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
Corresponding author, firstname.lastname@example.org
Scan for full text
Bu-Er Wang, Shi-Chao Zhang, Zhen Wang, et al. Numerical analysis of supersonic jet flow and dust transport induced by air ingress in a fusion reactor. [J]. Nuclear Science and Techniques 32(7):73(2021)
Bu-Er Wang, Shi-Chao Zhang, Zhen Wang, et al. Numerical analysis of supersonic jet flow and dust transport induced by air ingress in a fusion reactor. [J]. Nuclear Science and Techniques 32(7):73(2021) DOI： 10.1007/s41365-021-00912-z.
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, was 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.
Supersonic jetRadioactive dustLoss of vacuum accidentMach diskFriction velocity
J. Ongena, R. Koch, R. Wolf et al., Magnetic-confinement fusion. Nature Physics 12, 398-410 (2016). doi: 10.1038/nphys3745http://doi.org/10.1038/nphys3745
J.P. Sharpe, D.A. Petti, H.W. Bartels, A review of dust in fusion devices: Implications for safety and operational performance. Fusion Engineering Design, 63-64:153-163 (2002). doi: 10.1016/S0920-3796(02)00191-6http://doi.org/10.1016/S0920-3796(02)00191-6
A. Rondeau, S. Peillon, A. Roynette et al., Characterization of dust particles produced in an all-tungsten wall tokamak and potentially mobilized by airflow. Journal of Nuclear Materials 463:873-876 (2015). doi: 10.1016/j.jnucmat.2014.12.051http://doi.org/10.1016/j.jnucmat.2014.12.051
G. Mazzini, T. Kaliatka, M.T. Porfiri, Tritium and dust source term inventory evaluation issues in the European DEMO reactor concepts. Fusion Engineering and Design 146:510-513 (2019). doi: 10.1016/j.fusengdes.2019.01.008http://doi.org/10.1016/j.fusengdes.2019.01.008
G. Caruso, M. Nobili, L. Ferroni, Modelling of dust resuspension in tokamak devices during an air inflow event. Journal of Fusion Energy 34(5): 1039-1050 (2015). doi: 10.1007/s10894-015-9921-8http://doi.org/10.1007/s10894-015-9921-8
Y. Wu, Z. Chen, L. Hu et al., Identification of safety gaps for fusion demonstration reactors. Nature Energy 1:16154 (2016). doi: 10.1038/nenergy.2016.154http://doi.org/10.1038/nenergy.2016.154
M. Lukacs, L.G. Williams, Nuclear safety issues for fusion power plants. Fusion Engineering and Design 150:111377 (2020). doi: 10.1016/j.fusengdes.2019.111377http://doi.org/10.1016/j.fusengdes.2019.111377
Y. Xu, S. Liu, X. Ma et al., Numerical simulation of airflow characteristics during the loss of vacuum accident of CFETR. International Journal of Hydrogen Energy 43(24):11160-11172 (2018). doi: 10.1016/j.ijhydene.2018.04.228http://doi.org/10.1016/j.ijhydene.2018.04.228
S. Paci, N. Forgione, F. Parozzi et al., Bases for dust mobilization modelling in the light of STARDUST experiments. Nuclear Engineering & Design 235(10-12):1129-1138 (2005). doi: 10.1016/j.nucengdes.2005.01.015http://doi.org/10.1016/j.nucengdes.2005.01.015
L.A. Poggi, A. Malizia, J.F. Ciparisse et al., First experimental campaign to demonstrate STARDUST-Upgrade facility diagnostics capability to investigate lova conditions. Journal of Fusion Energy, 34(6):1320-1330 (2015). doi: 10.1007/s10894-015-9964-xhttp://doi.org/10.1007/s10894-015-9964-x
L.A. Poggi, A. Malizia, J.F. Ciparisse et al., STARDUST-U experiments on fluid-dynamic conditions affecting dust mobilization during LOVAs. Journal of Instrumentation 11(07): C07012 (2016). doi: 10.1088/1748-0221/11/07/C07012http://doi.org/10.1088/1748-0221/11/07/C07012
I. Lupelli, P. Gaudio, M. Gelfusa et al. Numerical study of air jet flow field during a loss of vacuum. Fusion Engineering & Design 89(9-10):2048-2052 (2014). doi: 10.1016/j.fusengdes.2014.03.064http://doi.org/10.1016/j.fusengdes.2014.03.064
P. Gaudio, A. Malizia, L. Lupelli, RNG k-ε modelling and mobilization experiments of loss of vacuum in small tanks for nuclear fusion safety applications. International Journal of Systems Engineering, Applications and Development. 5(3): 287-305 (2011).
