Open AccessThermo-fluid analyses for UCN cryogenic system
Author(s) -
Takahiro Okamura,
S. Kawasaki
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/755/1/012141
Subject(s) - heat exchanger , superfluid helium 4 , turbulence , superfluidity , fluid dynamics , cryogenics , helium , working fluid , boiling , flow (mathematics) , liquid helium , materials science , mechanics , physics , nuclear engineering , thermodynamics , condensed matter physics , atomic physics , engineering
The TUCAN collaboration is now developing the new cryogenic system for ultra-cold neutrons experiments (UCN). This cryogenic system requires superfluid helium (He II) around 0.8 K to 1.15 K because cold neutrons are down-scattered by isopure He II with such temperature range to become UCN. Dynamic heat load applied to He II during UCN production will be as high as approximately 10 W. In order to satisfy such requirements, not only 4 He but also 3 He has to be circulated through the cryogenic system. There are sixteen heat exchangers for 4 He and 3 He. In order to design these heat exchangers properly, thermo-fluid simulations are carried out. Some simulations of them are nontrivial because they include film boiling phenomena in superfluid, molecular gas dynamics effect, transition from single phase flow to two phase flow and discrimination of such kinds of the complicated flow behavior. In addition, Time dependent thermo-fluid behaviors of He-II are also simulated using two fluid model and superfluid turbulent model to clarify the He II behavior. In this presentation, the simulation schemes and some results will be discussed.