Heat Transfer by Simultaneous Conduction and Radiation in an Absorbing Medium

Abstract

Heat transfer by simultaneous conduction and radiation in a thermal radiation absorbing and emitting medium is considered. Consideration is given to a one-dimensional system consisting of two, diffuse, nonblack, infinite, isothermal, parallel plates separated by a finite distance. The space between the plates is filled with a thermal radiation absorbing and emitting medium. The problem is formulated in terms of a nonlinear integro-differential equation and the solution is obtained by reducing it to a nonlinear integral equation. The numerical results are obtained by an iterative method. The temperature distributions and heat transfer are calculated. Two approximate methods for formulating radiant heat-transfer problems are presented and comparisons of the results are made with the most exact solution.

Numerical quantification of coupling effects for radiation-conduction heat transfer in participating macroporous media: Investigation of a model geometry

“…Fig. 4 shows the comparison of our results for the temperature profile, compared to the results obtained in Viskanta and Grosh [29]. The root mean square deviations remain below 2 Á 10 À3 for all cases.…”

“…The radiation-conduction coupling was verified using results from Viskanta and Grosh [29], considering the case of two infinite, parallel black plates filled with a participating medium. The results in [29] are given for different conduction-toradiation parameters N ¼ k Á b=ð4r B n 2 T 3 Þ (N = 0, 0.01, 0.1).…”

“…The results in [29] are given for different conduction-toradiation parameters N ¼ k Á b=ð4r B n 2 T 3 Þ (N = 0, 0.01, 0.1). Again perfect specular mirrors were used in the directions of vanishing gradients to mimic the one-dimensional setup of the reference problem.…”

“…The root mean square deviations remain below 2 Á 10 À3 for all cases. Some deviation is expected due to the digitization of the curves from [29] that was carried out with the software ''Engauge digitizer". Fig.…”

Influence of Punch Density and Fiber Blends on Thermal Conductivity on Nonwoven

“…Viskanta [2] stated that due to interactions, these mechanisms, strictly speaking, are not separable. Many investigators in this field have studied these mechanisms, their interactions, and relative contributions [3][4][5].…”