Decaying compressible turbulence in ALE simulations

A high-order Arbitrary Lagrangian-Eulerian (ALE) finite-element code developed at Lawrence Livermore National Laboratory, called Marbl, is used to study decaying compressible turbulence generated by the non-Boussinesq lock exchange problem. The lock exchange is a prototype for the study of pyroclastic flows from volcanic eruptions, turbidity currents in the ocean, fires in semi-enclosed spaces, and a wide range of other geophysical and industrial flows. Gravity currents initially drive the entrainment of a denser fluid into a lighter one; these gravity currents have been studied in a wide variety of simulations and laboratory experiments, which provide a benchmark for our simulations. As the gravity currents interact with the walls, the flow becomes fully turbulent. When it is well mixed and chaotic, we proceed to characterize the decaying turbulence using single-particle Lagrangian statistics. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-2008661.