2D flow around a square скачать в хорошем качестве

2D flow around a square

Low resolution DNS using the projection method based on the "Stable Fluids" algorithm of Jos Stam. Here I have improved it to be 4th order in space with a two-stage pressure correction, significantly reducing false diffusion. 10% vorticity confinement was used to energise the vorticity at all scales to simulate a higher Reynolds number "turbulent" flow (recall there is no real turbulence in 2D due to the absence of vortex tube stretching and tilting since all vorticity vectors are in the same plane). Coded in VB from scratch, no external libraries. Colouring represents the concentration of a passive scalar continuously replenished on the surface of the object and advected with the local flow. Note the Kelvin-Helmholtz instability on the shear layer immediately after the leading sharp edges creating loads of vorticity that is shed into the wake. Try to track some of these intense vortices and watch how they dance with eachother and zip around, particularly when they collide with the no slip wall and break apart into dipoles.