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Adrian Kolb

Publications and source records attributed to Adrian Kolb.

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MultiWave: A computational laboratory for adaptive numerical methods approximating hyperbolic balance laws

The MultiWave C++-framework for adaptive numerical methods approximating hyperbolic balance laws is presented. MultiWave has been designed as a computational laboratory where new mathematical concepts can be quickly implemented and tested. Starting from the mathematical background and proceeding to the low-level implementation details, the realisation of a discontinuous Galerkin method with multiresolution-based grid adaptation is demonstrated. The design choices, in particular regarding the modularity that allows one to extend the code reusing existing infrastructure, is discussed. Scaling studies on a distributed-memory machine show that the framework retains its efficiency up to large rank counts, and that multiresolution-based adaptivity reduces the cost per time step by orders of magnitude compared to the uniform-grid computation at the order of accuracy of the full reference discretisation.

math.NA

Radially symmetric solutions of the ultra-relativistic Euler equations in several space dimensions

The ultra-relativistic Euler equations for an ideal gas are described in terms of the pressure, the spatial part of the dimensionless four-velocity and the particle density. Radially symmetric solutions of these equations are studied in two and three space dimensions. Of particular interest in the solutions are the formation of shock waves and a pressure blow up. For the investigation of these phenomena we develop a one-dimensional scheme using radial symmetry and integral conservation laws. We compare the numerical results with solutions of multi-dimensional high-order numerical schemes for general initial data in two space dimensions. The presented test cases and results may serve as interesting benchmark tests for multi-dimensional solvers.

math-ph

Multiresolution-analysis for stochastic hyperbolic conservation laws

A multiresolution analysis for solving stochastic conservation laws is proposed. Using a novel adaptation strategy and a higher dimensional deterministic problem, a discontinuous Galerkin (DG) solver is derived. A multiresolution analysis of the DG spaces for the proposed adaptation strategy is presented. Numerical results show that in the case of general stochastic distributions the performance of the DG solver is significantly improved by the novel adaptive strategy. The gain in efficiency is validated in computational experiments.

math.NA