racoon II

- refined adaptive computations with object-oriented numerics -

racoon II is a framework for time-dependant mesh-adaptive computations on structured grids, developed jointly by Jürgen Dreher (St. Andrews, Scotland) and Rainer Grauer (Bochum, Germany).

The goal of this project is to create an environment that allows the advanced numerical investigation of time-dependent phenomena in fluid dynamics and plasma physics which develop strongly localized structures, e.g. turbulent flows, magnetic reconnection and current sheet formation, by means of adaptive mesh refinement (AMR).

Key design aspects in racoon II are

a high degree of flexibility through the separation of the physical problem definition, numerical methods and data handling routines, and
the efficient use of shared-, distributed- and mixed memory architectures, e.g. SMP clusters, in high performance computing through explicit dynamic load-balancing strategies

The mesh refinement is based on a regular block-based partitioning with a Hilbert-type space-filling curve ordering for distribution and load balancing among separate address spaces. Robust and simple high precision numerical schemes like CWENO are used as a basis for the time integration, while an object-oriented design and implementation in C++ facilitates the realization of the design goals mentioned above.

At the moment, a full-featured two-dimensional implementation is available and being applied to problems in solar plasma physics. It is used on the UKMHD cluster at St. Andrews (5 Nodes with 4 Dec Alpha CPUs each) and on Intel or Alpha based Linux machines.