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Frontiers of Physics

ISSN 2095-0462

ISSN 2095-0470(Online)

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Front. Phys.    2024, Vol. 19 Issue (4) : 42500    https://doi.org/10.1007/s11467-023-1353-8
Advances in the kinetics of heat and mass transfer in near-continuous complex flows
Aiguo Xu1,2,3(), Dejia Zhang1,4,5, Yanbiao Gan6
1. National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, P. O. Box 8009-26, Beijing 100088, China
2. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
3. HEDPS, Center for Applied Physics and Technology, and College of Engineering, Peking University, Beijing 100871, China
4. State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083, China
5. National Key Laboratory of Shock Wave and Detonation Physics, Mianyang 621999, China
6. Hebei Key Laboratory of Trans-Media Aerial Underwater Vehicle, School of Liberal Arts and Sciences, North China Institute of Aerospace Engineering, Langfang 065000, China
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Abstract

The study of macro continuous flow has a long history. Simultaneously, the exploration of heat and mass transfer in small systems with a particle number of several hundred or less has gained significant interest in the fields of statistical physics and nonlinear science. However, due to absence of suitable methods, the understanding of mesoscale behavior situated between the aforementioned two scenarios, which challenges the physical function of traditional continuous fluid theory and exceeds the simulation capability of microscopic molecular dynamics method, remains considerably deficient. This greatly restricts the evaluation of effects of mesoscale behavior and impedes the development of corresponding regulation techniques. To access the mesoscale behaviors, there are two ways: from large to small and from small to large. Given the necessity to interface with the prevailing macroscopic continuous modeling currently used in the mechanical engineering community, our study of mesoscale behavior begins from the side closer to the macroscopic continuum, that is from large to small. Focusing on some fundamental challenges encountered in modeling and analysis of near-continuous flows, we review the research progress of discrete Boltzmann method (DBM). The ideas and schemes of DBM in coarse-grained modeling and complex physical field analysis are introduced. The relationships, particularly the differences, between DBM and traditional fluid modeling as well as other kinetic methods are discussed. After verification and validation of the method, some applied researches including the development of various physical functions associated with discrete and non-equilibrium effects are illustrated. Future directions of DBM related studies are indicated.

