View factor

Abstract: 1. Fundamentals of Thermal Radiation 2. Radiative Property Predictions from Electromagnetic Wave Theory 3. Radiative Properties of Real Surfaces 4. View Factors 5. Radiative Exchange Between Gray, Diffuse Surfaces 6. Radiative Exchange Between Partially-Specular Gray Surfaces 7. Radiative Exchange Between Nonideal Surfaces 8. Surface Radiative Exchange in the Presence of Conduction and Convection 9. The Equation of Radiative Transfer in Participating Media 10. Radiative Properties of Molecular Gases 11. Radiative Properties of Particulate Media 12. Radiative Properties of Semitransparent Media 13. Exact Solutions for One-Dimensional Gray Media 14. Approximate Solution Methods for One-Dimensional Media 15. The Method of Spherical Harmonics (PN-Approximation) 16. The Method of Discrete Ordinates (SN-Approximation) 17. The Zonal Method 18. The Treatment of Collimated Irradiation 19. The Treatment of Nongray Extinction Coefficients 20. The Monte Carlo Method for Thermal Radiation 21. Radiation Combined with Conduction and Convection 22. Inverse Radiative Heat Transfer A. Constants and Conversion Factors B. Tables for Radiative Properties of Opaque Surfaces C. Blackbody Emissive Power Table D. View Factor Catalogue E. Exponential Integral Functions F. Computer Codes Author Index Subject Index

Abstract: The 3-D view factor code VISRAD is used to both design high-energy density physics experiments, and to simulate the multi-dimensional radiation environment within target systems, i.e., hohlraums and associated components such as diagnostic holes, capsules, and backlighters. VISRAD target systems are built using a variety of geometric primitives, and surface removal algorithms (e.g., drilling holes in cylinders) can be employed to build complex targets. Laser beam parameters—power profiles, pointing, and focusing—can be specified for either individual beams or groups of beams. At present, the OMEGA and National Ignition Facility laser systems are supported by VISRAD. The use of multiple coordinate systems is supported so that target components can be positioned and oriented, and laser beams can be pointed, in the target chamber coordinate system or in the coordinate system of any target component. Radiation flux distributions about the target system are computed by solving a coupled set of power balance equations in which the emission from a given surface element in the target grid is coupled to all other surface elements. Accurate algorithms are used in computing the configuration (view factor) integrals. At any point in the grid, the time- and frequency-dependent flux incident onto that point can be viewed and/or written to a file to be used as input to radiation-hydrodynamics simulations. Energy source models include laser energy deposition—computed using 3-D ray-trace algorithms—and self-radiating target components. To aid designers in setting up targets, pointing beams, and viewing results, VISRAD has an easy-to-use graphical user interface and interactive 3-D graphics. The code has been designed for cross-platform use on Windows, Unix, and Mac OS X platforms.