Parallel computation of radiation view factors between two arbitrarily oriented surfaces
✍ Scribed by Kuppurao, S. ;Tantra, I. ;Derby, J. J.
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 517 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1069-8299
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✦ Synopsis
Two implementations for parallel computation of radiation heat transfer view factors are formulated and tested for a model problem. Using a sufficiently large number of processors and a suitable communications paradigm, the solution time for the problem considered here scales linearly with the number of surface elements in the parallel implementation rather than the quadratic scaling obtained using a serial approach. For larger problems, significantly shorter solution times are obtained using the massively parallel Connection Machine 5 than those obtained on a single processor of the Cray C-90, a traditional vector supercomputer. Parallel performance was degraded for implementations using too few processors or data layouts leading to inefficient processor communication.
KEY WORDS view factor; radiation; parallel computation; heat transfer
1. BACKGROUND
Thermal radiation assumes great importance in high temperature engineering systems and presents significant challenges for analysis due to the strongly non-linear dependence of thermal radiation on the temperature field and the sensitive coupling of system geometry to radiant exchange among surfaces. Therefore, efficient numerical methodologies are needed for analysis of this mode of heat transfer. In prior work, we have developed novel finite element formulations to accurately calculate both radiation through participating media' and radiant exchange among surfaces in an enclosure.2 Here, rather than presenting new formulations for radiant heat transfer, we focus on novel implementations of existing methods on a modern, massively parallel supercomputer. We demonstrate that significant benefits, notably solution times which scale as N rather than N 2 (where N is the number of enclosure elements), can be obtained by judicious implementation on a data parallel computer.
2. METHODOLOGY
We consider the calculation of view factors, which are needed in classical net radiation methods for enclosure heat transfer. Siege1 and Howell3 provide an excellent discourse on these methods, and Kuppurao and Derby have developed techniques which allow for higher-order extension of these approaches. Often, the calculation of view factors is a significant, sometimes even the dominant, portion of the total computational expense for a radiant heat transfer problem.