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Temperature and current sensitivity extraction of optical superconducting transition-edge sensors based on a two-fluid model

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Chinese Physics B 2021年第9期30卷 594-598页

作者： Yue Geng Pei-Zhan Li Jia-Qiang Zhong Wen Zhang Zheng Wang Wei Miao Yuan Ren Sheng-Cai Shi Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China University of Science and Technology of China Hefei 230026China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210023China

Optical superconducting transition-edge sensor(TES)has been widely used in quantum information,biological imaging,and fluorescence microscopy owing to its high quantum efficiency,low dark count,and photon number resolving *** temperature sensitivity(α_(I))and current sensitivity(β_(I))are important parameters for optical TESs,which are generally extracted from the complex *** we present a method to extractα_(I)andβ_(I)based on a two-fluid model and compare the calculated current-voltage curves,pulse response,and theoretical energy resolution with the measured *** method shows qualitative agreement that is suitable for further optimization of optical TESs.

关键词： transition-edge sensor single-photon detector two-fluid model

Validation of an improved two-fluid model with particle rotation for gas-solid fluidized bed

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Particuology 2023年第10期81卷 149-161页

作者： Lian Wang Xihua Chu School of Civil Engineering Wuhan UniversityWuhan430072HubeiChina

Gas-solid fluidized beds are widely applied in chemical and process *** is of significance to establish a reasonable and effective mathematical model to explore the hydrodynamics of gas-particle system for industrial *** a less computationally demanding alternative to the discrete descriptions,two-fluid model considering kinetic theory of granular flow is often adopted to describe the fluidized behaviors of particles,but it cannot characterize the rotation of particles and its influence on the fluidized *** this study,to address the rotation effect of the fluidized particles,a two-fluid model combining the classical fluid and micropolar fluid is established,namely *** the CMTFM,classical fluid is used to describe the motion of gas phase,while micropolar fluid is adopted to describe the motion of particle phase,and the rotation of particles and its influence on the hydrodynamics of the gas-particle system are characterized by the degree of freedom of microrotation and the improved drag force based on micropolar *** the calculation of the gas-solid bubbling fluidized bed,we investigated the influence of the microstructure parameters,particle-particle collision restitution coefficient and inlet velocity,and the results are compared to those from TFM model and *** the analysis,it manifests that pressure drop and expansion height of the fluidized bed under the consideration of the microrotation effect are closer to the experiments,which demonstrates the feasibility and advantage of the classical-micropolar two-fluid model.

关键词： Gas-solid fluidized bed two-fluid model Micropolar fluid Microstructure parameter fluidized behaviors

The global classical solution to a 1D two-fluid model with density-dependent viscosity and vacuum

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Science China Mathematics 2022年第12期65卷 2563-2582页

作者： Senming Chen Changjiang Zhu Department of Mathematics Shantou UniversityShantou 515063China School of Mathematics South China University of TechnologyGuangzhou 510641China

In this paper, we consider the initial-boundary problem for a 1D two-fluid model with densitydependent viscosity and vacuum. The pressure depends on two variables but the viscosity only depends on one of the densities. We prove the global existence and uniqueness of the classical solution in the one-dimensional space with large initial data and vacuum. We use a new Helmholtz free energy function and the material derivative of the velocity field to deal with the general pressure with two variables, without the equivalence condition. We also develop a new argument to handle the general viscosity.

关键词： two-fluid model density-dependent viscosity vacuum global classical solution

A Numerical Study of Characteristic Slow-Transient Behavior of a Compressible 2D Gas-Liquid two-fluid model

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Advances in Applied Mathematics and Mechanics 2009年第2期1卷 166-200页

作者： H.A.Friis S.Evje T.Flåtten International Research Institute of Stavanger(IRIS) Prof.Olav Hanssensvei 15NO-4068 StavangerNorway Department of informatics University of BergenP.O.Box 7800N-5020 BergenNorway SINTEF Energy Research Sem Sælands vei 11NO-7465 TrondheimNorway

The purpose of this paper is to gain some insight into the characteristic behavior of a general compressible two-fluid gas-liquid model in 2D by using numerical *** focus is on mass transport *** few numerical results in higher dimensions can be found in the literature for this two-fluid model,in particular,for cases where mass transport dynamics are *** focus on natural extensions to 2D of known 1D benchmark test cases,like water faucet and gas-liquid separation,previously employed by many researchers for the purpose of testing various numerical *** the numerical investigations,the WIMF discretization method introduced in[SIAM ***.26(2005),1449]is applied,in combination with a standard dimensional splitting *** complicated flow patterns are observed reflecting the balance between acceleration forces,gravity,interfacial forces,and pressure *** essential ingredient in these results is the appearance of single-phase regions in combination with mixture regions(dispersed flow).Solutions are calculated and shown from early times until a steady state is *** refinement studies are included to demonstrate that the obtained solutions are not grid-sensitive.

关键词： two-fluid model hyperbolic numerical scheme pressure-velocity coupling singlephase flow

Study of Argon/Molten Steel two-Phase Flow in Refining of High Clean Steel Using two-fluid model

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Journal of Iron and Steel Research International 2011年第S2期18卷 176-181页

作者： TSUKIHASHI Fumitaka Department of Advanced Materials Science Graduate School of Frontier Science University of Tokyo Kashiwa 277-8561 Japan

RH vacuum degasser is a very important secondary refining device in the production of high quality steels. The flow field of molten steel in RH system plays a significant role in determining productivity of the equipment. The homogeneous model and VOF method were often used to predict the flow field in RH system, but these kinds of models simplified the interaction between gas bubbles and molten steel. In the present work, a numerical model of a whole RH system, including vacuum degasser, immersed legs and ladle,was built based on gas-liquid two-fluid model, and it could be used to analyze the interaction between argon bubbles and molten steel, to understand the effect of the bubble size to the flow field.

