Angular momentum transation -- matter exchange

http://grblogscn.blogspot.com/2006/11/blog-post_25.html
Here is some aspects on the angular momentum transition. Another idea that the taking photons as the origin of viscousness, is also failed.

Now, one more another idea: particles to act the actor of viscousness. The transfer of particles (by thermal random movement? or some other methods) will bring the angular momentum from inner to outside.