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Kamiya, Tomohiro; Yoshida, Hiroyuki
Proceedings of the Symposium on Shock Waves in Japan (Internet), 7 Pages, 2024/03
We developed a ghost fluid method satisfying conservation laws to simulate steam explosions that can occur at the accident of a nuclear power plant. In the developed method, a first-order approximation is applied to interface effect regions, and a high-order approximation is applied to bulk regions. In other words, the algorithm of the developed method is not consistent. Therefore, we modify the way of getting ghost fluids and propose a comprehensive algorithm that applies a high-order approximation to interface effect regions. In the presentation, we will report the outlines and results of the numerical tests of it.
Kamiya, Tomohiro; Yoshida, Hiroyuki
Dai-37-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Rombunshu (Internet), 8 Pages, 2023/12
We developed a sharp-interface method satisfying a conservation law for a compressible two-phase flow. In this presentation, the outline and numerical test results of the developed method in multi-dimension were reported. The ghost fluid method does not cause numerical diffusion at a gas-liquid interface because difference between gas and liquid phases is avoided. It cannot satisfy the conservation law because cells in which liquid and gas coexist are not prepared although in fact an interface crosses a cell. Hence, we developed the ghost fluid method satisfying a conservation law by preparing cells in which liquid and gas coexist by VOF method. Multi-dimensional basic equations are solved by a split method which is one of the geometric VOF methods. We solved an underwater explosion problem and confirmed that gas bubble expansion and compressible wave propagation which are observed in the steam explosion can be represented and developed method satisfies the conservation law.
Kamiya, Tomohiro; Ono, Ayako; Tada, Kenichi; Akie, Hiroshi; Nagaya, Yasunobu; Yoshida, Hiroyuki; Kawanishi, Tomohiro
Proceedings of 29th International Conference on Nuclear Engineering (ICONE 29) (Internet), 8 Pages, 2022/11
JAEA started to develop the advanced reactor analysis code JAMPAN (JAEA advanced multi-physics analysis platform for nuclear systems). The current version of JAMPAN handles the continuous energy Monte Carlo code MVP and the detailed thermal-hydraulics analysis code for multiphase and multicomponent JUPITER. JAMPAN is designed to consider the extensibility and it does not depend on the analysis codes. All calculations in JAMAPAN are not directly connected. JAMPAN has data containers, and all input and output data of each analysis code are set in these data containers. JAMPAN will easily exchange the calculation codes and add the other calculations, e.g., structure calculation and irradiation calculation since the input and the output format of each code has no impact on the other calculation codes. The 4 by 4 pin-cell geometry was used as the demonstration calculation of JAMPAN and the physically reasonable calculation results were obtained.
Tada, Kenichi; Akie, Hiroshi; Kamiya, Tomohiro; Ono, Ayako; Nagaya, Yasunobu; Yoshida, Hiroyuki; Kawanishi, Tomohiro
no journal, ,
JAEA is developing the advanced neutronics/thermal-hydraulics coupling simulation system to improve the design and safety analysis of light water reactors. This presentation explains the coupling simulation system using a continuous energy Monte Carlo code MVP and a subchannel analysis code NASCA.
Kamiya, Tomohiro; Ono, Ayako; Tada, Kenichi; Akie, Hiroshi; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
JAEA is developing a platform JAMPAN for multiphysics simulation to realize advanced neutronics/thermal-hydraulics coupling simulation for improving design and safety of light water reactors. Flexibility and modularity are required for the platform; users can perform various multiphysics simulation by choosing combination of codes simulating various phenomena such as neutron transport, heat transfer/multi-phase flow, chemical reactions etc., and can easily replace and add independent codes. To meet these requirements, JAMPAN has a common data container and every data exchange between independent codes is conducted through the data container. In this presentation, we will explain an overview of JAMPAN and show results of neutronics/thermal-hydraulics simulation on 4
4 bundle system using MVP and JUPITER as an example of JAMPAN simulation.
Kamiya, Tomohiro; Yoshida, Hiroyuki
no journal, ,
We proposed equations of conservative form using a VOF function from a conservation law and the discretization method of these equations for liquid-gas two-phase compressible fluid simulations based on a sharp-interface model. The outline of these proposals and results of one-dimensional numerical tests will be reported.
Kamiya, Tomohiro
no journal, ,
no abstracts in English
Tada, Kenichi; Akie, Hiroshi; Kamiya, Tomohiro; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
We implemented the handling module for the subchannel analysis code NASCA on the multi-physics platform JAMPAN. This function is used for the neutronics/thermal-hydraulics coupling simulation. The MVP/NASCA coupling calculation on JAMPAN will be applied to the large-scale calculation e.g., a whole core analysis. The calculation results of JAMPAN were compared to those of the prototype simulation system IPACS. The calculation results of JAMPAN showed good agreement with those of IPACS.