关键词： RH vacuum degasser gas-liquid two-phase flow two-fluid model interaction

High-order targeted essentially non-oscillatory scheme for two-fluid plasma model

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Applied Mathematics and Mechanics(English Edition) 2023年第6期44卷 941-960页

作者： Yuhang HOU Ke JIN Yongliang FENG Xiaojing ZHENG School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Institute of Extreme Mechanics Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Space Extreme Detection Xi’an 710071China Research Center for Applied Mechanics Xidian UniversityXi’an 710071China

The weakly ionized plasma flows in aerospace are commonly simulated by the single-fluid model,which cannot describe certain nonequilibrium phenomena by finite collisions of particles,decreasing the fidelity of the *** on an alternative formulation of the targeted essentially non-oscillatory(TENO)scheme,a novel high-order numerical scheme is proposed to simulate the two-fluid plasmas *** numerical flux is constructed by the TENO interpolation of the solution and its derivatives,instead of being reconstructed from the physical *** present scheme is used to solve the two sets of Euler equations coupled with Maxwell's *** numerical methods are verified by several classical plasma *** results show that compared with the original TENO scheme,the present scheme can suppress the non-physical oscillations and reduce the numerical dissipation.

关键词： plasma high-order scheme targeted essentially non-oscillatory(TENO)scheme two-fluid model

Study of Argon/Molten Steel two-Phase Flow in Refining of High Clean Steel Using two-fluid model

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Study of Argon/Molten Steel Two-Phase Flow in Refining of Hi...

two-fluid modelling for cylindrical fluidized beds using kinetic theory for rough spheres

The 2nd International Symposium on Clean Steel(ISCS 2011)

作者： QI Feng-sheng YANG Liu LI Bao-kuan TSUKIHASHI Fumitaka School of Materials and Metallurgy Northeastern University Department of Advanced Materials Science Graduate School of Frontier ScienceUniversity of Tokyo

RH vacuum degasser is a very important secondary refining device in the production of high quality *** flow field of molten steel in RH system plays a significant role in determining productivity of the *** homogeneous model and VOF method were often used to predict the flow field in RH system,but these kinds of models simplified the interaction between gas bubbles and molten *** the present work,a numerical model of a whole RH system,including vacuum degasser,immersed legs and ladle,was built based on gas-liquid two-fluid model,and it could be used to analyze the interaction between argon bubbles and molten steel,to understand the effect of the bubble size to the flow field.

关键词： RH vacuum degasser gas-liquid two-phase flow two-fluid model interaction

来源： cnki会议评论

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Particuology 2020年第3期18卷 25-34页

作者： Lei Yang J.T.Padding J.A.M.Kuipers Helmholtz Institute Erlangen-Nürnberg for Renewable Energy(IEK-11) Fürther Straβe 24890429 NurnbergGermany Department of Process and Energy Delft University of Technology2628CB DelftThe Netherlands Department of Chemical Engineering and Chemistry Eindhoven University of Technology5600MB EindhovenThe Netherlands

Recently,we have extended the kinetic theory of granular flow (KTGF) to include friction between the spherical particles and tested it in rectangular *** this study,the extended KTGF implemented in cylindrical coordinates is used to model the more-commonly employed cylindrical bubbling fluidized *** attention is paid to the anti-symmetric part of the velocity gradient in the solids stress *** verification of the implementation,a comparison of the present model in the limit of zero friction with the original (frictionless) KTGF model was ***,simulations of bubbling fluidized beds of inelastic particles were performed using our extended KTGF and an effective KTGF model for inelastic particles of Jenkins and *** simulation results show good agreement for the time-averaged solids volume fraction distribution and solids circulation ***,our model is validated by predicting the individual bubble behavior in dense bubbling fluidized beds containing different granular materials in a comparison with experimental data from Verma et al.(2014).The extended KTGF leads to an improved agreement with experimental bubble *** to previous work (Yang et al.,2016b,2017c),and by introducing cylindrical coordinates,the current work demonstrates that the extended KTGF improves predictions for the temporal bubble behavior of cylindrical fluidized beds.

关键词： fluidization Frictional collision Rough particles Cylindrical bed hydrodynamics two-fluid model

two-fluid modeling of Geldart A particles in gas-fluidized beds

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Particuology 2008年第6期6卷 540-548页

作者： M.A. van der Hoef J.A.M. Kuipers Faculty of Science & Technology University of Twente

We have investigated the effect of cohesion and drag models on the bed hydrodynamics of Geldart A particles based on the two-fluid （TF） model. For a high gas velocity U0 = 0.03 m/s, we found a transition from the homogeneous fluidization to bubbling fluidization with an increase of the coefficient C1, which is used to account for the contribution of cohesion to the excess compressibility. Thus cohesion can play a role in the bed expansion of Geldart A particles. Apart from cohesion, we have also investigated the influence of the drag models. When using the Wen and Yu drag correlation with an exponent n = 4.65, we find an under-prediction of the bed expansion at low gas velocities （U0 = 0.009 m/s）. When using a larger exponent （n = 9.6）, as reported in experimental studies of gas-fluidization, a much better agreement with the experimental bed expansion is obtained. These findings suggest that at low gas velocity, a scale-down of the commonly used drag model is required. On the other hand, a scale-up of the commonly used drag model is necessary at high gas velocity （U0 = 0.2 and 0.06 m/s）. We therefore conclude that scaling the drag force represent only an ad hoc way of repairing the deficiencies of the TF model, and that a far more detailed study is required into the origin of the failure of the TF model for simulating fluidized beds of fine powders.

关键词： Gas-fluidized bed Geldart A particles two-fluid model Cohesive force Drag correlation