  One prototypical instability in granular flows is the shear-banding
instability, in which a uniform granular shear flow breaks into alternating
bands of dense and dilute clusters of particles having low and high shear
(shear stress or shear rate), respectively. In this work, the shear-banding
instability in an arbitrarily inelastic granular shear flow is analyzed through
the linear stability analysis of granular hydrodynamic equations closed with
Navier--Stokes-level constitutive relations. It is shown that the choice of
appropriate constitutive relations plays an important role in predicting the
shear-banding instability. A parametric study is carried out to study the
effect of the restitution coefficient, channel width and mean density. Two
global criteria relating the control parameters are found for the onset of the
shear-banding instability.
