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A Coupling Strategy for Modelling Dynamics of Moored Floating Structures
Published in David M Kelly, Aggelos Dimakopoulos, Pablo Higuera, Advanced Numerical Modelling of Wave Structure Interactions, 2021
Tristan de Lataillade, Aggelos Dimakopoulos, Chris Kees, Lars Johanning
In this work, the free surface is tracked by using a coupled level set/VOF method (Kees et al., 2011). This approach consists of the following steps: The air volume fraction αa is calculated according to the following transport equation written in conservative form: ∂αa∂t+∇αauf=0The distance from the free surface ϕsdf is calculated according to the non-conservative form of the level set transport relation: ∂ϕsdf∂t+u∇ϕsdf=0 where ϕsdf is a signed distance function taking negative values in the water phase and positive values in the air phase. After being transported by Equation (3), ϕsdf is not a true signed distance function anymore and must be corrected in order to satisfy the eikonal relation: ‖∇ϕsdf‖=1 which can be recovered by keeping the interface where ϕsdf = 0 fixed and using a pseudo-steady state solution approach (Sussman et al., 1994).The signed distance function is then corrected by the VOF solution from Equation (2) to ensure mass conservation, according to the procedure presented in Kees et al. (2011).The corrected signed distance function ϕsdf is then used to recalculate the air volume fraction αa with a smoothed Heaviside function. This step is performed to ensure that αa remains sharp along the interface.
Interactive CNC simulation using distance fields
Published in International Journal of Computer Integrated Manufacturing, 2018
Allan Yoshio Hasegawa, Roberto Silvio Ubertino Rosso, Marcos de Sales Guerra Tsuzuki
where is the shortest distance between P and . When P is a point on the surface of , then (Shirley and Marschner 2009). SDF uses a signed-distance function to indicate whether the point is inside or outside the object (Frisken and Perry 2006).