text: 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 :