  In this article we review the perfect-fluid hydrodynamics with spin framework
proposed recently. This framework generalises the standard relativistic
hydrodynamics framework to include spin degrees of freedom and provides a
natural method to describe the spin polarization evolution of massive spin 1/2
particles. This formalism is based on the GLW (de Groot - van Leeuwen - van
Weert) energy-momentum tensor and spin tensor. We show here using Bjorken model
that how this spin hydrodynamics framework may be used for the determination of
the observables which describes the particle polarization measured in the
experiment.
