vriphys17

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https://diglib.eg.org/handle/10.2312/2631244

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Browsing vriphys17 by Subject "fluid simulation"

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    Approximate Air-Fluid Interactions for SPH
    (The Eurographics Association, 2017) Gissler, Christoph; Band, Stefan; Peer, Andreas; Ihmsen, Markus; Teschner, Matthias; Fabrice Jaillet and Florence Zara
    Computing the forces acting from a surrounding air phase onto an SPH free-surface fluid is challenging. For full multiphase simulations the computational overhead is significant and stability issues due to the high density ratio may arise. In contrast, the air-fluid interactions can be approximated efficiently by employing a drag equation. Here, for plausible effects, the parameterization is important but challenging. We present an approach to calculate the parameters of the used drag equation in a physically motivated way. We approximate the deformation and occlusion of particles to determine their drag coefficient and exposed surface area. The resulting effects are validated by comparing them to the results of a multiphase SPH simulation. We further show the practicality of our approach by combining it with different types of SPH solvers and by simulating multiple, complex scenes.
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    Moving Least Squares Boundaries for SPH Fluids
    (The Eurographics Association, 2017) Band, Stefan; Gissler, Christoph; Teschner, Matthias; Fabrice Jaillet and Florence Zara
    The paper shows that the SPH boundary handling of Akinci et al. [AIA 12] suffers from perceivable issues in planar regions due to deviations in the computed boundary normals and due to erroneous oscillations in the distance computation of fluid particles to the boundary. In order to resolve these issues, we propose a novel boundary handling that combines the SPH concept with Moving Least Squares. The proposed technique significantly improves the distance and normal computations in planar boundary regions, while its computational complexity is similar to Akinci's approach. We embed the proposed boundary handling into Implicit Incompressible SPH in a hybrid setting where it is applied at planar boundaries, while Akinci's technique is still being used for boundaries with complex shapes. Various benefits of the improved boundary handling are illustrated, in particular a reduced particle leakage and a reduced artificial boundary friction.