Buoyant flow instability induced by a uniform internal heat source in a vertical annular porous layer

The buoyancy–induced parallel flow in a vertical cylindrical porous layer with annular cross–section is analysed. A radial thermal gradient caused by uniformly distributed heat source assumed to induce the buoyant flow. boundaries are modelled as isothermal and permeable an external fluid reservoir. onset of convective instability analysed linearising governing equations for perturbations. parameters driving heat–source Rayleigh number ratio between internal radius radius. Neutral stability curves critical values number, perturbation wave angular frequency computed numerically. It shown that axisymmetric modes form most dangerous type instability.