Categoria:
Seminari di Modellistica Differenziale Numerica
Data e ora inizio evento:
Data e ora fine evento:
Aula:
Sala di Consiglio
Sede:
Dipartimento di Matematica, Sapienza Università di Roma
Speaker:
Remi Abgrall (University of Zurich)
In this paper, we explore the use of the Virtual Element Method concepts to solve scalar and system hyperbolic problems on general polygonal grids. The new schemes stem from the active flux approach [4], which combines the usage of point values at the element boundaries with an additional degree of freedom representing the average of the solution within each control volume. Along the lines of the family of residual distribution schemes introduced in [1, 3] that integrate the active flux technique, we devise novel third order accurate methods that rely on the VEM technology to discretize gradients of the numerical solution by means of a polynomial-free approximation, by adopting a virtual basis that is locally defined for each element. The obtained discretization is globally continuous, and for nonlinear problems it needs a stabilization which is provided by a monolithic convex limiting strategy extended from [2]. This is applied to both point and average values of the discrete solution. We show applications to scalar problems, as well as to the acoustics and Euler equations in two dimension. The accuracy and the robustness of the proposed schemes are assessed against a suite of benchmarks involving smooth solutions, shock waves and other discontinuities.
This is a joint work with W. Boscheri, and Yongle Liu
[1] RA A combination of residual distribution and the active flux formulations or a new class of schemes that can combine several writings of the same hyperbolic problem: application to the 1d Euler equations. Commun. Appl. Math. Comput., 5(1):370–402, 2023.
[2] RA, M. Jiao, Y. Liu, and K. Wu. Bound preserving Point-Average-Moment PolynomiAl-interpreted (PAMPA) scheme: one-dimensional case. Arxiv: 2410.14292.
[3] RA, J. Lin, and Y. Liu. Active flux for triangular meshes for compressible flows problems. Beijing Journal of Pure and Applied Mathematics, 2025. Arxiv 2312.11271.
[4] T.A. Eyman and P.L. Roe. Active flux. 49th AIAA Aerospace Science Meeting, 2011.