A complete original study of the linear temporal instability analysis of two viscous and
immiscible fluids enclosed in a rigid cylinder rotating about its axis and separated by a
cylindrical interface is performed for the case of higher density fluid located in the annulus.
The results of the present contribution fill the lack of an overall assessment of the system
behavior due to the increase of both the analytical difficulties and the number of the
governing parameters when the several physical effects are all included. The analysis is …