MAHESH DATTA DHONE
Resolution of TIP Vortices by grid-based, grid-free and coupled methods using CFD (Doktorverteidigung, Januar 2020)
Video von Dr.-Ing. Sina Samarbakhsh
Computations by MEHRDAD KAZEMI
LES calculation of the plate under the angle of attack of 18 deg. Vortex structures detected by the Q-criterion and colored by mean velocity.
Results of prediction of the turbulent kinetic energy by different research organisations
Results were presented during the Tokyo 2015 Workshop on CFD in Ship Hydrodynamics. Different cross sections S4 and S7 behind JBC test case ship. Lines along which the distributions are presented are shown on each picture. LeMoS results were obtained using the method described in papers:
LEAPFROG Movement of two Ring Vortices
The LEAPFROG movement is modeled using the Finite Volume Method (OpenFOAM) and the Computational Vortex Element Method (CVM). In the frictionless flow, the leafprog movement continues until the convective instability destroys the vortex. One vortex runs through the next, the radius of which decreases as the speed increases. The radius of the next vortex increases and the speed decreases. The first ring moves through the second. The process is then repeated. The non-viscous CVM reproduces this process over a longer period of time. Numerical diffusion in FVM transforms the two vertebrae into individual ones. The situation has not improved by increasing the resolution and reducing the physical viscosity. The numerical diffusion FVM is too high.
Collision of two Vortex Rings in a Smooth Flow
Because of the self-induction, the rings move towards each other. Due to the mutual influence, they grow. This process runs in a smooth flow until the convective instability destroys the vortices. The movement is modeled using the Finite Volume Method (OpenFOAM) and the Computational Vortex Element Method (CVM). The non-viscous CVM reproduces this process for a long time. The numerical diffusion in FVM transforms the two vertebrae into individual ones. The numerical diffusion FVM is too high.