MIXED-CONVECTION AND THERMAL RADIATION HEAT TRANSFER IN A THREE-DIMENSIONAL ASYMMETRICALLY HEATED VERTICAL CHANNEL

Measurements were made of the combined natural convection and radiation heat transfer from a horizontal finned tube situated in a vertical channel open at the top and bottom. In one set of experiments, both walls of the channel were heavily insulated, while in a second set of experiments, one of the insulated walls was replaced by an uninsulated metallic sheet. In general, the heat transfer coefficients were found to be lower with the metal wall in place, but only moderately. With the finned tube situated at the bottom of the channel, the differences in the heat transfer coefficients corresponding to the two types of walls were only a few percent. When the tube was positioned at the mid-height of the channel, larger differences were encountered, but in the practical range of Rayleigh numbers, the differences did not exceed 5 percent.

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A probabilistic study of the influence of parameter uncertainty on thermal radiation heat transfer

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2009.12.004 ◽

2010 ◽

Vol 53 (7-8) ◽

pp. 1461-1472 ◽

Cited By ~ 10

Author(s):

M.M.R. Williams

Keyword(s):

Heat Transfer ◽

Thermal Radiation ◽

Parameter Uncertainty ◽

Radiation Heat Transfer ◽

Radiation Heat ◽

Probabilistic Study

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Simulation of Radiation Heat Transfer of Three Dimensional Participating Media by Radiative Exchange Method

Heat Transfer: Volume 3 ◽

10.1115/ht2008-56076 ◽

2008 ◽

Author(s):

Mohammad Hadi Bordbar ◽

Timo Hyppa¨nen

Keyword(s):

Heat Transfer ◽

Balance Equation ◽

Radiation Heat Transfer ◽

Three Dimensional ◽

Radiation Balance ◽

Scattering Media ◽

Radiation Heat ◽

Exchange Method ◽

Participating Media ◽

Radiative Exchange

This paper describes the theoretical bases of the Radiative Exchange Method, a new numerical method for simulating radiation heat transfer. By considering radiative interaction between all points of the geometry and solving the radiation balance equation in a mesh structure coarser than the structure used in computational fluid flow calculation, this method is able to simulate radiative heat transfer in arbitrary 3D space with absorbing, emitting and scattering media surrounded by emitting, absorbing and reflecting surfaces. A new concept is introduced, that of the exchange factors between the different elements that are necessary for completing the radiative balance equation set. Using this method leads to a set of algebraic equations for the radiative outgoing power from each coarse cell being produced and the result of this set of equations was then used to calculate the volumetric radiative source term in the fine cell structure. The formulation of the exchange factor for a three-dimensional state and also a mesh size analysis that was conducted to optimize the accuracy and runtime are presented. The results of this model to simulate typical 3D furnace shape geometry, is verified by comparison with those of other numerical methods.

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