Using of Hybrid Cluster Systems for Modeling of a Satellite and Plasma Interaction by the Molecular Dynamics Method
This article deals with a model of interaction between a positively charged microsatellite and thermal space plasma. The model is based on the method of molecular dynamics (MMD). The minimum possible number of particles necessary for modeling in the simplest geometric problem formulation for a microsatellite in the form of a sphere 10 cm in diameter is ten million. This value is determined by the plasma parameters, including the value of the Debye radius, which is the basis for estimating the spatial dimensions of the modeling domain.
For the solution, MPI and CUDA technologies are used in the version of one MPI process per node. An intermediate layer in the form of multithreading, implemented on the basis of the C++ library of threads, is also used, this provides more flexible control over the management of all kinds of node memory (video memory, RAM), which provides a performance boost. The GPU optimizes the use of shared memory, records the allocation of registers between threads and the features associated with calculating trigonometric functions.
The results of numerical simulation for a single-ion thermal plasma showed significant changes in the spatial distribution of the concentration around the satellite, which depends on three main parameters - the temperature of the plasma components, the velocity of the satellite relative to the plasma and the potential of the spacecraft. The presence of a region of reduced ion concentration behind the satellite and the region of condensation in front of it is shown.
KeywordsParallel computing Thermal space plasma Charged satellite Molecular dynamics method
This work was made by support of Russian Foundation for Basic Research, grant 18-01-00394.
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