Fluid-object interactions in interior ballistics

A fluid-object interaction model for an interior ballistics problem is pres ented. The fluid is a compressible gas and is modeled using the Deformable- Spatial-Domain/Stabilized-Space-Time (DSD/SST) formulation. The objects can move axially within the model domain, and their motion is determined by th e fluid pressure forces and collisions with other objects and rigid boundar ies. The model is implemented assuming axisymmetry of the geometry and the flow field. The fluid mesh is composed of structured regions of quadrilater al elements and unstructured regions of triangular elements. The structured elements are used near the surface of the objects in order to better resol ve the boundary layer, while the unstructured elements are used elsewhere i n the domain. As the objects move, the mesh deformation needed to accommoda te these motions takes place only in the unstructured parts of the mesh. Ap plication to an interior ballistics problem is presented and discussed. (C) 2000 Elsevier Science S.A. All rights reserved.