Journal of Theoretical
and Applied Mechanics

50, 4, pp. 943-951, Warsaw 2012

Thermal instability of a heterogeneous oldroydian viscoelastic fluid heated from below in porous medium

Pardeep Kumar, Hari Mohan
The thermal instability of an Oldroydian heterogeneous viscoelastic fluid in a porous medium is considered. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For stationary convection, the medium permeability and density distribution are found to have a destabilizing effect. The dispersion relation is also analyzed numerically. Sufficient conditions for non-existence of overstability are also obtained.
Keywords: thermal instability; heterogeneous Oldroydian viscoelastic fluid; porous medium; linear stability theory