I propose to study the effects of central black holes on the structure of galaxies, the evolution of chaotic orbits in triaxial potentials, stellar interactions with massive black holes and tidal distortion of dwarf galaxies. The study will involve newly developed parallel algorithms for efficient simulation of self-gravitating systems, including continuing development of new hybrid parallel algorithms and analysis tools for parallel computers. Implementation will be on Cray T3D/T3E, the special purpose HARP processor at the IoA, and the proposed Cambridge Large Scale Computing Facility. Objectives will be a survey of the orbital properties of a family of triaxial galaxy models, with a central black hole, comparison with observations, and efficient implementation of new parallel algorithms. Specifically, I will port a Poisson solver to the T3D/T3E and hybridise the code with a direct N-body solver using the HARP, and develop associated parallel and serial analysis software.