Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Ishigaki, Masahiro; Watanabe, Tadashi; Nakamura, Hideo
Proceedings of OECD/NEA and IAEA Workshop on Experimental Validation and Application of CFD and CMFD Codes in Nuclear Reactor Technology (CFD4NRS-4) (CD-ROM), 11 Pages, 2012/09
In this research, two-phase critical flow with the phase change in the Super Moby Dick convergent-divergent nozzle is analyzed numerically by the CFD code FLUENT, and we discuss the performance of the numerical code by comparing the mass flow rates, pressure and void fractions by the numerical simulations with those values by the experiments. The cavitation model is applied together with the evaporation-condensation model. The estimations of mass flow rate agree with the experimental results for the low axial pressure difference. On the other hand, the mass flow rates are under-estimated when the axial pressure difference is high. It is found that the mass flow rate is improved much by taking into account the effect of the wall vapor generation.
Tanaka, Masaaki
Proceedings of OECD/NEA and IAEA Workshop on Experimental Validation and Application of CFD and CMFD Codes in Nuclear Reactor Technology (CFD4NRS-4) (CD-ROM), 16 Pages, 2012/09
Thermal fatigue on the structure caused by thermal striping phenomena is one of the significant issues in design and safety of fast breeder reactors. A numerical simulation code MUGTHES has been developed to predict fluid mixing phenomena and thermal response in structure. Uncertainty quantification in V&V process for the thermal-hydraulics analysis module was examined with simple laminar flow problems according to the existing guidelines and that of the structure heat conduction analysis module including conjugate heat transfer model was also done for theoretical unsteady heat conduction problems as verification. After the verification, the MUGTHES code was validated for a practical fluid-structure thermal interaction problem in T-junction piping system and applicability of the code to the thermal fatigue issue was confirmed.