2026-02-12 日本原子力研究開発機構
図1 従来の非圧縮性モデルと新しい弱圧縮性モデルを利用した気液二相流解析の比較
＜関連情報＞
- https://www.jaea.go.jp/02/press2025/p26021201/
- https://www.sciencedirect.com/science/article/pii/S0021999125008162
気液二相流のための半暗黙的弱圧縮性ソルバー A semi-implicit weakly compressible solver for gas-liquid two-phase flows
Kenta Sugihara, Naoyuki Onodera, Yasuhiro Idomura, Yos Panagaman Sitompul, Susumu Yamashita
Journal of Computational Physics Available online: 22 December 2025
DOI:https://doi.org/10.1016/j.jcp.2025.114534
Highlights
- Efficient calculation methods for gas-liquid two-phase flows, a semi-implicit compressible method (SI-C) and a semi-implicit weakly compressible method (SI-WC), are proposed based on the compressible Navier-Stokes equations.
- SI-C formulates the pressure Poisson-type equation from the compressible fluid equations, reducing iterations compared to incompressible methods.
- SI-WC employs a weakly compressible semi-implicit approach with an artificial sound speed, further decreasing the computational cost.
- Achieves computational efficiency while maintaining accuracy comparable to conventional incompressible methods.
- Validated through dam-breaking, single bubble rise, single-phase pipe flow, and bubble flow simulations in a circular tube.
Abstract
We propose a new gas-liquid two-phase fluid calculation method that improves computational efficiency compared with the conventional incompressible method (Incompressible). The methods are called the semi-implicit compressible method (SI-C) and the semi-implicit weakly compressible method (SI-WC). SI-C improves the convergence of the iterative solver by computing the pressure Poisson-type equation derived from the compressible fluid equation. In SI-WC, the number of iterations can be further reduced by computing a weakly compressible Poisson-type equation that uses an artificial sound speed controlled by the Mach number. The validity of the proposed method was verified by dam breaking problems and bubbly flow analysis, and comparative verification showed that compared to Incompressible, SI-C and SI-WC accelerate the pressure Poisson-type equation solver by a factor of two and four, respectively, while achieving almost the same solutions.
