Article
Computer Science, Interdisciplinary Applications
Shaolei Gai, Zhengbiao Peng, Behdad Moghtaderi, Jianglong Yu, Elham Doroodchi
Summary: In this study, the conventional lattice Boltzmann method (LBM) was extended to investigate ice nucleation induced by the collapse of a cavitation bubble. The developed model accurately predicted the water vapour-liquid coexistence curve and examined two practical application scenarios of ice nucleation. The results showed that different system parameters had varying effects on the maximum collapse pressure and ice nucleation in different scenarios.
COMPUTERS & FLUIDS
(2022)
Article
Computer Science, Interdisciplinary Applications
Shaolei Gai, Zhengbiao Peng, Behdad Moghtaderi, Jianglong Yu, Elham Doroodchi
Summary: This study extended the conventional lattice Boltzmann method to investigate ice nucleation induced by the collapse of a cavitation bubble. It found that different system parameters can affect the maximum collapse pressure and ice nucleation in different application scenarios.
COMPUTERS & FLUIDS
(2022)
Article
Thermodynamics
Xiang Song, Jianmin Zhang, Haonan Peng, Shiliang Zhou
Summary: A modified double distribution function thermal lattice Boltzmann method is used to study the effect of surface tension on the interaction between equal-sized and unequal-sized bubbles. The study considers the entire evolution process of laser or spark-produced bubbles, while taking into account the temperature and flow fields. A modified Rayleigh-Plesset equation is employed to predict the evolution of bubble radius, and the effects of surface tension on bubble coalescence are analyzed.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Xiaolong He, Haonan Peng, Jianmin Zhang, Yang Liu
Summary: Investigated the hydrodynamics and thermodynamics of attached wall vapor cavitation bubble collapse under different wall wettability using an improved double distribution function thermal pseudo-potential model. Found that wettability significantly affects bubble morphology and captured the peaks on the temperature distribution curves caused by phase transition and high-pressure regions.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Yu Yang, Minglei Shan, Nana Su, Xuefen Kan, Yanqin Shangguan, Qingbang Han
Summary: The thermal lattice Boltzmann method is used to simulate cavitation bubble collapse in heating or cooling systems. The results are consistent with Laplace's law and temperature solutions derived from the Rayleigh-Plesset equation. The effects of wall temperature on a collapsing bubble are studied, and the influence mechanism of the micro-jet and the cavitation bubble itself on solid-wall heat transfer, as well as the thermodynamic behavior characteristics of the cavitation bubble collapse near the wall, are obtained. The study also introduces a dimensionless temperature parameter to analyze the heat transfer intensity of the model.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Computer Science, Interdisciplinary Applications
Haonan Peng, Jianmin Zhang, Xiaolong He, Yurong Wang
Summary: The paper explores the collapse process of cavitation bubbles near a rigid boundary using the double distribution function thermal lattice Boltzmann method. The simulation results show that this method is reliable for studying thermal cavitation bubble dynamics.
COMPUTERS & FLUIDS
(2021)
Article
Computer Science, Interdisciplinary Applications
Xiaolong He, Haonan Peng, Jianmin Zhang, Hao Yuan
Summary: This paper presents a double-distribution-function thermal lattice Boltzmann method for studying the thermodynamics of multiple-bubble interactions, and proposes a new two-dimensional method for cavitation bubble inception without gas nuclei initialization. The approach is validated by simulating the evolution of a laser-produced bubble, accurately reproducing weak and strong interactions among bubbles of equal size, as well as interactions among bubbles of different sizes.
COMPUTERS & FLUIDS
(2023)
Article
Mathematics, Applied
Xiaolong He, Xiang Song, Haonan Peng, Hao Yuan
Summary: A two-dimensional double-distribution-function thermal pseudo-potential lattice Boltzmann model is used to investigate the inception and evolution processes of cavitation bubbles. The interactions between equal-sized and unequal-sized bubbles are studied, and a modified Rayleigh-Plesset equation is proposed. The effects of weak and strong interactions on the collapse temperature and the collapse direction of the bubbles are analyzed.
DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES S
(2023)
Article
Engineering, Marine
Yang Liu, Yong Peng
Summary: Through verification and application, this improved LBM model can accurately predict the collapse of cavitation bubbles, including heat transfer, and for the first time, includes the interaction between density and temperature fields in the LBM model.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Acoustics
Hossein Haghi, Michael C. Kolios
Summary: This study examines the effect of bubble-bubble interactions on the resonance frequency of MB suspensions. It is found that primary delays cause spreading the resonance frequency of identical MBs within a range, where the closest MB to the acoustic source exhibits the lowest resonance frequency and the furthest MB resonates at the highest frequency. The inclusion of secondary delays also significantly affects the resonance frequency, resulting in an increase when the MBs are situated close to each other.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Mechanics
Fabian Reuter, Qingyun Zeng, Claus-Dieter Ohl
Summary: This study measures the prolongation factor k of the collapse time for water bubbles near a solid boundary and compares the experimental findings to numerical simulations. The influence of viscosity on k in the near-wall regime is also studied.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Qingyun Zeng, Hongjie An, Claus-Dieter Ohl
Summary: The study systematically examines the cavitation-induced wall shear stress on rigid boundaries as a function of liquid viscosity and stand-off distance using axisymmetric VoF simulations. The simulations accurately predict the dynamics of bubbles and the liquid film thickness before collapse. The spatial and temporal wall shear stress is analyzed in detail, showing inward stress from shrinking bubbles and outward stress from expanding bubbles and jet spreading.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Youssef Saade, Maziyar Jalaal, Andrea Prosperetti, Detlef Lohse
Summary: The study reveals that the formation mechanism of the crown is a combination of pressure distortion and induced flow focusing on the curved interface, as well as flow reversal caused by the second expansion of the toroidal bubble. A parametric study with control parameters such as Weber number, Reynolds number, pressure ratio, and dimensionless bubble distance to the free surface shows their effects on both the central jet and the crown formation. High Weber numbers lead to the formation of weaker 'secondary crowns', highly correlated with the third oscillation cycle of the bubble.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Jingzhu Wang, Hongchen Li, Wenlu Guo, Zhan Wang, Tezhuan Du, Yiwei Wang, Akihisa Abe, Chenguang Huang
Summary: This study investigates the interfacial instability of water droplets through a combination of experimental, numerical, and analytical methods. An analytical model is developed considering the Rayleigh-Taylor instability and bubble oscillation to describe three distinct phenomena. Two dimensionless parameters are used to determine the boundaries between different regimes.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Rui Han, A-Man Zhang, Sichao Tan, Shuai Li
Summary: The study investigates the nonlinear interaction between a cavitation bubble and the interface of two immiscible fluids. Two mechanisms contributing to fluid mixing are identified, including a high-speed liquid jet generated from the collapsing bubble and the pinch-off of an interface jet carrying droplets into the oil bulk.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mathematics, Applied
Yong Wang, Sha Liu, Congshan Zhuo, Chengwen Zhong
Summary: This paper investigates the nonlinear squeeze-film damping involving rarefied gas effect in MEMS, introducing the kinetic method DUGKS and two solving methods to study the dynamics of structures under forced and free oscillations. Numerical results and discussions on the nonlinear SFD phenomenon and the influence of oscillation frequency on damping force or torque are presented.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2022)
Article
Mechanics
Zeren Yang, Sha Liu, Congshan Zhuo, Chengwen Zhong
Summary: The novel MDUGKS is proposed for modeling multiphase flows with large density ratios, overcoming stability issues encountered by standard DUGKS on multilevel meshes. Numerical solutions are in good agreement with theoretical predictions, demonstrating high efficiency and accuracy in steady and unsteady cases.
Article
Mechanics
Miao Zhang, Haibao Hu, Peng Du, Xiaopeng Chen, Zhuoyue Li, Chao Wang, Lu Cheng, Zijian Tang
Summary: A new hydrodynamic artificial intelligence detection method is proposed to accurately detect internal solitary waves (ISWs) by the underwater vehicle. The method utilizes deep convolutional neural networks to predict the relative position between the underwater vehicle and ISW, as well as the flow field around the vehicle. The study demonstrates high prediction accuracy and the potential to enhance navigation safety of underwater vehicles.
