A multithreaded parallel upwind sweep algorithm for the SN transport equations discretized with discontinuous finite elements

• Published in: Nuclear science and techniques 2023-12, Vol.34 (12), p.229-241, Article 200
• Main Authors: Zong, Zhi-Wei, Cheng, Mao-Song, Yu, Ying-Chi, Dai, Zhi-Min
• Format: Article
• Language: English
• Subjects: Beam Physics; Nuclear Energy; Particle Acceleration and Detection; Particle and Nuclear Physics; Physics; Physics and Astronomy
• ISSN: 1001-8042; 2210-3147
• DOI: 10.1007/s41365-023-01355-4

The complex structure and strong heterogeneity of advanced nuclear reactor systems pose challenges for high-fidelity neutron-shielding calculations. Unstructured meshes exhibit strong geometric adaptability and can overcome the deficiencies of conventionally structured meshes in complex geometry modeling. A multithreaded parallel upwind sweep algorithm for S N transport was proposed to achieve a more accurate geometric description and improve the computational efficiency. The spatial variables were discretized using the standard discontinuous Galerkin finite-element method. The angular flux transmission between neighboring meshes was handled using an upwind scheme. In addition, a combination of a mesh transport sweep and angular iterations was realized using a multithreaded parallel technique. The algorithm was implemented in the 2D/3D S N transport code ThorSNIPE, and numerical evaluations were conducted using three typical benchmark problems: IAEA, Kobayashi-3i, and VENUS-3. These numerical results indicate that the multithreaded parallel upwind sweep algorithm can achieve high computational efficiency. ThorSNIPE, with a multithreaded parallel upwind sweep algorithm, has good reliability, stability, and high efficiency, making it suitable for complex shielding calculations.