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Title: Data-driven, structure-preserving approximations to entropy-based moment closures for kinetic equations

Journal Article · · Communications in Mathematical Sciences
 [1];  [2];  [2]
  1. Univ. of Texas, Austin, TX (United States)
  2. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

In this study, we present a data-driven approach for approximating entropy-based closures of moment systems from kinetic equations. The proposed closure learns the entropy function by fitting the map between the moments and the entropy of the moment system, and thus does not depend on the spacetime discretization of the moment system or specific problem configurations such as initial and boundary conditions. With convex and C2 approximations, this data-driven closure inherits several structural properties from entropy-based closures, such as entropy dissipation, hyperbolicity, and H-Theorem. We construct convex approximations to the Maxwell–Boltzmann entropy using convex splines and neural networks, test them on the plane source benchmark problem for linear transport in slab geometry, and compare the results to the standard, entropy-based systems which solve a convex optimization problem to find the closure. Numerical results indicate that these data-driven closures provide accurate solutions in much less computation time than that required by the optimization routine.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1999103
Journal Information:
Communications in Mathematical Sciences, Vol. 21, Issue 4; ISSN 1539-6746
Publisher:
International PressCopyright Statement
Country of Publication:
United States
Language:
English

Cited By (1)

A structure-preserving surrogate model for the closure of the moment system of the Boltzmann equation using convex deep neural networks text January 2021