Radiation conductivity for a random void-solid medium with diffusely reflecting surfaces

Wolf, Jeffrey R.; Tseng, J. W. C.; Strieder, William

doi:10.1016/0017-9310(90)90170-y

Cited by 6 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If greater accuracy is needed, including the case of paths with two successive surface scatterings will provide improvements. A variational principle based on the radiosity contains the implicit sum over all orders of diffuse scattering and easily deals with smaller ε s values. Such a variational upper bound principle exists, works well at higher porosities, and is probably the best option to tighten the ε eff upper bounds at lower fiber surface emissivities and higher void fractions …”

Section: Discussionmentioning

confidence: 99%

Fiber Bed Effective Emissivities from Multiple-Scattering Calculations

Strieder

2004

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

The effective emissivity of a random fiber bed is a thermodynamic coefficient of importance for high-temperature radiation heat transfer. A multiple-scattering theory is developed that provides complementary (i.e., same scattering order) upper and lower bounds for the fiber bed emissivity. An attractive feature of this method is that this pair of bounds comes from the evaluation of one integral. Results for single-scattering bounds include analytical estimates with rigorous error bounds for all porosities, local fiber surface emissivities, and several representative bed edge random fiber arrangements, i.e., all fibers perpendicular and all fibers parallel to the bed edge. The estimates are tight for fiber surface emissivities above 0.5 at any porosity or for all fiber surface emissivities at low bed porosities. The analytical, single-scattering results provide a parametric study of the fiber bed effective emissivity enhancement above the local fiber surface emissivity for all fiber surface emissivities, porosities, and two limiting fiber bed structures. The largest enhancement (33.4%) is found at the midrange of the fiber emissivity values and in the limit of unit void fraction for fibers oriented perpendicular to the bed edge surface.

show abstract

Section: Discussionmentioning

confidence: 99%