Article
Engineering, Multidisciplinary
Yong Wang, Sha Liu, Congshan Zhuo, Chengwen Zhong
Summary: In this paper, an arbitrary Lagrangian-Eulerian (ALE) framework is introduced into the conserved discrete unified gas-kinetic scheme (CDUGKS) to solve transonic continuum and rarefied gas flows with moving boundary. The proposed ALE-CDUGKS updates both the distribution function and the conservative flow variables, and it shows high computational efficiency for flows in both continuum and rarefied regimes. The method incorporates the potential energy double-distribution-functions framework and the circle equilibrium distribution function model for continuum flows, and introduces unstructured velocity-space mesh technique for rarefied flows to reduce computational load. The capability of the proposed ALE-CDUGKS for solving compressible moving boundary problems with rarefied gas effect is demonstrated through simulations of various test cases.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Computer Science, Interdisciplinary Applications
Dongxin Pan, Rui Zhang, Congshan Zhuo, Sha Liu, Chengwen Zhong
Summary: This study presents a multi-scale implicit multi-degree-of-freedom (MDOF) kinetic model that includes translational, rotational, and vibrational effects of molecules. The energy exchange among these degrees of freedom is demonstrated through three coupled relaxation processes. A sequence of objective distribution functions is constructed using an orthogonal polynomial system to incorporate heat transfer and viscosity properties. The numerical tests validate the accuracy and efficiency of the model, showing significant improvements in computational efficiency compared to the explicit method. This method provides insights into energy exchange during molecular inelastic collisions and enables fast simulation of multi-scale flows.(c) 2022 Elsevier Inc. All rights reserved.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Mathematics, Applied
Rui Zhang, Sha Liu, Chengwen Zhong, Congshan Zhuo
Summary: This paper proposes a BGK-type kinetic model for diatomic gases to describe the high-temperature thermodynamic non-equilibrium effect. A unified gas-kinetic scheme (UGKS) with simplified multi-scale numerical flux is proposed for thermodynamic non-equilibrium flows. The present UGKS results agree well with the benchmark data of DSMC and other validated methods.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Mechanics
Sen Zou, Lin Bi, Chengwen Zhong, Xianxu Yuan, Zhigong Tang
Summary: A linear stability equation suitable for rarefied flows is derived based on the Bhatnagar-Gross-Krook (BGK) equation using stability analysis method. Modal and non-modal analysis are performed using the global method and singular value decomposition method. The results are validated against Navier-Stokes (NS) equations. It is found that the NS-LSEs begin to fail when the Knudsen number (Kn) exceeds 0.01. The rarefaction effect plays a stabilizing role in transient growth.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Dongxin Pan, Congshan Zhuo, Sha Liu, Chengwen Zhong
Summary: A multi-degree-of-freedom (MDOF) kinetic model is developed to simulate three-dimensional nonequilibrium flows by indicating a multi-scale molecular collision mechanism with translational, rotational, and vibrational degrees of freedom. This model accurately explains the energy exchange of polyatomic molecules in high-temperature gas and proves to be an effective tool for nonequilibrium aerodynamic research.
COMPUTERS & FLUIDS
(2023)
Article
Mechanics
Qingdian Zhang, Congshan Zhuo, Junlei Mu, Chengwen Zhong, Sha Liu
Summary: In this study, the Rykov model is introduced to broaden the application scope of MDVM, enabling it to simulate multi-scale, strongly non-equilibrium, diatomic molecular gas flow, with certain efficiency improvements compared to the diatomic UGKS.
Article
Mechanics
Guang Zhao, Chengwen Zhong, Sha Liu, Jianfeng Chen, Congshan Zhuo
Summary: The Reaction Control System (RCS) is a force control system used to adjust a craft's attitude or orbit through the reaction force created by jet flow. It is frequently utilized in managing near-space vehicles due to its fast response time and effective control efficiency. A numerical approach called the Conserved Discrete Unified Gas Kinetic Scheme, which applies the Boltzmann equation unconstrained by the continuum hypothesis, is employed to model the interaction flow field between hypersonic free stream and lateral jet in the rarefied atmosphere.
Article
Mechanics
Peiyuan Geng, Sha Liu, Sirui Yang, Junzhe Cao, Congshan Zhuo, Chengwen Zhong
Summary: Multi-scale phenomena are prevalent and significant in various disciplines. This paper aims to overcome the restriction of numerical methods based on model equations by replacing the collision operators with a simple direct relaxation (DR) process. The DR strategy allows for the establishment of a numerical method without constructing collision operators, and it also has the flexibility to recover various models. Additionally, a generalized numerical boundary condition is considered to accommodate subsonic, supersonic, and hypersonic flows at the inlet/outlet boundaries.
Article
Mechanics
Guang Zhao, Chengwen Zhong, Sha Liu, Yong Wang, Congshan Zhuo
Summary: This paper presents a gas-kinetic scheme (GKS) based on unstructured mesh, with a kinetic boundary condition. The boundary conditions are constructed using the gas distribution function, similar to the diffuse-scattering rule used in other kinetic schemes. The use of unstructured mesh expands the adaptability of GKS to simulate flows with complex geometries. The kinetic boundary condition improves the calculation results in near-continuum flows and can be used as a reference for construction and optimization of GKS-based multi-scale hybrid algorithms.
INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS
(2022)
Article
Engineering, Mechanical
Zeren Yang, Sha Liu, Congshan Zhuo, Chengwen Zhong
Summary: In this paper, a pseudopotential-based discrete unified gas-kinetic scheme (DUGKS) is developed to simulate multiphase fluid flow by incorporating intermolecular interaction effects. The isotropy-preserving property of the pseudopotential-based DUGKS is validated through spinodal decomposition and predicting coexistence densities. By directly considering intermolecular interactions, this method offers a mesoscopic perspective for understanding multiphase behaviors.
