New adaptive differencing strategy in the PENTRAN 3-d parallel S{sub n} code
- Pennsylvania State Univ., University Park, PA (United States)
It is known that three-dimensional (3-D) discrete ordinates (S{sub n}) transport problems require an immense amount of storage and computational effort to solve. For this reason, parallel codes that offer a capability to completely decompose the angular, energy, and spatial domains among a distributed network of processors are required. One such code recently developed is PENTRAN, which iteratively solves 3-D multi-group, anisotropic S{sub n} problems on distributed-memory platforms, such as the IBM-SP2. Because large problems typically contain several different material zones with various properties, available differencing schemes should automatically adapt to the transport physics in each material zone. To minimize the memory and message-passing overhead required for massively parallel S{sub n} applications, available differencing schemes in an adaptive strategy should also offer reasonable accuracy and positivity, yet require only the zeroth spatial moment of the transport equation; differencing schemes based on higher spatial moments, in spite of their greater accuracy, require at least twice the amount of storage and communication cost for implementation in a massively parallel transport code. This paper discusses a new adaptive differencing strategy that uses increasingly accurate schemes with low parallel memory and communication overhead. This strategy, implemented in PENTRAN, includes a new scheme, exponential directional averaged (EDA) differencing.
- OSTI ID:
- 426395
- Report Number(s):
- CONF-961103-; ISSN 0003-018X; TRN: 96:006307-0117
- Journal Information:
- Transactions of the American Nuclear Society, Vol. 75; Conference: Winter meeting of the American Nuclear Society (ANS) and the European Nuclear Society (ENS), Washington, DC (United States), 10-14 Nov 1996; Other Information: PBD: 1996
- Country of Publication:
- United States
- Language:
- English
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