Article
Mechanics
Yiming Qi, Tao Chen, Lian-Ping Wang, Zhaoli Guo, Shiyi Chen
Summary: In this paper, an efficient mesoscopic approach is developed to simulate three-dimensional compressible turbulence. By redefining the distribution and using discrete particle velocity models, the simulation results are in good agreement with existing literature. Additionally, the terms in the transport equation of turbulent kinetic energy are analyzed in detail.
Article
Physics, Condensed Matter
Rodrigo C. Coelho, Luis A. R. G. Cordeiro, Rodrigo B. Gazola, Paulo I. C. Teixeira
Summary: This study simulated the motion of a two-dimensional liquid bridge between two flat solid substrates with specific wettabilities using a multicomponent pseudopotential lattice Boltzmann method. The study investigated the drag force exerted by the moving bridge, the deformation of the bridge, and the conditions under which the bridge would break.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Mechanics
Tao Chen, Xin Wen, Lian-Ping Wang, Zhaoli Guo, Jianchun Wang, Shiyi Chen, Dauren B. Zhakebayev
Summary: In this paper, a Boltzmann-equation-based mesoscopic model is implemented to simulate 3D forced compressible isotropic turbulence. The simulation results validate the reliability and potential of the DUGKS method for simulating compressible turbulence.
Article
Mechanics
Ao Xu, Ben-Rui Xu, Li-Sheng Jiang, Heng-Dong Xi
Summary: In this study, we numerically investigate the production and transport of vorticity in two-dimensional Rayleigh-Benard convection. The flow structure and temperature distribution are found to be greatly influenced by the interaction of multiple vortices. Besides vorticity produced by wall shear stress, buoyancy also plays a significant role in generating vorticity in the bulk region. The produced vorticity is then transported through advection and diffusion. The visualization of buoyancy-produced vorticity contours allows for the observation of main and corner vortices. The correlation between the spatial distribution of vorticity flux along the wall and the Nusselt number suggests a direct relationship between the amount of vorticity entering the flow and the amount of thermal energy entering the flow.
Article
Physics, Fluids & Plasmas
Zhaoli Guo, Lian-Ping Wang, Yiming Qi
Summary: In this paper, a discrete unified gas kinetic scheme (DUGKS) is proposed for continuum compressible gas flows based on the total energy kinetic model. The DUGKS can be viewed as a special finite-volume lattice Boltzmann method for the compressible Navier-Stokes equations in the double distribution function formulation. The computational efficiency of the proposed DUGKS is much improved compared to previous versions.
Article
Physics, Fluids & Plasmas
L. M. Yang, C. Shu, Z. Chen, Y. Y. Liu, J. Wu, X. Shen
Summary: A high-order gas kinetic flux solver (GKFS) is developed for 2D compressible flows, which evaluates numerical fluxes based on the local asymptotic solution to the Boltzmann equation. It achieves high-order accuracy through a simplified local asymptotic solution and outperforms the second-order counterpart in numerical examples, demonstrating its accuracy and capability.
Article
Computer Science, Software Engineering
Wei Li, Yihui Ma, Xiaopei Liu, Mathieu Desbrun
Summary: This paper proposes a new solver for coupling the incompressible Navier-Stokes equations with a conservative phase-field equation to simulate multiphase flows. The resulting solver shows efficiency, versatility, and reliability in dealing with large density ratios, high Reynolds numbers, and complex solid boundaries.
ACM TRANSACTIONS ON GRAPHICS
(2022)
Article
Chemistry, Multidisciplinary
Tong Wu, Kang Liu, Shuhai Liu, Xiaolong Feng, Xuefeng Wang, Longfei Wang, Yong Qin, Zhong Lin Wang
Summary: This study demonstrates the flexocatalysis effect in 2D centrosymmetric semiconductors for the first time, expanding polarization-based mechanocatalysis to these materials. By inducing flexoelectric polarization in MnO2 nanosheets, organic pollutants can be effectively degraded within 5 minutes, comparable to the performance of piezocatalysis, with excellent stability and reproducibility. The factors related to flexocatalysis, such as material morphology, adsorption, mechanical vibration intensity, and temperature, are explored to gain deep insights into mechanocatalysis.
