Onset of thermal instability in a low Prandtl number fluid with internal heat source in a porous medium

Abstract

This paper investigates the condition leading to the onset of stationary convection in a low Prandtl number horizontal fluid layer in a porous medium heated from below with internal heat source. The internal heat source is taken as directly proportional to the temperature leading to a sinusoidal temperature gradient in the fluid layer. The effects of heat generation, porosity parameter and different Prandtl numbers, Pr are presented. The results show that the onset of stationary instability is hastened by increasing values of the internal heat generation as well as increments in the Prandtl number. Further, increases in the porosity parameter delayed the onset of stationary instability.