## Team for Advanced Flow Simulation and Modeling |

For more information: |
## Large-Scale Fluid-Particle InteractionsThe mathematical modeling in these simulations is based on the time-dependent Navier-Stokes equations governing the flow around the particles and Newton's law of motion governing the 3D dynamics of the particles with the fluid forces acting on these particles calculated from the flow field. In these simulations, while the mesh partitioning, flow computations, and mesh movements are performed on a 512-node CM-5, the mesh generation and projection is accomplished on a 20-processor SGI Onyx system. The two platforms communicate via a HiPPI channel. The spheres, in addition to interacting with the fluid, interact and sometimes collide with each other and with the tube wall. We simulated two cases: with the size of the spheres random in one case and uniform in the second. In both cases, the simulation is started with the spheres distributed randomly in the tube. The mesh sizes during these simulations reach 1.2 million tetrahedral elements (resulting in approximately 2.6 million coupled, nonlinear equations to be solved at each time step), and the number of time steps is around 800 for each simulation. The average Reynolds number is approximately 40 in both cases. The figure here shows the random-sized spheres at four different instants during the simulation. These simulations show how the advanced computational methods developed, together with modern parallel computing platforms, enable us to carry out this difficult class of simulations at levels that would have been unthinkable a few years ago. This simulation tool can be used to help understand the behavior of fluid-particle mixtures which are used in many practical applications. The unstructured mesh generator, flow solver, and flow visualization software (based on Wavefront) were developed by the T*AFSM.
## References: 1. T.E. Tezduyar, "Stabilized Finite Element Formulations for
Incompressible Flow Computations", 2. T.E. Tezduyar, M. Behr and J. Liou, "A New Strategy for
Finite Element Computations Involving Moving Boundaries and
Interfaces--The DSD/ST Procedure: I. The Concept and the Preliminary
Numerical Tests", 3. T.E. Tezduyar, M. Behr, S. Mittal and J. Liou, "A New
Strategy for Finite Element Computations Involving Moving Boundaries
and Interfaces--The DSD/ST Procedure: II. Computation of Free-surface
Flows, Two-liquid Flows, and Flows with Drifting Cylinders",
4. A.A. Johnson and T.E. Tezduyar, "Simulation of Multiple
Spheres Falling in a Liquid-Filled Tube", 5. A.A. Johnson and T.E. Tezduyar, "3D Simulation of
Fluid-Particle Interactions with the Number of Particles Reaching
100", 6. T. Tezduyar, "CFD Methods for Three-Dimensional Computation
of Complex Flow Problems", 7. A. Johnson and T. Tezduyar, "Advanced Mesh Generation and
Update Methods for 3D Flow Simulations", 8. T. Tezduyar and Y. Osawa, "Methods for Parallel Computation
of Complex Flow Problems", 9. A. Johnson and T.
Tezduyar, "Methods for 3D Computation of Fluid-Object Interactions in
Spatially-Periodic Flows", |