T. Gélain, A. Rondeau, S. Peillon et al., CFD modelling of the wall friction velocity field in the ITER tokamak resulting from airflow during a loss of vacuum accident—Consequences for particle resuspension. Fusion Engineering Design 100:87-99 (2015) doi: 10.1016/j.fusengdes.2015.04.043http://doi.org/10.1016/j.fusengdes.2015.04.043
J.F. Ciparisse, R. Rossi, A. Malizia et al., 3D Simulation of a Loss of Vacuum Accident (LOVA) in ITER (International Thermonuclear Experimental Reactor): Evaluation of static pressure, mach number, and friction velocity. Energies, 11(4): 856 (2018). doi: 10.3390/en11040856http://doi.org/10.3390/en11040856
F. Feuillebois, F. Gensdarmes, T. Gelain, Particle behavior close to the lower wall of a tokamak type geometry during a loss of vacuum accident. Fusion Engineering and Design 153, 111500 (2020). doi: 10.1016/j.fusengdes.2020.111500http://doi.org/10.1016/j.fusengdes.2020.111500
Y.Y. Xu, S.L. Liu, X.M. Cheng et al., Numerical analysis of loss of vacuum accident (LOVA) and preliminary discussion about dust resuspension for CFETR. Fusion Engineering and Design 143:82-90 (2019). doi: 10.1016/j.fusengdes.2019.03.159http://doi.org/10.1016/j.fusengdes.2019.03.159
L.L. Tong, Numerical analysis of the dust distribution during LOVA. Annals of Nuclear Energy, 87:454-461 (2016). doi: 10.1016/j.anucene.2015.09.025http://doi.org/10.1016/j.anucene.2015.09.025
T. Gelain, F. Gensdarmes, S. Peillon et al., CFD modelling of particle resuspension in a toroidal geometry resulting from airflows during a loss of vacuum accident (LOVA). Fusion Engineering and Design 151, 111386 (2020). doi: 10.1016/j.fusengdes.2019.111386http://doi.org/10.1016/j.fusengdes.2019.111386
J. F. Daunenhofer and J. R. Baron, Grid Adaption for the 2D Euler equations. Technical Report AIAA-85-0484. American Institute of Aeronautics and Astronautics, 1985.
D. Maisonnier, I. Cook, S. Pierre et al., The European power plant conceptual study. Fusion Engineering and Design 75,1173-1179 (2005). doi: 10.1016/j.fusengdes.2005.06.095http://doi.org/10.1016/j.fusengdes.2005.06.095
D. Fang, L.F. Li, J. Li et al., Full-scale numerical study on the thermal-hydraulic characteristics of steam-water separation system in an advanced PWR UTSG. Part two: Droplets separation process. Progress in Nuclear Energy, 118: 103139 (2020). doi: 10.1016/j.pnucene.2019.103139http://doi.org/10.1016/j.pnucene.2019.103139
A. Zappatore, A. Froio, G.A. Spagnuolo et al., 3D transient CFD simulation of an in-vessel loss-of-coolant accident in the EU DEMO fusion reactor. Nuclear Fusion, 60(12):126001 (2020). doi: 10.1088/1741-4326/abac6bhttp://doi.org/10.1088/1741-4326/abac6b
E. Franquet, V. Perrier, S. Gibout et al. Free underexpanded jets in a quiescent medium: A review. Progress in Aerospace Sciences, 77:25-53 (2015). doi: 10.1016/j.paerosci.2015.06.006http://doi.org/10.1016/j.paerosci.2015.06.006
L. Schiller, A. Naumann, A drag coefficient correlation. Z. Ver. Deutsch. Ing 77, 318-320 (1935).
R. Rossi, P. Gaudio, L. Martellucci et al. Numerical simulations of radioactive dust particle releases during a Loss Of Vacuum Accident in a nuclear fusion reactor. Fusion Engineering and Design, 163, 112161 (2021). doi: 10.1016/j.fusengdes.2020.112161http://doi.org/10.1016/j.fusengdes.2020.112161