## Team for Advanced Flow Simulation and Modeling |

For more information: |
## Gas Impinging on a LiquidThe objective of this test problem is to demonstrate the computational capability of simulating wave formation. This capability will be used to obtain a better understanding of fundamental physics behind wave formation caused by the wave undercut mechanism and the subsequent formation of droplets. In this problem, incompressible gas with with velocity of 50 m/s at an angle of 30 degrees from vertical hits flammable liquid, which is initially at rest. Initially, the liquid occupies the lower quarter of a cube, with dimensions 10 cm on each side. The liquid is assumed to be 45.3 times heavier than the gas and the Reynolds number based on the cube size, injection velocity and the viscosity of the gas is one million. The computation is carried out on a Thinking Machines CM-5 using a structured mesh made of 50x50x50 hexahedral elements. The time increment was set to 0.05 and in every time stop, approximately one million coupled nonlinear equations are solved to obtain the pressure and velocity fields. To keep track of interface between the gas and liquid, we use an automatic mesh moving scheme to move the finite element mesh. Using this scheme, more than 400,000 equations are solved to update the finite element mesh at every time step. The top image below shows the pressure distribution on the surface of the liquid at t = 0.050 s. The middle image shows the surface of the liquid at t = 0.000 s and the bottom at t = 0.075 s. The flow solver, and flow visualization software (based on Pager) were developed by 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. T.E. Tezduyar, M. Behr, S. Mittal and A.A. Johnson "Computation of
Unsteady Incompressible Flows with the Stabilized Finite Element
Methods--Space-Time Formulations, Iterative Strategies and Massively
Parallel Implementations", 5. G. Wren, S. Ray, S. Aliabadi and T. Tezduyar, "Simulation of Flow
Problems with Moving Mechanical Components, Fluid-Structure Interactions
and Two-Fluid Interfaces", 6. T. Tezduyar and Y. Osawa, "Methods for Parallel Computation of
Complex Flow Problems", |