ADVANCED MATERIALS
(2023)
Article
Physics, Fluids & Plasmas
Yikun Wei, Yumeng Li, Zhengdao Wang, Hui Yang, Zuchao Zhu, Yuehong Qian, Kai H. Luo
Summary: The effect of rotation on small-scale characteristics and scaling laws in the mixing zone of the three-dimensional turbulent Rayleigh-Taylor instability was investigated. Rotation suppresses the growth of mixing layer width and energy spectra, as well as narrows the width of the inertial subrange.
Article
Multidisciplinary Sciences
Xiaoyingjie Huang, Jiabao Chen, Jun Zhang, Long Wang, Yan Wang
Summary: An adaptive mesh refinement-rotated lattice Boltzmann flux solver (AMR-RLBFS) was developed to simulate compressible flows with complex shock structures. The method uses the RLBFS to solve the flow field by adaptively reconstructing the fluxes at each cell interface, and introduces a block-structured adaptive mesh refinement (AMR) technique to locally improve the resolution of shock structures. Numerical tests demonstrate the effectiveness and accuracy of the proposed method, which performs well in capturing complex shock structures and improves computational efficiency compared to uniform grids. This research highlights the importance of AMR-RLBFS in studying a wide range of compressible flows.
Article
Mechanics
Lei Xu, Wu Zhang, Yuhui Chen, Rongliang Chen
Summary: This paper proposes a parallel discrete unified gas kinetic scheme (DUGKS) for simulating inviscid high-speed compressible flows on unstructured grids. The method calculates the gradients of distribution functions using a least-square method and employs a graph-based partitioning method for load balancing and minimizing communication among processors. The numerical results validate the effectiveness and scalability of the proposed method.
Article
Mechanics
Luis A. Mora, Yann Le Gorrec, Denis Matignon, Hector Ramirez, Juan Yuz
Summary: This manuscript presents a general formulation of 3-dimensional compressible fluids based on the port-Hamiltonian framework, discussing both isentropic and non-isentropic assumptions and describing the energy flux between different domains. For isentropic fluids, energy dissipation due to viscous friction converting kinetic energy into heat is considered, leading to a dissipative port-Hamiltonian formulation. For non-isentropic fluids, a pseudo port-Hamiltonian formulation is proposed to describe energy fluxes involving irreversible processes such as heat flux, chemical reactions, diffusion of matter, and viscous friction.
Article
Engineering, Marine
B. Afra, S. Karimnejad, A. Amiri Delouei, A. Tarokh
Summary: In this study, the combination of Lattice Spring Method (LSM) and Immersed Boundary-Lattice Boltzmann Method (IB-LBM) is employed to investigate fluid-elastic body interaction problems under unsteady conditions. The method eliminates the need for arbitrary spring parameters to determine the deformation of the flexible body. Numerical simulations are conducted to examine the effects of various variables on the lift and drag coefficients of tandem cylinders. The results show that the fluctuations of the lift coefficient are reduced when the filament's capillary number is at its maximum value and the filament's clamped edge is located in the middle of the cylinders. Additionally, increasing the filament's length results in a significant reduction in the drag coefficient on the downstream cylinder.
Article
Mechanics
Xin Wen, Lian-Ping Wang, Zhaoli Guo
Summary: The study applies DUGKS to simulate three-dimensional compressible natural convection and introduces a highly efficient lattice velocity model, D3Q77A9, with a ninth-order accuracy Gauss-Hermite quadrature. Error analysis emphasizes the importance of combining quadrature precision with the proper order of Hermite expansion.
Article
Mathematics, Applied
Xiang Zhao, Liming Yang, Chang Shu
Summary: This paper proposes a novel implicit lattice Boltzmann flux solver for simulating flows around complex geometries. The solver combines dual time-stepping technique and sub-iteration to efficiently simulate unsteady flows. Various simulations were conducted to demonstrate the accuracy and efficiency of the proposed solver, and it was also used to simulate the flow over complex aircraft models in practical engineering applications.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2022)