Keywords near-continuous flow      non-equilibrium      kinetics      discrete Boltzmann method      complex physical field analysis     
Corresponding Author(s): Aiguo Xu   
Issue Date: 29 February 2024
 Cite this article:   
Aiguo Xu,Dejia Zhang,Yanbiao Gan. Advances in the kinetics of heat and mass transfer in near-continuous complex flows[J]. Front. Phys. , 2024, 19(4): 42500.
 URL:  
https://academic.hep.com.cn/fop/EN/10.1007/s11467-023-1353-8
https://academic.hep.com.cn/fop/EN/Y2024/V19/I4/42500
Fig.1  (a) Sketch of the formation mechanism of KHI. (b) Sketch of the formation mechanism of RTI.
Fig.2  The mesoscale dilemma between macroscopic continuous and microscopic particle descriptions.
Fig.3  The three main steps of complex flow simulation research.
Fig.4  Schematic of phase space description method.
Fig.5  Schematic of several commonly used two-dimensional discrete velocity sets.
Fig.6  Schematic diagram of the application scopes of the Boltzmann equation, the original BGK model, and the BGK-like model in kinetic methods.
Fig.7  Phase space description methods: from non-conserved moments of ff (0) to any set of system characteristics.
Fig.8  Schematic for application ranges of several physical models.
Year Schemes for detecting and describing discrete/TNE behavior and effects
Before 2012 There was no significant difference in physical function between the two types of LBMs.
2012 Proposed to use non-conserved moments of ff( 0) to detect and describe discrete/TNE states and effects, which is the starting point of current DBM method [73].
2015 Proposed to use the non-conserved moments of ff( 0) as bases to open phase space, and use the distance from a state point to the origin to define the TNE strength of one perspective. This is the starting point of the phase space description method in DBM [74].
2018 Proposed to use the distance between two points in the phase space to describe the difference between two discrete/TNE states, and use the mean distance between two points in a given time interval to describe the difference of two kinetic processes [75].
2021 Extended the phase space method to describe any set of system features [76].
2022 Proposed the concept of non-equilibrium strength vector, each of whose components is one TNE strength of a perspective, to multi-perspective cross-locate the non-equilibrium strength of complex flow [61, 77].
Tab.1  Milestones in the development of DBM.
Fig.9  Kinetic moments that should keep value in various levels of DBM.
Fig.10  Flowchart for DBM simulation.
Fig.11  Two dimensions of the perspective of complex flow behavior research.
Fig.12  Schematic of discretization of particle velocity space. The velocity discretization in x direction is taken as example.
Fig.13  Comparison of DBM simulation and DSMC simulation of a shock structure. Reproduced with permission from Ref. [77].
Fig.14  Schematic of velocity slip and temperature jump in Knudsen layer.
Fig.15  Comparison between DBM simulation results and analytical solutions: slip velocity. Reproduced with permission from Ref. [92].
Fig.16  Comparison between DBM simulation results and analytical solutions: velocity difference profile. Reproduced from Ref. [94] with permission.
Fig.17  Comparison between DBM simulation results and analytical solutions: temperature difference profile. Reproduced with permission from Ref. [94].
Fig.18  The results of Couette flow at steady state: (a) velocity profiles, the symbols are DSMC data and the lines denote DBM results; (b) viscous shear stress profiles, the symbols denote DSMC data, the dashed line represents the Lattice ES-BGK results, and the solid line represents the DBM results. Reproduced with permission from Ref. [93].
Fig.19  Pressure-driven flow. (a) Schematic, and (b) DBM simulation results of velocity contour under different Kn numbers. Reproduced with permission from Ref. [94].
Fig.20  (a) Profiles of pressure p(x) along the central line under different Kn numbers. (b) Profiles of ux along the y direction under different Kn numbers. Reproduced with permission from Ref. [94].
Fig.21  Inverse reduced mass flow rate under various Knudsen numbers, in which including the results of DBM simulation, NS simulation and experiment. Reproduced with permission from Ref. [94].
Fig.22  Simulation results of non-equilibrium cavity flow in steady state. (a) Temperature contour. (b) Heat flow streamline. (c) Horizontal velocity distribution on the vertical centerline. (d) Vertical velocity distribution on the vertical centerline. Reproduced with permission from Ref. [93].
Fig.23  Comparison of Δ 2,xx profile between DBM simulation results and analytical results. The three figures represent the cases of weak, medium, and strong TNE strength, respectively. The two symbols indicate the results of first-order and second-order DBM, respectively, with lines representing the analytical results at two TNE levels. Reproduced with permission from Ref. [77].
Fig.24  The DBM simulation results from different orders of DBM. Reproduced with permission from Ref. [77].
