An Afternoon of Talks on SPH

September 25, 2018

An afternoon of talks on SPH

EEMCS Building 36 / 09.150 Dijkstrazaal, 14:45-17:00


Smoothed Particle Hydrodynamics is a computational methodology to resolve partial differential equations in Lagrangian form with clouds of mass-laden particles. First conceived for astrophysical research in the 1977, SPH has been used ever since to simulate increasingly wicked situations in fluid and solid mechanics where the meshlessness adds explaining power and/or abates operational overheads.

In SPH integral interpolants (kernels) are used to obtain 'smoothed' estimates of continuous operators (force terms) from scattered data (the particles). These estimates of the force terms determine the displacement of the particles in their turn. SPH formulations follow the classical chainwork of manipulation of continuous equations, discretization of continuous operators, and algorithmic solution. Additionally, SPH is a compute-intensive methodology, which makes ample use of hardware acceleration on single- and multi-GPU computer systems.

For this workshop we have asked three guest speakers to explain us how SPH helped them out in their research strategy; which formulation and implementation issues they experienced and overcame; which aspects are still limiting and need refinement.


Dr Giordano Lipari • Delft University of Technology, DIAM

An SPH Practical Hornbook

This very short talk will skim the surface of the SPH subject and lay out some rudiments of this methodology. The aim is to help anyone in the audience be on the same page while the floor is taken by our honoured guests.


Dr Corrado Altomare • Flanders Hydraulics Research, Antwerp / Ghent University

Employing WCSPH for modelling of sea waves and wave-structure interaction phenomena: parameter settings and uncertainties

The SPH method is becoming quite popular among researchers and practitioners to solve complex problems involving free-surface flows and multi-body interaction. As a mesh-free method, SPH allows to simulate highly nonlinear free-surface flows. Two distinguishable approaches have been developed during the last decades, namely Weakly Compressible (WCSPH) and Incompressible SPH (ISPH). Based on WCSPH, DualSPHysics is an open source model widely applied to coastal engineering and wave energy. Key issues relate to model parameter settings and model uncertainties will be treated during this talk.

 

Dr Rutger IJzermans • Shell Research and Development, Amsterdam

Modelling of deep-water waves in a restricted domain

An accurate estimate of forces exerted by extreme sea waves on offshore structures is vital to assess potential risks to structural integrity. The present work describes a method to simulate multi-modal and multi-directional sea waves with SPH. The waves are generated by moving the side boundaries of the fluid domain according to the sum of random Fourier modes, each with its own direction, amplitude and wave frequency. By carefully selecting the amplitudes and the frequencies, the ensemble of wave modes can be chosen to satisfy a standard sea wave spectrum, such as a JONSWAP or a Pierson-Moskowitz spectrum. The method is used to simulate three different extreme wave events, with generally good agreement between the simulated waves and the recorded real-life data. The potential of the method for practical situations is illustrated by a simulation of the impact of an extreme wave on a tension-leg platform.

 

Prof Stefan Luding • University of Twente, Enschede

Particle fluid coupling by SPH

We study the dispersion of an initially packed, static granular bed by the injection of a liquid jet, relevant for many industrial applications, including paint dispersion or food powder dissolution. Here we consider a model problem where the liquid jet is injected below a granular bed contained in a cylindrical cell. Two different initial conditions are considered: a two-phase case where the bed is initially fully immersed in the liquid, and a three-phase case where the bed and cell are completely dry preceding the injection of the liquid. The focus of this contribution is the simulation of these model problems using a two-way coupled SPH-DEM granular+liquid method [M. Robinson, M. Ramaioli, and S. Luding, 2014, https:///www.doi.org/10.1016/j.ijmultiphaseflow.2013.11.003].


For progress in-house research on SPH see

• Twitter https://twitter.com/sph_delft

• Youtube http://bit.ly/sph_tube



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