  Acoustic microstreaming due to an oscillating microbubble is analytically
investigated to obtain the circular streaming motion adjacent to a nearby wall.
Classical theory due to Nyborg is carefully derived in the radial coordinates.
The theory is used to obtain the flow field and the vortical motion caused by
the microbubble motion. The length of the vertices are decreasing when the
microbubble is excited at distances close to the rigid wall, while the maximum
shear stress is increasing.
