Computational investigation of negatively buoyant jets

We present computational results on the stability of negatively buoyant jets at various Richardson numbers and injection angles. The results show a critical Richardson number that is the boundary between stable and unstable behavior. The critical Richardson number is seen to vary with injection angle. The computational results also reveal the mechanisms leading to instability and shedding of oil ring structures. The computational tool is a 3D GPU-accelerated MPI-parallel two-phase flow solver. The governing equations are solved using the two-step project method in the finite volume context. The fluid interfaces are tracked using the volume-of-fluid method. The pressure Poisson solver is accelerated using GPUs, which provides an average acceleration factor of 5 in 3D parallel simulations.