Buoyancy Modelling In Sph With Appropriate Boundary Conditions

Damien Violeau, Agnès Leroy, Martin Ferrand, Antoine Joly

Monday 29 june 2015

14:05 - 14:20h at Central America (level 0)

Themes: (T) Special session, (ST) Smoothed particle hydrodynamics and other meshfree methods

Parallel session: 2H. Special session: Smoothed Particle Hydrodynamics and other meshfree methods

Buoyancy modelling (e.g. temperature effects) are important in environmental flows. In case of complex flows, like distorted free-surface flows, complex fluid interfaces or fluid/structure interactions, Lagrangian methods make it easier to capture all the flow structures (wave breaking, fluid mixing). The purpose of the present work is to model temperature advection/diffusion coupled with turbulence through the SPH (Smoothed Particle Hydrodynamics) Lagrangian numerical method. Buoyancy is modelled with a Boussinesq approximation, the pressure being solved from a Poisson equation. Turbulence/buoyancy coupling is handled by a k–_ model including buoyancy terms. The main progress in this work is the treatment of boundary conditions (BC). For wall BC, the so-called semi-analytical approach is applied, while a new method is used to treat open (inlet/outlet) BC. This combined approach proved being very efficient, SPH providing velocity, pressure, temperature and turbulent profiles in excellent agreement with the Finite Volume method for confined flows. The 3-D extension is rather straightforward and is based on a GPU-programming for computational efficiency. Applications to confined and free-surface unsteady flows will be presented