Estimation of flow field in natural convection with density stratification by local ensemble transform Kalman filter

Ishigaki, Masahiro*; Hirose, Yoshiyasu; Abe, Satoshi; Nagai, Toru*; Watanabe, Tadashi*

Fluids (Internet), 7(7), p.237_1 - 237_18, 2022/07

https://doi.org/10.3390/fluids7070237

Measurement of velocity and temperature profiles in boundary layer with steam condensation

Soma, Shu; Abe, Satoshi; Shibamoto, Yasuteru; Ishigaki, Masahiro*

Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 13 Pages, 2022/03

Numerical study on an interface compression method for the volume of fluid approach

Okagaki, Yuria; Yonomoto, Taisuke; Ishigaki, Masahiro; Hirose, Yoshiyasu

Fluids (Internet), 6(2), p.80_1 - 80_17, 2021/02

https://doi.org/10.3390/fluids6020080

LES-WALE simulation on two liquid mixing in the horizontal legs and downcomer; The Open-test condition in the TAMU-CFD benchmark (IBE-5)

Abe, Satoshi; Okagaki, Yuria; Ishigaki, Masahiro; Shibamoto, Yasuteru

Proceedings of OECD/NEA Workshop on Virtual CFD4NRS-8; Computational Fluid Dynamics for Nuclear Reactor Safety (Internet), 11 Pages, 2020/11

Application of immersed boundary method for jet flow in grating type structure

Hirose, Yoshiyasu; Ishigaki, Masahiro; Abe, Satoshi; Shibamoto, Yasuteru

Proceedings of International Topical Meeting on Advances in Thermal Hydraulics (ATH '20) (Internet), p.757 - 767, 2020/10

https://doi.org/10.13182/ATH2020-32837

CFD analysis of the CIGMA experiments on the heated JET injection into containment vessel with external surface cooling

Hamdani, A.; Abe, Satoshi; Ishigaki, Masahiro; Shibamoto, Yasuteru; Yonomoto, Taisuke

Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.5463 - 5479, 2019/08

Numerical simulation of natural circulation experiment under asymmetric cooldown using LSTF

Ishigaki, Masahiro; Watanabe, Tadashi*

Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 10 Pages, 2018/10

When coolant in one of the secondary side of steam generator (SG) is lost under some accident condition, the NC in the loop with the affected SG may terminate. Hence, the experiment was done in order to discuss the behavior of the natural circulation flow when the secondary side of the intact SG was depressurized stepwisely and that of the affected SG was empty of coolant. In this paper, we analyzed this NC experiment using the LSTF by the TRACE code. The objective of this analysis is to clarify the sensitivity of the code to the NC behavior. The calculated mass flow rate in the intact loop was slightly underestimated compared with the experimental result. On the other hand, the calculated mass flow rate in the affected loop was overestimated compared with the experimental result. In addition, we did the sensitivity analysis of the NC behavior in the case that the cooldown rate was changed.

Analyses of LSTF experiment and PWR plant for 5% cold-leg break loss of coolant accident

Watanabe, Tadashi*; Ishigaki, Masahiro*; Katsuyama, Jinya

Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 9 Pages, 2018/10

The analyses of LSTF experiment and PWR plant for 5% cold-leg break LOCA are performed using the RELAP5/MOD3.3 code. The discharge coefficient of critical flow model is determined so as to obtain the agreement of pressure transient between the LSTF experiment and the experimental analysis, and used for the PWR analysis. The characteristics of thermal-hydraulic phenomena in the experiment are shown to be simulated well by the two analyses. The decrease in core differential pressure during the loop-seal clearing is, however, underestimated by the two analyses, and the core heat up is not predicted. The loop flow rates are also underestimated by the two analyses. Although the duration of core heat up during the boil-off period is longer in the experimental analysis, the results of two analyses agree well, and the effect of scaling is found to be small between the experimental analysis and the PWR analysis.

Stratification breakup by a diffuse buoyant jet; The MISTRA HM1-1 and 1-1bis experiments and their CFD analysis

Abe, Satoshi; Studer, E.*; Ishigaki, Masahiro; Shibamoto, Yasuteru; Yonomoto, Taisuke

Nuclear Engineering and Design, 331, p.162 - 175, 2018/05

https://doi.org/10.1016/j.nucengdes.2018.01.050

RANS analysis with a dynamic model for turbulent Schmidt number () on density stratification erosion in a small rectangular vessel

Abe, Satoshi; Studer, E.*; Ishigaki, Masahiro; Shibamoto, Yasuteru; Yonomoto, Taisuke

Proceedings of 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17) (USB Flash Drive), 13 Pages, 2017/09