Kamiya, Tomohiro; Ono, Ayako; Tada, Kenichi; Yamashita, Susumu; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
JAEA is developing a platform JAMPAN for multi-physics simulations to improve the design and safety of light water reactors. The Monte Carlo code MVP and the direct numerical simulation code for multi-phase flow JUPITER were coupled on this platform for detailed and high-fidelity neutronics/thermal-hydraulics coupling simulations. Because bubbles generated by boiling in a BWR have a large influence on neutron transport, phase change must be considered for the simulations. We will show simulation results of two-phase flow including phase change in this presentation. In these simulations, a temperature recovering method was used to estimate the amount of evaporation and condensation. We used an interface capture method as two-phase flow analysis method.
Yoshida, Hiroyuki; Kamiya, Tomohiro; Tada, Kenichi
no journal, ,
no abstracts in English
Kamiya, Tomohiro; Yoshida, Hiroyuki
no journal, ,
We developed a sharp-interface method satisfying a conservation law for a compressible two-phase flow. In this presentation, the outline and numerical test results of the developed method in multi-dimension were reported. The ghost fluid method does not cause numerical diffusion at a gas-liquid interface because difference between gas and liquid phases is avoided. It cannot satisfy the conservation law because cells in which liquid and gas coexist are not prepared although in fact an interface crosses a cell. Hence, we developed the ghost fluid method satisfying a conservation law by preparing cells in which liquid and gas coexist by VOF method. Multi-dimensional basic equations are solved by a split method which is one of the geometric VOF methods. We solved an underwater explosion problem and confirmed that gas bubble expansion and compressible wave propagation which are observed in the steam explosion can be represented and developed method satisfies the conservation law.
Tada, Kenichi; Kondo, Ryoichi; Kamiya, Tomohiro; Nagatake, Taku; Ono, Ayako; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
JAEA has developed a Python-based multi-physics platform JAMPAN. This platform has an HDF5 formatted JAMPAN data container. It connects calculation codes via this data container. The utilization of this container eliminates the dependence on the calculation code and enables us to easily exchange the coupling code. The first target of JAMPAN is a coupling of neutronics and thermal hydraulics codes to provide reference results of core analysis codes. The coupling of the other codes such as a fuel performance analysis code FEMAXI is future work. This presentation shows the overview of the JAMPAN platform.
8 single bundle assembly of BWRKamiya, Tomohiro; Ono, Ayako; Nagatake, Taku; Tada, Kenichi; Kondo, Ryoichi; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
JAEA aims to obtain reference solutions for reactor design codes by coupling the Monte Carlo code MVP and the multiphase and multi-component detailed thermal-hydraulic analysis code JUPITER on the multiphysics platform JAMPAN (JAEA Advanced Multi-Physics Analysis platform for Nuclear systems). For BWR, the thermal-hydraulic analysis code is required to consider boiling around fuel rods. Therefore, a thermal-hydraulic simulation of an 88 STEP-II single fuel assembly system was performed considering boiling using the temperature recovery method.
Tada, Kenichi; Kondo, Ryoichi; Kamiya, Tomohiro; Nagatake, Taku; Ono, Ayako; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
JAEA has developed the multi-physics platform JAMPAN. In the previous presentation, we demonstrated a BWR single fuel assembly calculation by the coupling calculation of the continuous energy Monte Carlo calculation code MVP and the subchannel analysis code NASCA. The final goal of the MVP/NASCA coupling calculation is the whole core analysis. To achieve this, we implemented the flow rate calibration function in JAMPAN for the MVP/NASCA coupling calculation of the BWR multi-fuel assembly geometry.
Kamiya, Tomohiro; Nagatake, Taku; Ono, Ayako; Tada, Kenichi; Kondo, Ryoichi; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
JAEA has developed a platform JAMPAN for multi-physics simulations, has improved a neutronics analysis code, and has improved and validated thermal-hydraulics analysis codes to improve the design and the safety of light water reactors. The objective is implementing the coupling modules between the neutronics code MVP and the thermal-hydraulics code JUPITER, and verifying the modules. A fuel bundle geometry under a normal operation condition of a BWR was used for the neutronics and thermal-hydraulics coupling simulation to verify the modules. In this presentation, we will explain how to send and receive data between MVP and JUPITER through JAMPAN and show the results of the neutronics/thermal-hydraulics coupling simulations using MVP and JUPITER.
