  On the basis of the intimate relation between Nambu dynamics and the
hydrodynamics, the hydrodynamics on a non-commutative space (obtained by the
quantization of space), proposed by Nambu in his last work, is formulated as
``hydrodynamics of granular material''. In Part 1, the quantization of space is
done by Moyal product, and the hydrodynamic simulation is performed for the so
obtained two dimensional fluid, which flows inside a canal with an obstacle.
The obtained results differ between two cases in which the size of a fluid
particle is zero and finite. The difference seems to come from the behavior of
vortices generated by an obstacle. In Part 2 of quantization, considering
vortex as a string, two models are examined; one is the ``hybrid model'' in
which vortices interact with each other by exchanging Kalb-Ramond fields (a
generalization of stream functions), and the other is the more general ``string
field theory'' in which Kalb-Ramond field is one of the excitation mode of
string oscillations. In the string field theory, Altarelli-Parisi type
evolution equation is introduced. It is expected to describe the response of
distribution function of vortex inside a turbulence, when the energy scale is
changed. The behaviour of viscosity differs in the string theory, being
compared with the particle theory, so that Landau theory of fluid to introduce
viscosity may be modified. In conclusion, the hydrodynamics and the string
theory are almost identical theories. It should be noted, however, that the
string theory to reproduce a given hydrodynamics is not a usual string theory.
