Solutions of the initial value problem for dispersions of solid particles in fluidized beds, slurries, sand placement in fracture oil reservoirs, cleaning of drill cuttings from oil wells, and other applications are solved without approximations beyond those inherent in simulations. These are needed to handle the large nonlinear and linear algebraic equations that arise in this investigation. These solutions consume the largest percentage of the simulation time. 1,109 particles flowing in a Newtonian fluid in a channel. The mixture is pumped upwards against gravity.
Color shows the stream function.
The collaboration of these two communities, which traditionally speak different languages, has given rise to an interdisciplinary group that communicates with ease across disciplinary boundaries. The first, which uses a moving unstructured body fitted grid, is the only numerical package anywhere that can move solid particles in a viscoelastic fluid in direct simulation. The second is an elegant package that uses a fixed grid in which particles are represented by a field of Lagrange multipliers associated with the constraint of rigid body motion. The fixed structured grid offers opportunities for using rapid solvers that are ideally suited for parallel implementation. Performance results obtained on two parallel computational platforms, an SGI Origin 2000 and a Cray T3E, indicate that routine fine tuning of various kernels results in efficient utilization of the parallelism offered by these architectures.