  The global static stability of a Starling Resistor conveying non-Newtonian
fluid is considered. The Starling Resistor consists of two rigid circular tubes
and axisymmetric collapsible tube mounted between them. Upstream and downstream
pressures are the boundary condition as well as external to the collapsible
tube pressure. Quasi one-dimensional model has been proposed and a boundary
value problem in terms of nondimensional parameters obtained. Nonuniqueness of
the boundary value problem is regarded as static instability. The analytical
condition of instability which defines a surface in parameter space has been
studied numerically. The influence of fluid rheology on stability of
collapsible tube is established.
