The use of the Monte Carlo method in radiative heat transfer is reviewed. The review covers surface-surface, enclosure, and participating media problems. Discussio. is included of research on the fundamentals of the method and on applications to surface-surface interchange in enclosures, exchange between surfaces with roughness characteristics, determination of configuration factors, inverse design, transfer through packed beds and fiber layers, participating media, scattering, hybrid methods, spectrally dependent problems including media with line structure, effects of using parallel algorithms, practical applications, and extensions of the method. Conclusions are presented on needed future work and the place of Monte Carlo techniques in radiative heat transfer computations

The Monte Carlo Method in Radiative Heat Transfer

A computer program using a variation of the Monte Carlo method was developed to predict radiative exchange factors in three-dimensional configurations with curved surfaces. The model allows for arbitrary emission, absorption, and reflection characteristics and for radiation exchange between surfaces as well as external irradiation through openings. It was shown that exchange factors can be determined efficiently by using the normal Monte Carlo method for closed configurations and/or high surface emissivities, while energy partitioning is vastly superior in the case of open configurations and/or low surface emissivities. Comparison with some experiments performed on the Space Shuttle heat rejection system demonstrates the model's accuracy as well as its superiority over a simplified diffuse-surface analysis, which requires similar amounts of computer time.

Three-dimensional radiative exchange factors for nongray, nondiffuse surfaces

Heat transfer—A review of 1971 literature

Energy redistributed and absorbed in the cavity produced by a high-intensity beam during drilling and welding is systematically and quantitatively investigated. The incident energy flux is assumed to be a realistic Gaussian distribution, and the cavity is idealized by a paraboloid of revolution having both specular and diffuse reflectivities. By using a Monte Carlo method, the results show that the energy absorbed by the cavity wall deviates markedly from the Gaussian distribution. Effects of the cavity depth-to-opening radius ratio, absorptivity, and specular reflectivity on the absorbed energy are presented. A comparison of incident energy fluxes of uniform and Gaussian distributions is also made.

Energy-beam redistribution and absorption in a drilling or welding cavity

The behavior of solar collector geometries designed to provide moderate concentration of solar flux is examined experimentally. The moderate concentration is achieved by using East--West oriented trapezoidal grooves with highly reflective sidewalls and a highly absorbant base plate. It is found, as predicted from previous analysis, that significant increases in collector efficiency are possible at the temperature required for supplying absorption air-conditioning systems. The experimental results verify the analysis. Concentration ratios from the measurements compare well with analytical predictions. Sidewall materials tested include back-surfaced glass and plexiglas mirrors and aluminum foil. Foil measurements are less consistent with predictions due to surface nonuniformities.

J. R. Howell

Papers

Radiative Transfer Between Surfaces in a Cavity With Collimated Incident Radiation: A Comparison of Analysis and Experiment