Quantum Hydrodynamics
It is a branch of condensed matter physics that studies hydrodynamic-like systems which exhibit quantum mechanical behaviour.
One of the important areas of study in quantum hydrodynamics is that of Superfluidity.
The equations of quantum hydrodynamics are called Madelung equations, and they are just quantum Euler Equations, which are Schrodinger's equations in the Bohmian interpretation written with hydrodynamic variables.