ADVANCES IN AERODYNAMICS
(2022)
Article
Engineering, Mechanical
Ruqian Guo, Xiaopeng Chen, Zhenhua Wan, Haibao Hu, Shuai Cui
Summary: This study numerically investigates the effects of filled porous media on the flow over an open cavity using the lattice Boltzmann method in a two-dimensional space. The results show that the outcomes of the porous patch depend on its location and the original flow mode. For shear layer flow, the porous patch either dampens the vortical flow or suppresses the generation of secondary vortex sheet. This destabilizes the flow and reduces the radiated sound if the patch is on the trailing edge, and increases it if the patch is on the floor. In the case of wake mode flow, the presence of the porous patch leads to a transition from wake mode to shear layer mode, making the wake mode flow unsustainable. Furthermore, the porous patch on the trailing edge slightly weakens the sound through dissipation. The study suggests that careful placement of porous media in the flow field can decrease the radiated sound level.
ACTA MECHANICA SINICA
(2022)
Article
Computer Science, Artificial Intelligence
Sina Dang, Hongjun Xue, Xiaoyan Zhang, Chengwen Zhong, Caiyong Tao
Summary: In this study, a three-dimensional human heat transfer model has been improved based on anthropometric data of Chinese pilots, and the simulated temperature distribution was verified through experimental studies.
NEURAL COMPUTING & APPLICATIONS
(2022)
Article
Mathematics, Applied
Junfeng Cao, Ke Chen, Huan Han
Summary: This paper proposes a two-stage image segmentation model based on structure tensor and fractional-order regularization. In the first stage, fractional-order regularization is used to approximate the Hausdorff measure of the MS model. The solution is found using the ADI scheme. In the second stage, thresholding is used for target segmentation. The proposed model demonstrates superior performance compared to state-of-the-art methods.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
Article
Mathematics, Applied
Dylan J. Oliver, Ian W. Turner, Elliot J. Carr
Summary: This paper discusses a projection-based framework for numerical computation of advection-diffusion-reaction (ADR) equations in heterogeneous media with multiple layers or complex geometric structures. By obtaining approximate solutions on a coarse grid and reconstructing solutions on a fine grid, the computational cost is significantly reduced while accurately approximating complex solutions.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
Article
Mathematics, Applied
Nathan V. Roberts, Sean T. Miller, Stephen D. Bond, Eric C. Cyr
Summary: In this study, the time-marching discontinuous Petrov-Galerkin (DPG) method is applied to the Vlasov equation for the first time, using backward Euler for a Vlasov-Poisson discretization. Adaptive mesh refinement is demonstrated on two problems: the two-stream instability problem and a cold diode problem.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
Article
Mathematics, Applied
Yizhi Sun, Zhilin Sun
Summary: This work investigates the convexity of a specific class of positive definite probability measures and demonstrates the preservation of convexity under multiplication and intertwining product. The study reveals that any integrable function on an interval with a polynomial expansion of fast absolute convergence can be decomposed into a pair of positive convex interval probabilities, simplifying the study of interval distributions and discontinuous probabilistic Galerkin schemes.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
Article
Mathematics, Applied
Bhagwan Singh, Komal Jangid, Santwana Mukhopadhyay
Summary: This paper examines the prediction of bending characteristics of nanoscale materials using the Moore-Gibson-Thompson thermoelasticity theory in conjunction with the nonlocal strain gradient theory. The study finds that the stiffness of the materials can be affected by nonlocal and length-scale parameters, and the aspect ratios of the beam structure play a significant role in bending simulations.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
Article
Mathematics, Applied
Guoliang Wang, Bo Zheng, Yueqiang Shang
Summary: This paper presents and analyzes a parallel finite element post-processing algorithm for the simulation of Stokes equations with a nonlinear damping term, which integrates the algorithmic advantages of the two-level approach, the partition of unity method, and the post-processing technique. The algorithm generates a global continuous approximate solution using the partition of unity method and improves the smoothness of the solution by adding an extra coarse grid correction step. It has good parallel performance and is validated through theoretical error estimates and numerical test examples.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
Article
Mathematics, Applied
Hao Xu, Zeng-Qi Wang
Summary: Fluid flow control problems are crucial in industrial applications, and solving the optimal control of Navier-Stokes equations is challenging. By using Oseen's approximation and matrix splitting preconditioners, we can efficiently solve the linear systems and improve convergence.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
Article
Mathematics, Applied
Zhengya Yang, Xuejuan Chen, Yanping Chen, Jing Wang
Summary: This paper focuses on the high-order stable numerical solutions of the time-space fractional diffusion equation. The Fourier spectral method is used for spatial discretization and the Spectral Deferred Correction (SDC) method is used for numerical solutions in time. As a result, a high-precision numerical discretization scheme for solving the fractional diffusion equation is obtained, and the convergence and stability of the scheme are proved. Several numerical examples are presented to demonstrate the effectiveness and feasibility of the proposed numerical scheme.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2024)
