[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

This paper assesses some recent trends in the novel numerical meshless method smoothed particle hydrodynamics, with particular focus on its potential use in modelling free-surface flows. Due to its Lagrangian nature, smoothed particle hydrodynamics (SPH) appears to be effective in solving diverse fluid-dynamic problems with highly nonlinear deformation such as wave breaking and impact, multi-phase mixing processes, jet impact, sloshing, flooding and tsunami inundation, and fluid–structure interactions. The paper considers the key areas of rapid progress and development, including the numerical formulations, SPH operators, remedies to problems within the classical formulations, novel methodologies to improve the stability and robustness of the method, boundary conditions, multi-fluid approaches, particle adaptivity, and hardware acceleration. The key ongoing challenges in SPH that must be addressed by academic research and industrial users are identified and discussed. Finally, a roadmap is propose...

Smoothed particle hydrodynamics (SPH) for free-surface flows: past, present and future

Smoothed particle hydrodynamics method for fluid flows, towards industrial applications: Motivations, current state, and challenges

Comparative study on accuracy and conservation properties of two particle regularization schemes and proposal of an optimized particle shifting scheme in ISPH context

The article aims at providing an up-to-date review on several latest advancements related to particle methods with applications in coastal and ocean engineering. The latest advancements corresponding to accuracy, stability, conservation properties, multiphase multi-physics multi-scale simulations, fluid-structure interactions, exclusive coastal/ocean engineering applications and computational efficiency are reviewed. The future perspectives for further enhancement of applicability and reliability of particle methods for coastal/ocean engineering applications are also highlighted.

/pdf/on-the-state-of-the-art-of-particle-methods-for-coastal-and-4emfnigqnn.pdf

On the state-of-the-art of particle methods for coastal and ocean engineering

Simulations of bubble entrainment into a stationary Gaussian vortex are performed by using the combined particle tracking method (PTM) and boundary element method (BEM). Before the bubble is captured by the vortex core, oscillation and migration of the quasi-spherical nucleus are solved by using improved RP equation and the momentum theorem in the Lagrangian reference frame simultaneously, and the trajectory of the nucleus presents a kind of reduced helix shape. After captured by the vortex core, the bubble grows immediately and moves and deforms along the vortex core axis. The non-spherical evolution and deformation of the bubble is simulated by adopting a mixed Eulerian-Lagrangian method. The output of quasi-spherical stage is taken as the input of non-spherical stage, and all the behaviors of the entrained bubble can be simulated such as inception, motion, deformation and split. Numerical results agree well with published experimental data. On this basis, the influences of various factors such as viscosity, surface tension, buoyancy are studied systemically. Hopefully the results from this paper would provide some insight into the control on vortex bubble entrainment.

Influences of different forces on the bubble entrainment into a stationary Gaussian vortex

Prolonged simulation of near-free surface underwater explosion based on Eulerian finite element method

Experimental study on dynamic buckling of submerged grid-stiffened cylindrical shells under intermediate-velocity impact

On the interaction between bubbles and the free surface with high density ratio 3D lattice Boltzmann method

A meshfree approach to the simulation of the large deformation of a curved shell by the reproducing kernel particle method (RKPM) is presented. Since the kinematic description is based on the Mindlin–Reissner shell theory, only one layer of particles is needed to model the shell and the time increment is not limited by the shell thickness. The reproducing interpolation function is adopted to discretize the kinematic quantities of the shell; thus, the spatial discretization is independent of the finite element mesh, so it can address large deformations without mesh distortion. The governing equation of an arbitrary curved shell is derived in detail based on the principle of virtual power, for which reasonable simplifications have been taken. The Lagrangian kernel and stress points are adopted in the calculation, which are sufficient to eliminate instability. Several numerical examples are performed, verifying the reliability and numerical accuracy of the RKPM shell model. No locking is observed in the numerical solutions.

A-Man Zhang

Papers

Influences of different forces on the bubble entrainment into a stationary Gaussian vortex

Prolonged simulation of near-free surface underwater explosion based on Eulerian finite element method

Experimental study on dynamic buckling of submerged grid-stiffened cylindrical shells under intermediate-velocity impact

On the interaction between bubbles and the free surface with high density ratio 3D lattice Boltzmann method

A thick shell model based on reproducing kernel particle method and its application in geometrically nonlinear analysis