A parallel-GPU code for asteroid aggregation problems with angular particles

The paper presents a numerical implementation of the gravitational N-body problem with contact interactions between non-spherically shaped bodies. The work builds up on a previous implementation of the code and extends its capabilities. The number of bodies handled is significantly increased through the use of a CUDA/GPU-parallel octree structure. The implementation of the code is discussed and its performance are compared against direct N2integration. The code features both smooth (force-based) and non-smooth (impulse-based)methods, as well as a visco-elastic non-smooth method, to handle contact interaction betweenbodies. The numerical problem of simulating “rubble-pile” asteroid gravitational aggregation processes is addressed. We discuss the features of the problem and derive criteria to set up the numerical simulation from the dynamical constraints of the combined gravitationalcollisional problem. Examples of asteroid aggregation scenarios that could benefit from suchimplementation are finally presented.