A semi-implicit scheme for 3D free surface flows with high-order velocity reconstruction on unstructured Voronoi meshes

2012 ◽  
Vol 72 (6) ◽  
pp. 607-631 ◽  
Author(s):  
W. Boscheri ◽  
M. Dumbser ◽  
M. Righetti
Keyword(s):  
Free Surface ◽  
Free Surface Flows ◽  
High Order ◽  
Implicit Scheme ◽  
Surface Flows

scholarly journals A High-Order Conservative Semi-Lagrangian Solver for 3D Free Surface Flows with Sediment Transport on Voronoi Meshes

2020 ◽  
Author(s):  
Matteo Bergami ◽  
Walter Boscheri ◽  
Giacomo Dimarco
Keyword(s):  
Free Surface ◽  
Sediment Transport ◽  
Numerical Scheme ◽  
Control Volume ◽  
Free Surface Flows ◽  
High Order ◽  
Time Step ◽  
Reconstruction Procedure ◽  
Surface Flows ◽  
Lagrangian Scheme

AbstractIn this paper, we present a conservative semi-Lagrangian scheme designed for the numerical solution of 3D hydrostatic free surface flows involving sediment transport on unstructured Voronoi meshes. A high-order reconstruction procedure is employed for obtaining a piecewise polynomial representation of the velocity field and sediment concentration within each control volume. This is subsequently exploited for the numerical integration of the Lagrangian trajectories needed for the discretization of the nonlinear convective and viscous terms. The presented method is fully conservative by construction, since the transported quantity or the vector field is integrated for each cell over the deformed volume obtained at the foot of the characteristics that arises from all the vertexes defining the computational element. The semi-Lagrangian approach allows the numerical scheme to be unconditionally stable for what concerns the advection part of the governing equations. Furthermore, a semi-implicit discretization permits to relax the time step restriction due to the acoustic impedance, hence yielding a stability condition which depends only on the explicit discretization of the viscous terms. A decoupled approach is then employed for the hydrostatic fluid solver and the transport of suspended sediment, which is assumed to be passive. The accuracy and the robustness of the resulting conservative semi-Lagrangian scheme are assessed through a suite of test cases and compared against the analytical solution whenever is known. The new numerical scheme can reach up to fourth order of accuracy on general orthogonal meshes composed by Voronoi polygons.

High‐order divergence‐free velocity reconstruction for free surface flows on unstructured Voronoi meshes

2019 ◽  
Vol 90 (6) ◽  
pp. 296-321 ◽  
Author(s):  
Walter Boscheri ◽  
Giuseppe Roberto Pisaturo ◽  
Maurizio Righetti
Keyword(s):  
Free Surface ◽  
Free Surface Flows ◽  
High Order ◽  
Surface Flows ◽  
Divergence Free
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