Visualization of compressible lock-exchange flow in a tall box

This simulation of the lock-exchange problem was performed in a box that is 6 cm in length and 36 cm in height. The left half of the box contains a heavy fluid, while the right side of the box contains a lighter fluid; their initial density ratio is 0.1, making this a problem that requires a compressible hydrodynamics treatment. Here we have examined the evolution of density currents at a low ambient pressure of 10 dyn/cm². This simulation was produced with the higher order finite element code Marbl, developed at LLNL. Here Marbl solves the single-fluid compressible hydrodynamics equations using an Arbitrary Lagrangian Eulerian (ALE) method. The grid is 60x360, and level 2 refinement is used; the finite element method is third order. Time integration was accomplished using a second-order Runge Kutta method. Artificial viscosity is used, but otherwise this is an implicit large-eddy simulation (ILES).

This work was done under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Neither the United States government nor Lawrence Livermore National Security, LLC, nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or Lawrence Livermore National Security, LLC. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC, and shall not be used for advertising or product endorsement purposes. LLNL-MI-871988.