Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries

The performance of several engineering applications are strictly connected to the rheology working fluids and Oldroyd-B model is widely employed describe a linear viscoelastic behaviour. In present paper, buoyant flow in vertical porous layer with permeable isothermal boundaries investigated. Seepage modelled through an extended version Darcy’s law which accounts for rheology. basic stationary parallel axis describes single-cell pattern where cell has infinite height. A stability analysis such carried out determine onset conditions multicellular pattern. This performed numerically by employing shooting method. neutral curves values critical Rayleigh number evaluated different retardation time relaxation characteristics fluid. study highlights extent viscoelasticity destabilising effect on flow. For limiting case Newtonian fluid, known results available literature recovered, namely value Darcy–Rayleigh equal 197.081 corresponding wavenumber 1.05950.