Search arXivSearch

arXiv · 2607.07385

JAX-FVM: A differentiable, entropy-stable finite volume solver on unstructured meshes for compressible flows

Abstract

We present JAX-FVM, an open-source, fully differentiable finite volume method (FVM) for the two-dimensional compressible Euler and Navier-Stokes equations on unstructured triangular meshes. The solver is written entirely in JAX, so that every operation : mesh connectivity, flux evaluation, slope limiting, and time integration is just-in-time compiled, vectorised, and end-to-end differentiable through automatic differentiation (AD), and runs transparently on CPU or GPU. On the numerical side, JAX-FVM is built around an entropy-conservative Tadmor/Ismail-Roe two-point flux supplemented with entropy-variable Rusanov or Roe dissipation, second-order MUSCL reconstruction of primitive variables with least-squares gradients and Venkatakrishnan limiting, and a family of explicit (RK2-4) and matrix-free implicit (Newton, SDIRK2) time integrators whose Jacobian actions are obtained by AD. The combination of an unstructured-mesh compressible FVM with end-to-end differentiability fills a gap left by existing differentiable CFD frameworks, which are almost exclusively restricted to structured grids or spectral discretisations. We describe the governing equations, the discretisation, the software architecture, and a set of standard verification cases. The code is openly available at https://github.com/guigzair/jax_fvm.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Guillaume de Romémont. 2026-07-08. JAX-FVM: A differentiable, entropy-stable finite volume solver on unstructured meshes for compressible flows. https://arxiv.org/abs/2607.07385

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Fully spectral scheme for the linear BGK equation on the whole space

In this article, we design a fully spectral method in both space and velocity for a linear inhomogeneous kinetic equation with mass, momentum and energy conservation. We focus on the linear BGK equation with a confinement potential $Φ$, even if the method could be applied to different collision operators. It is based upon the projection on Hermite polynomials in velocity and orthonormal polynomials with respect to the weight $e^{-$Φ$}$ in space. The potential $Φ$ is assumed to be a polynomial. It is, to the author's knowledge, the first scheme which preserves hypocoercive behavior in addition to the conservation laws. These different properties are illustrated numerically on both quadratic and double well potential.

math.NA

Inverse inequalities for kernel-based approximation on bounded domains and Riemannian manifolds

This paper establishes inverse inequalities for kernel-based approximation spaces defined on bounded Lipschitz domains in $\mathbb{R}^d$ and compact Riemannian manifolds. While inverse inequalities are well-studied for polynomial spaces, their extension to kernel-based trial spaces poses significant challenges. For bounded Lipschitz domains, we extend prior Bernstein inequalities, which only apply to a limited range of Sobolev orders, to the full range of lower and upper orders, and derive Nikolskii inequalities that bound $L_\infty$ norms by $L_2$ norms. For compact Riemannian manifolds, we focus on restricted kernels, which are defined as the restriction of positive definite kernels from the ambient Euclidean space to the manifold, and prove their counterparts.

math.NA

Error Estimates for Hyperbolic Scaling Limits of Linear Kinetic Models on Networks

This paper studies linear discrete kinetic models on networks and their asymptotic behavior in the small Knudsen number limit. For coupling conditions at an n-edge junction under a symmetric formulation, we introduce a change of variables that reformulates the system into n independent initial-boundary value problems. The asymptotic expansions are then constructed and rigorously justified by deriving an error estimate based on the energy method.

math.NA