In exterior of the disc of radius   the Biot-Savart law
restores the velocity field  which is induced by the vorticity  with zero-circularity and given constant velocity  at infinity.
No-slip condition for 
leads to the relations for :
where
 is the Kronecker delta, ,  are the  cartesian coordinates of .
In particular, from the no-slip condition follows orthogonality the vorticity to the kernel of the Weber's transform :