Total hemispherical apparent radiative properties of the infinite V-groove with specular reflection
| Autor: | Matthew R. Jones, Rydge B. Mulford, Nathan S. Collins, Brian D. Iverson, Michael S. Farnsworth |
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| Rok vydání: | 2018 |
| Předmět: |
Fluid Flow and Transfer Processes
Materials science 020209 energy Mechanical Engineering 02 engineering and technology Molar absorptivity Condensed Matter Physics Collimated light Isothermal process Computational physics Thermal 0202 electrical engineering electronic engineering information engineering Radiative transfer Emissivity Specular reflection Distributed ray tracing |
| Zdroj: | International Journal of Heat and Mass Transfer. 124:168-176 |
| ISSN: | 0017-9310 |
| DOI: | 10.1016/j.ijheatmasstransfer.2018.03.041 |
| Popis: | Multiple reflections in a cavity geometry augment the emission and absorption of the cavity opening relative to a flat surface in a phenomenon known as the cavity effect. The extent of the cavity effect is quantified using apparent absorptivity and apparent emissivity. Analysis of complicated thermal systems is simplified through application of apparent radiative properties to cavity geometries. The apparent radiative properties of a specularly-reflecting, gray, isothermal V-groove have been derived analytically, but these results have not been validated experimentally or numerically. Additionally, the model for apparent absorptivity of an infinite V-groove subjected to partial illumination in the presence of collimated irradiation is not available. In this work, the following existing models for a specularly-reflecting V-groove are collected into a single source: (1) the apparent absorptivity of a diffusely irradiated V-groove, (2) the apparent emissivity of an isothermal V-groove and (3) the apparent absorptivity of a V-groove subject to collimated irradiation with full-illumination. Further, a new analytical model is developed to predict the apparent absorptivity of an infinite V-groove subject to collimated irradiation with partial-illumination. A custom, Monte Carlo ray tracing solver is used to predict the apparent radiative properties for all cases as a means of numerical verification by comparing the ray tracing data with the results from the new model in this work and the previously existing models. For diffuse irradiation, the analytical model and ray tracing data show excellent agreement with an average discrepancy of 4.4 × 10−4, verifying the diffuse-irradiation analytical model. Similar agreement is found for collimated irradiation, where the full and partial illumination models indicate average discrepancies of 4.9 × 10−4 and 4.6 × 10−4 when compared with ray tracing data. |
| Databáze: | OpenAIRE |
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