Longwave band model for thermal radiation in climate studies

1992 ◽  
Vol 97 (D11) ◽  
pp. 11475 ◽  
Author(s):  
B. P. Briegleb
Keyword(s):  
Thermal Radiation ◽  
Band Model ◽  
Longwave Band ◽  
Climate Studies

Analysis of Flame Radiative Heat Transfer Using Large Eddy Simulation

2009 ◽  
Author(s):  
Zhenghua Yan ◽  
Bengt Sunden ◽  
Michael A. Delichatsios
Keyword(s):  
Heat Transfer ◽  
Thermal Radiation ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Soot Formation ◽  
Integral Model ◽  
Band Model ◽  
Grid Turbulence ◽  
Radiation Property ◽  
Large Eddy

A series of comprehensive large eddy simulations of non-premixed turbulent hydrocarbon flames of different sizes in a typical fire scenario have been carried out to compute the flame radiative heat transfer. In the simulation, considerations include the modelling of sub-grid turbulence, turbulent combustion, soot formation, thermal radiation and interactive heat transfer inside solid walls, etc. The instantaneous thermal radiation was calculated using the discrete transfer method with the radiation property evaluated by both an approximated fast narrow band model and an integral model. Simulation was validated against experimental data. Flame radiation heat transfer was compared for flames of different sizes. The effect of thermal radiation property evaluation model on calculation of radiation and the role of thermal radiation in total heat transfer are analyzed.

Thermal Radiation Properties of Acetylene

1985 ◽  
Vol 107 (4) ◽  
pp. 943-948 ◽  
Author(s):  
M. A. Brosmer ◽  
C. L. Tien
Keyword(s):  
Absorption Coefficient ◽  
Thermal Radiation ◽  
Narrow Band ◽  
Wide Band ◽  
Band Model ◽  
Radiation Properties ◽  
Wide Band Model ◽  
Combination Bands ◽  
Total Emissivity

The spectral absorptivities of the ν3 and ν5 fundamental and the ν4 + ν5 combination bands of acetylene have been measured at low resolution for temperatures between 290 and 600 K. These measurements allow the determination of spectral-mean (narrow-band) parameters for the three bands based on the Elsasser and Goody models and the correlation of the band absorptance data using the Edwards exponential wide-band model. Charts for the total emissivity and Planck mean absorption coefficient have been developed for acetylene based on the wide-band parameters.

SHEAR BAND OBSERVATIONS AND DERIVATIONS OF REQUIREMENTS FOR A SHEAR BAND MODEL

1985 ◽  
Vol 46 (C5) ◽  
pp. C5-273-C5-282
Author(s):  
L. Seaman ◽  
D. R. Curran ◽  
D. C. Erlich ◽  
T. Cooper ◽  
O. Dullum
Keyword(s):  
Shear Band ◽  
Band Model

Characterizing the convective heat exchange with plastic shading nets under natural arid conditions

2019 ◽  
pp. 11-20
Author(s):  
Ahmed M Abdel-Ghanya ◽  
Ibrahim M Al-Helal
Keyword(s):  
Wind Speed ◽  
Thermal Radiation ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Convective Heat Exchange ◽  
Radiative Properties ◽  
Wooden Frame ◽  
Arid Conditions ◽  
Air Temperatures ◽  
Radiation Fluxes

Plastic nets are extensively used for shading purposes in arid regions such as in the Arabian Peninsula. Quantifying the convection exchange with shading net and understanding the mechanisms (free, mixed and forced) of convection are essential for analyzing energy exchange with shading nets. Unlike solar and thermal radiation, the convective energy, convective heat transfer coefficient and the nature of convection have never been theoretically estimated or experimentally measured for plastic nets under arid conditions. In this study, the convected heat exchanges with different plastic nets were quantified based on an energy balance applied to the nets under outdoor natural conditions. Therefore, each net was tacked onto a wooden frame, fixed horizontally at 1.5-m height over the floor. The downward and upward solar and thermal radiation fluxes were measured below and above each net on sunny days; also the wind speed over the net, and the net and air temperatures were measured, simultaneously. Nets with different porosities, colors and texture structures were used for the study. The short and long wave’s radiative properties of the nets were pre-determined in previous studies to be used. Re and Gr numbers were determined and used to characterize the convection mechanism over each net. The results showed that forced and mixed convection are the dominant modes existing over the nets during most of the day and night times. The nature of convection over nets depends mainly on the wind speed, net-air temperature difference and texture shape of the net rather than its color and its porosity.

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