Total Hemispherical Emissivity

2021 ◽  
pp. 27-33
Author(s):  
M. Kemal Atesmen
Keyword(s):  
Total Hemispherical Emissivity

scholarly journals Emissivity measurements on reflective insulation materials

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Albert Adibekyan ◽  
Elena Kononogova ◽  
Jacques Hameury ◽  
Marcus Lauenstein ◽  
Christian Monte ◽  
...  
Keyword(s):  
Power Generation ◽  
Absolute Measurement ◽  
Radiative Properties ◽  
Major Objective ◽  
Insulation Materials ◽  
Industrial Sectors ◽  
Accurate Knowledge ◽  
Satellite Applications ◽  
Total Hemispherical Emissivity ◽  
Emissivity Measurements

Abstract The development and use of new thermal insulation products in many industrial sectors, ranging from building insulations to power generation or satellite applications, requires the accurate knowledge of the radiative properties of the investigated material, i. e. its emissivity. A major objective of the research project “Improvement of emissivity measurements on reflective insulation materials” within the framework of the European Metrology Programme for Innovation and Research was to improve and validate reference techniques for the measurement of the total hemispherical emissivity of low emissivity foils with an absolute measurement uncertainty below 0.03. The calibration and measurement procedures developed within this project shall lead to a significant benefit for industrial manufacturers of reflective foils as well as for the end-users of the industrial instruments used to characterize them.

Effect of rare-earth dopant (Sm) concentration on total hemispherical emissivity and ablation resistance of ZrB2/SiC coatings

2016 ◽  
Vol 36 (16) ◽  
pp. 3833-3841 ◽  
Author(s):  
Winnie Tan ◽  
Mitchell Adducci ◽  
Christopher Petorak ◽  
Brian Thompson ◽  
Anneliese E. Brenner ◽  
...  
Keyword(s):  
Rare Earth ◽  
Ablation Resistance ◽  
Rare Earth Dopant ◽  
Sic Coatings ◽  
Total Hemispherical Emissivity

Research on the validity of the steady-state calorimeter for measuring the total hemispherical emissivity of solids

1993 ◽  
Vol 4 (7) ◽  
pp. 721-725 ◽  
Author(s):  
Cheng Shu Xia ◽  
Ge Xin Shi ◽  
Yao Cheng Cai ◽  
Gao Ju Wen ◽  
Zhang Yong Zhong
Keyword(s):  
Steady State ◽  
Total Hemispherical Emissivity

Anisotropic Polarized Emission of a Doped Silicon Lamellar Grating

2006 ◽  
Vol 129 (1) ◽  
pp. 11-16 ◽  
Author(s):  
F. Marquier ◽  
M. Laroche ◽  
R. Carminati ◽  
J.-J. Greffet
Keyword(s):  
Surface Plasmons ◽  
Angular Dependence ◽  
Thermal Emission ◽  
Azimuthal Angle ◽  
Radiative Cooling ◽  
Polarized Emission ◽  
Doped Silicon ◽  
Resonant Emission ◽  
Thermal Sources ◽  
Total Hemispherical Emissivity

Thermal emission of a doped silicon grating has been studied in the plane perpendicular to the grooves. We show how the excitation of surface plasmons produce a resonant emission weakly depending on the polarization and azimuthal angle. We analyze in detail the polarization and angular dependence of the emission out of the plane perpendicular to the grooves. Two kinds of thermal sources, directional and quasi-isotropic, are studied. They have been designed in a previous paper. We also compute the total hemispherical emissivity of these gratings. In addition we show that in applications such as radiative cooling, these sources are less efficient than other structures.

Total Hemispherical Emissivity of SS 316L with Simulated Very High Temperature Reactor Surface Conditions

2017 ◽  
Vol 198 (3) ◽  
pp. 293-305 ◽  
Author(s):  
Tristan S. Hunnewell ◽  
Kyle L. Walton ◽  
Sangita Sharma ◽  
Tushar K. Ghosh ◽  
Robert V. Tompson ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Conditions ◽  
Very High Temperature Reactor ◽  
High Temperature Reactor ◽  
Reactor Surface ◽  
Total Hemispherical Emissivity ◽  
Very High

Apparent Emissivity of Combustion Soot Aggregate Coating at High Temperature

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Tai Ran Fu ◽  
Ji Bin Tian ◽  
Hua Sheng Wang
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Room Temperature ◽  
Spectral Emissivity ◽  
Radiative Properties ◽  
Nickel Substrate ◽  
Soot Aggregate ◽  
Different Temperatures ◽  
Few Data ◽  
Total Hemispherical Emissivity

Soot aggregates frequently occur during combustion or pyrolysis of fuels. The radiative properties of soot aggregates at high temperature are important for understanding soot characteristics and evaluating heat transfer in combustion systems. However, few data for soot radiative properties at high temperature were available. This work experimentally investigated the apparent emissivity of the soot aggregate coating at high temperature using spectral and total hemispherical measurements. The soot aggregate coatings were formed on nickel substrates by a paraffin flame. The surface and inner morphology of the coatings were characterized by scanning electron microscope (SEM). The thickness of the coating was 30.16 μm so the contribution of the smooth nickel substrate to the apparent radiation from the coating could be neglected. The total hemispherical emissivity of the coating on the nickel substrate was measured using the steady-state calorimetric method at different temperatures. The spectral directional emissivity of the coating was measured for the wavelength of 0.38–16.0 μm at the room temperature. The measurements show that the total hemispherical emissivity decreases from 0.895 to 0.746 as the temperature increases from 438 K to 1052 K. The total hemispherical emissivity of the coating deposited on the nickel substrate is much larger than those of the nickel substrate and a nickel oxidization film. The measured spectral emissivity of the coating at the room temperature was used to theoretically calculate the total hemispherical emissivity at different temperatures by integration with respect to wavelength. The measured and calculated total hemispherical emissivities were similar, but their changes relative to temperature were completely opposite. This difference is due to the fact that the spectral emissivity of the coating is a function of temperature. The present results provide useful reference data for analyzing radiative heat transfer at high temperature of soot aggregates in combustion processes.

Total Hemispherical Emissivity of Potential Structural Materials for Very High Temperature Reactor Systems: Hastelloy X

2010 ◽  
Vol 172 (1) ◽  
pp. 88-100 ◽  
Author(s):  
Raymond K. Maynard ◽  
Tushar K. Ghosh ◽  
Robert V. Tompson ◽  
Dabir S. Viswanath ◽  
Sudarshan K. Loyalka
Keyword(s):  
High Temperature ◽  
Structural Materials ◽  
Hastelloy X ◽  
Very High Temperature Reactor ◽  
High Temperature Reactor ◽  
Total Hemispherical Emissivity ◽  
Very High
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