Numerical analysis of supersonic jet flow and dust transport induced by air ingress in a fusion reactor  

作　　者：Bu-Er Wang Shi-Chao Zhang Zhen Wang Jiang-Tao Jia Zhi-Bin Chen 

机构地区：[1]Institute of Nuclear Energy Safety Technology,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China [2]University of Science and Technology of China,Hefei 230026,China

出　　处：《Nuclear Science and Techniques》2021年第7期72-82,共11页核技术（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(No.51906249);National Key R&D Program of China(No.2019YFE0191600);President Foundation of Hefei Institute of Physical Science,Chinese Academy of Sciences(No.YZJJ2019QN21).

摘　　要：During a loss of vacuum accident(LOVA),the air ingress into a vacuum vessel(VV)may lead to radioactive dust resuspension,migration,and even explosion,thereby posing a great threat to the safe operation of future fusion reactors;thus,it is crucial to understand the flow characteristics and radioactive dust transport behavior induced by LOVA.However,only a few studies have identified the characteristics of the highly under-expanded jet flow at a scale of milliseconds during LOVA.Particularly,the occurrence and behavior of a Mach disk is yet to be captured in existing studies.In this study,we used a more advanced model with a finer mesh and adaptive mesh strategies to capture the Mach disk in a VV during LOVA.In detail,a computational fluid dynamics–discrete phase model one-way coupled multiphase approach was established using the computational fluid dynamics code ANSYS FLUENT and applied to the analysis during the first seconds of LOVA.The results showed that air ingress into the VV behaved like a highly free under-expanded jet at the initial stage and Mach disk was formed at~6 ms.Moreover,the flow field dramatically changed at the position of the Mach disk.The jet core before the Mach disk had a maximum velocity of~8 Mach with the corresponding lowest static pressure(~100 Pa)and temperature(few tens of K).The friction velocities in the lower part of the VV,which is an area of concern due to dust deposition,were generally larger than 15 m/s near the inlet region.Lastly,the crude prediction of the particle trajectories demonstrated the spiral trajectories of the dust following the air motion.Therefore,this study provided a basis for further safety analysis and accident prevention related to dust transport and explosion in future fusion reactors.

关 键 词：Supersonic jet Radioactive dust Loss of vacuum accident Mach disk Friction velocity 

分 类 号：TL61[核科学技术—核技术及应用]