When the convective energy transport is efficient, the temperature gradient can be shown to be rather close to the critical Schwarzchild value. So the stellar structure models are not sensitively dependent on the details of turbulence. This is lucky. Stellar structure happens to be one of the most solid and well-understood areas of modern astrophysics, even though our understanding of turbulence in the interiors of stars is very primitive. Turbulence may play an important role in transporting and distributing angular momentum in different parts of a rotating star.
Angular velocity varies inside the Sun in a complicated fashion.
It is believed that the Reynolds stress associated with turbulence in the solar convection is what causes this distribution of angular momentum, although we are very far from having a proper understanding of the subject. We shall further see that turbulence is the cause of the dynamo effect, which produces magnetic fields in astronomical objects. In contrast to the stellar structure theory which is insensitive to the details of turbulence, the theory of stellar rotation and the dynamo theory depend crucially on some subtle aspects of turbulence. In these subjects, one usually proceeds with some suitable mean equations like the ones discussed in the previous section. The theory of rotating stars and the theory of magnetic stars are still at unsatisfactory stages of development.