Article
Mechanics
Alessandro Ferrari
Summary: New analytical solutions have been obtained for the one-dimensional steady-state compressible viscous adiabatic flow of an ideal gas through a conical nozzle or diffuser. The solutions have been validated through dimensionless representation and fluid dynamics analysis for both subsonic and supersonic flows. The proposed solutions complement existing models and expand the collection of exact solutions in gas dynamics.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Computer Science, Interdisciplinary Applications
L. Santelli, P. Orlandi, R. Verzicco
Summary: This study presents a numerical scheme for simulating three-dimensional incompressible flows in spherical coordinates, which addresses the singularities of Navier-Stokes equations at the sphere center and polar axis. The method is flexible and efficient, with second-order accuracy in space, and has been validated through numerical examples and comparisons with existing literature.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Supavit Pokawanvit, Zhitao Chen, Zhihong You, Luiza Angheluta, M. . Cristina Marchetti, Mark J. Bowick
Summary: In this study, the dynamics of active nematic films driven by active flows on a substrate are investigated through simulations and theoretical analysis. It is found that arch patterns are stable under compressible flows and self-organize into a smecticlike pattern at high enough activity. However, under the incompressibility constraint, arch patterns become unstable.
Article
Engineering, Multidisciplinary
Nils Hoppe, Stefan Adami, Nikolaus A. Adams
Summary: Numerical investigation of compressible flows faces challenges that require high-resolution numerical schemes and high-performance computing. Fully adaptive multiresolution algorithms show promise in addressing these challenges. The use of a block-based algorithm structure allows for parallelization and modular setup.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Mechanics
Alessandro De Rosis, Enatri Enan
Summary: This paper presents a lattice Boltzmann model for the coupled Allen-Cahn-Navier-Stokes equations in three dimensions, solving equations for fluid velocity and order parameter within a general multiple-relaxation-time framework. The model demonstrates good accuracy against nine benchmark tests and successfully simulates different fluid systems.
Article
Mechanics
Yaqing Yang, Liang Pan, Kun Xu
Summary: This paper presents a high-order gas-kinetic scheme on three-dimensional unstructured meshes for compressible Euler and Navier-Stokes equations, utilizing WENO reconstruction and linear weights for improved accuracy, as well as fourth-order temporal discretization and high-order gas-kinetic schemes for solving unsteady and steady problems.
Article
Engineering, Ocean
C. Pilloton, J. Michel, A. Colagrossi, S. Marrone
Summary: Resonant three-dimensional nonlinear sloshing in a square-base basin is numerically analyzed to study swirling instability and the influence of viscosity. Four different fluids with increasing Reynolds number are tested in an oscillating tank. The study reveals a strong correlation between energy dissipation and instability, showing that water dissipates more energy during rotation compared to liquids with higher viscosity. The numerical solutions are provided using an enhanced version of the Smoothed Particle Hydrodynamics (SPH) model called ������-LES-SPH, which is suitable for simulating violent free-surface flows.
APPLIED OCEAN RESEARCH
(2023)
Article
Engineering, Mechanical
Junchao Chen, Manwai Yuen
Summary: This paper constructs two types of exact global solutions using elementary functions to describe the three-dimensional incompressible MHD equations without viscosity. These solutions correspond to a generalization of the well-known Arnold-Beltrami-Childress (ABC) flow and exhibit interesting local behaviors with infinite energy. Under special parameter values, these solutions can be reduced to those of the incompressible Euler equations.
NONLINEAR DYNAMICS
(2021)
Article
Mechanics
Yong Luo, Hao Tian, Conghai Wu, Hu Li, Yimin Wang, Shuhai Zhang
Summary: In this study, the spatial structure and time evolution of tornado-like vortices in a three-dimensional cavity are investigated using topological analysis and numerical simulation. The topology theory is extended to the curvilinear coordinate system, and two functions are derived to determine the topology structure of the flow patterns. The numerically simulated results show the presence of both bubble type and spiral type vortex breakdown, which are closely related to the vortex structure in the cross-section perpendicular to the vortex axis. A criterion based on the spatial structure characteristic is provided for identifying the two breakdown types.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mathematics, Applied
Xianpeng Hu, Yaobin Ou, Dehua Wang, Lu Yang
Summary: This article focuses on the incompressible limit of the three-dimensional compressible viscoelastic equations with arbitrary large initial velocity. Incompressibility is achieved by a large value of the volume viscosity, which differs from the low Mach number limit. To obtain uniform estimates, the estimates for the potential part and the divergence-free part of the velocity are established. As the volume viscosity tends to infinity, the dispersion associated with pressure waves disappears, but the large volume viscosity induces strong dissipation on the potential part of the velocity, forcing the flow to be almost incompressible.
ADVANCES IN NONLINEAR ANALYSIS
(2023)
Article
Mechanics
Qijie Li, Junqiang Xia, Kensuke Yokoi, Syazana Omar
Summary: This study introduces a new constrained interpolation profile conservative semi-Lagrangian method based on a novel boundary variation diminishing algorithm, which effectively reduces numerical dissipation near critical regions. By utilizing two candidate schemes, it successfully optimizes interface capturing and reconstruction of smooth solutions to eliminate numerical oscillation and diffusion, showing potential for application in a wide range of engineering problems.
Article
Computer Science, Interdisciplinary Applications
Hongyuan Lin, Chongwen Jiang, Shuyao Hu, Zhenxun Gao, Chun-Hian Lee
Summary: In this study, a disturbance region update method with preconditioning (DRUM-P) was developed for steady incompressible flows. DRUM-P achieved computational speedup and convergence improvement for compressible and incompressible flows by employing the local preconditioning technique, two high-flexible computational domains, and a modified operation of the advective domain. The proposed method was validated through eight test cases and showed remarkable efficiency and accuracy.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Computer Science, Interdisciplinary Applications
Lucie Freret, Michael Williamschen, Clinton P. T. Groth
Summary: This paper presents a parallel anisotropic block-based adaptive mesh refinement (AMR) algorithm for solving physically complex flow problems with highly anisotropic features and varying spatial and temporal scales. The algorithm utilizes a binary tree data structure for anisotropic refinement and coarsening of grid blocks, and employs a non-uniform cell representation to enhance computational efficiency.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mathematics, Applied
Joo Hyeong Han, Jae Ryong Kweon
Summary: The solutions of compressible Stokes flows with inflow jump condition can be decomposed into jump discontinuity part, contact singularity part, and smoother part, with this paper presenting a numerical scheme for each part and demonstrating their essential role in capturing the jump discontinuity behaviors. This new algorithm is believed to be critical in constructing jump discontinuity solutions.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Mathematics, Applied
Weiwei Ao, Yong Liu, Juncheng Wei
Summary: This study focuses on constructing solutions with multiple travelling vortex rings for three dimensional axisymmetric Euler flow, with large speed based on the analysis of a nonlinear elliptic equation, and the vortex rings' locations are governed by balancing systems.
PHYSICA D-NONLINEAR PHENOMENA
(2022)
Article
Nanoscience & Nanotechnology
Huai Chen, Danxun Li, Ruonan Bai, Xingkui Wang
Article
Physics, Multidisciplinary
Huai Chen, Danxun Li, Ruonan Bai, Xingkui Wang
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2018)
Article
Mechanics
Huai Chen, Zhihuan Wang, Lijun Zhu, Jianzhong Wang
