In this paper, the advantages of layered structures are first reviewed in terms of their functions in impeding thermal conduction (via phonons) and thermal radiation (via photons). Subsequently, the design and performance of new multiple layered coating structures based on multiple layered stacks will be detailed. Designed with the primary objective to reduce thermal radiation transport through TBC systems, the multiple layered structures consist of several highly reflective multiple layered stacks, with each stack used to reflect a targeted radiation wavelength range. Two ceramic materials with alternating high and low refractive indices are used in the stacks to provide multiple-beam interference. A broadband reflection of the required wavelength range is obtained using a sufficient number of stacks. In order to achieve 80% reflectance to thermal radiation in the wavelength range of 0.3 ∼ 5.3 μm, 12 stacks, each containing 12 layers, are needed, resulting in a total thickness of 44.9 μm. Using a one dimensional heat transfer model, steady state heat transfer through the multiple layered TBC system is computed. Various coating configurations combining multiple layered stacks along with a single layer are evaluated in terms of the temperature profile in the TBC system. When compared to a baseline single layered coating structure of the same thickness, it is estimated that the temperature on the metal surface can be reduced by as much as 90°C due to the use of multiple layered coating configurations. This reduction in metal surface temperature, however, diminishes with increasing scattering coefficient of the coating and total coating thickness. It is also apparent that using a multiple layered structure throughout the coating thickness may not offer the best thermal insulation; rather, placing multiple layered stacks on top of a single layer can provide a more efficient approach to reduce the heat transport of the TBC system.

Impact of scattered radiation on thermal radiation shielding by water curtains

2021 ◽  
Vol 154 ◽  
pp. 278-290
Author(s):  
I.S. Voytkov ◽  
R.S. Volkov ◽  
N.P. Kopylov ◽  
E.Yu. Syshkina ◽  
A.V. Tomilin ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Scattered Radiation ◽  
Radiation Shielding
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