## Team for Advanced Flow Simulation and Modeling |

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## Contaminant Dispersion Around an M1 Battle TankIn this problem, contaminant dispersion around a M1 battle tank is simulated on a CRAY T3D. This simulation is carried out in two stages. First, the full Navier-Stokes equations are solved to obtain the velocity field around the tank. This velocity field is used in the second stage in the time-dependent contaminant advection-diffusion equation to obtain the concentration of contaminant around the tank. In this computation, the tank is stationary and is subject to a wind speed of 20 miles per hour. The contaminant is released in front of the tank from a point source with constant strength. The Reynolds, Prandtl, and Lewis numbers in this computation are 1.6 million, 0.72, and 1.0 respectively. The computations are carried out on an unstructured mesh consisting of 100,379 nodes and 527,586 tetrahedral elements. Approximately, 0.4 million coupled, nonlinear equations are solved at every pseudo-time step to obtain the steady-state flow field, and 0.1 million equations are solved at every time step to obtain the transient solution of contaminant dispersion. The time-history of the contaminant concentration obtained from such simulations can be used to study visibility during battlefield conditions. The top image below shows the pressure distribution on the tank surface corresponding to the steady-state. The bottom images show the contaminant concentration at two instants, in each case viewed from two different angles. The movie show the contaminant dispersing around the tank.
The unstructured mesh generator, flow solver, and flow visualization software (based on BoB, Ensight, and Wavefront) were developed by the T*AFSM. ## References: 1. T.J.R. Hughes, T.E. Tezduyar and A.N. Brooks, "Streamline Upwind
Formulations for Advection-Diffusion, Navier-Stokes, and First-order
Hyperbolic Equations", 2. T.E. Tezduyar and D.K. Ganjoo,
"Petrov-Galerkin Formulations with Weighting Functions Dependent Upon
Spatial and Temporal Discretization: Applications to Transient
Convection-Diffusion Problems", 3. T.E. Tezduyar and J. Liou, "Adaptive Implicit-Explicit Finite
Element Algorithms for Fluid Mechanics Problems", 4. T.E. Tezduyar, "Stabilized Finite Element Formulations for
Incompressible Flow Computations", 5. T. Tezduyar, S. Aliabadi, M. Behr, A. Johnson, V. Kalro and M.
Litke, "High Performance Computing Techniques for Flow Simulations",
Chapter 10 in |