The dynamical shear instability is an important mixing process in the advanced stages of the evolution of massive stars .
We calculated different models of 15 M _ { \odot } with an initial rotational velocity , \upsilon _ { ini } = 300 km/s to investigate its efficiency .
We found that the dynamical shear instability has a timescale shorter than Oxygen burning timescale and that it slightly enlarges the convective zones and smoothens the omega gradients throughout the evolution .
However , its effect is too localized to slow down the core of the star .