Fig.25  Comparison of Δ 2,xx profile between DBM simulation results and analytical results. Each row of the pictures show corresponds to cases with weak, moderate, and strong TNE strength, and each column corresponds to the results of D2V13, D2V15, and D2V30, respectively. In the figures, the circles represent results from DBM at various levels, the green lines and green points are results calculated from the first theoretical analysis, and red lines denote results obtained from the second theoretical analysis. Reproduced with permission from Ref. [65].
Fig.26  Evolution of spike amplitude. The red points in the picture are experimental results from Ref. [102], and blue line represent DBM results. Reproduced with permission from Ref. [100].
Fig.27  Snapshots of schlieren images of the interaction between a shock wave and a heavy-cylindrical bubble. The odd rows represent experimental results from Ref. [34] with permission, and the even rows are DBM simulation results. Numbers in the picture represent the time in μs. Reproduced with permission from Ref. [103].
Fig.28  Evolution curves of the characteristic scale of shock−bubble interaction. The lines indicate DBM simulation results and the symbols are experimental results extracted from Ref. [34]. Reproduced with permission from Ref. [103].
Fig.29  Comparison between DBM results and NS results of pressure profile at the line y=0.625π in simulation of Orszag−Tang magnetic turbulence. Reproduced with permission from Ref. [43].
Fig.30  (a) Profiles of the dimensionless mass flow rate with various rarefaction parameters under three different values of TMAC for the one-dimensional pressure driven flow through a microchannel. (b) Profiles of the dimensionless mass flow rate with rarefaction parameters for three different aspect ratios in the context of the two-dimensional pressure-driven flow through a microchannel. Reproduced with permission from Ref. [64].
Fig.31  Comparison of three entropy production rates in fluid systems of detonation problems with chemical reactions. Reproduced with permission from Ref. [90].
Fig.32  Contours of the two typical TNE quantities |Δ 2σ| and | Δ3 ,1 σ| at three different moments. Reproduced with permission from Ref. [110].
Fig.33  Profiles of average TNE strength along the y direction. Reproduced with permission from Ref. [110].
Fig.34  Evolution curves of the quantity of global TNE strength. Reproduced with permission from Ref. [110].
Fig.35  Evolution curves of boundary length L and non-equilibrium strength D in non-isothermal phase separation process. Reproduced with permission from Ref. [111].
Fig.36  Evolution curves of several characteristic quantities in the phase separation process. Reproduced with permission from Ref. [112].
Fig.37  Evolution curves of average coalescence velocity u ¯ and Δ ¯2,xx. Reproduced with permission from Ref. [113].
Fig.38  Evolution curves of the average strength D ¯ , average coalescence velocity a ¯, the slope of boundary length dL/dt, and ( u:u)0.5 ¯. Reproduced with permission from Ref. [113].
Fig.39  Evolution curves of two TNE quantities (D ¯2 and D ¯3) during the droplet collisions, where (a) represents the two droplets are fused together after the head-on collision, (b) indicates the two droplets are separated after collision. Reproduced with permission from Ref. [36].
Fig.40  Evolution curves of change rate of entropy production rate dS ˙NOMF/ dt, change rate of boundary length dL/dt, and bubble velocity Vbubble. Reproduced with permission from Ref. [115].
Fig.41  Evolution curves of boundary length L and strength of NOEF D3,1 in coupled RT-KHI system. These two figures correspond to the cases with different initial shear velocity. Reproduced with permission from Ref. [118].
Fig.42  Profiles of Δ 2 and Δ 4,2 of plasma shock wave with different Ma numbers. Reproduced with permission from Ref. [119].
Fig.43  TNE effects of Orszag−Tang vortex problem. (a) Contour of total TNE strength at t=3. (b) Evolution of four kinds of entropy production rates with time. Reproduced with permission from Ref. [43].
Fig.44  Evolution of global average TNE effects with different initial applied magnetic fields from t=0 to 500. Reproduced with permission from Ref. [43].
Fig.45  Evolution of entropy production rates from t=0 to 500 with magnetic fields ranging from 0.01 to 0.05. Reproduced with permission from Ref. [43].
Fig.46  Evolution of entropy production rates from t=0 to 500 with magnetic fields ranging from 0.10 to 0.30. Reproduced with permission from Ref. [43].
Fig.47  The sketch of the two-dimensional contours of actual distribution function in velocity space (v r,vθ) at rarefaction front, material interface, and shock front, respectively. Reproduced with permission from Ref. [121].
Fig.48  The three-dimensional contour graph of the actual distribution function in velocity space (v r,vθ) at rarefaction front, material interfaces, and shock fronts, respectively. Reproduced with permission from Ref. [121].
Fig.49  Profiles of four types of TNE quantities. Each column of the figure represent different TNE quantities, and each row indicate the case with various positions. Reproduced with permission from Ref. [121].
Fig.50  Contours of various TNE quantities at a typical moment during the RTI evolution. Reproduced with permission from Ref. [125].
Fig.51  Evolution curve of interface amplitude obtained from two kinds of tracking techniques. Reproduced with permission from Ref. [126].
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