fuckyeahfluiddynamics:

The photos above show cross-sections through the leading edge vortices on a highly swept delta wing at angle of attack.  Flow in the photos is from the upper left to lower right. Notice how the vortices grow and develop waviness as they move downstream. When perturbations enter the vortex—for example, due to the shear between the vortex fluid and the freestream—some will grow and eventually cause a break down to turbulence, as in the lower picture. (Photo credits: R. Nelson and A. Pelletier)