Surface Temperature Measurement Using Infrared Radiometer by Applying a Pseudo-Gray-Body Approximation: Estimation of Radiative Property for Metal Surface

1996 ◽  
Vol 118 (1) ◽  
pp. 73-78 ◽  
Author(s):  
T. Inagaki ◽  
Y. Okamoto
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Temperature Measurement ◽  
Metal Surfaces ◽  
Radiative Properties ◽  
Two Dimensional ◽  
Visualization Technique ◽  
Surface Temperature Measurement ◽  
Infrared Radiometer

The visualization technique using an infrared radiometer has been widely used to estimate a two-dimensional temperature distribution on a surface. We have previously proposed various characteristics of the radiative properties for nonmetal surfaces on which the gray-body approximation can be used. However, the gray-body approximation can not be applied to glossy metal surfaces, because the influence of the reflected energy on the temperature measurement becomes severe. A pseudo-gray-body approximation is therefore proposed to estimate a temperature field on metal surfaces and its applicability is confirmed using an infrared radiometer with three detection wavelength bands.

An analytical solution of a two-dimensional temperature field in a hollow cylinder under a time periodic boundary condition using Fourier series

2009 ◽  
Vol 223 (8) ◽  
pp. 1889-1901 ◽  
Author(s):  
G Atefi ◽  
M A Abdous ◽  
A Ganjehkaviri ◽  
N Moalemi
Keyword(s):  
Boundary Condition ◽  
Temperature Field ◽  
Fourier Series ◽  
Temperature Distribution ◽  
Analytical Solution ◽  
Hollow Cylinder ◽  
Periodic Boundary Condition ◽  
Periodic Boundary ◽  
Separation Of Variables ◽  
Two Dimensional

The objective of this article is to derive an analytical solution for a two-dimensional temperature field in a hollow cylinder, which is subjected to a periodic boundary condition at the outer surface, while the inner surface is insulated. The material is assumed to be homogeneous and isotropic with time-independent thermal properties. Because of the time-dependent term in the boundary condition, Duhamel's theorem is used to solve the problem for a periodic boundary condition. The periodic boundary condition is decomposed using the Fourier series. This condition is simulated with harmonic oscillation; however, there are some differences with the real situation. To solve this problem, first of all the boundary condition is assumed to be steady. By applying the method of separation of variables, the temperature distribution in a hollow cylinder can be obtained. Then, the boundary condition is assumed to be transient. In both these cases, the solutions are separately calculated. By using Duhamel's theorem, the temperature distribution field in a hollow cylinder is obtained. The final result is plotted with respect to the Biot and Fourier numbers. There is good agreement between the results of the proposed method and those reported by others for this geometry under a simple harmonic boundary condition.

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