Onset of convection near a point source of heat and gravity

Onset of thermal convection near a point source of heat and gravity was studied. Development of unidirectional flow due to thermal instability was predicted by an analytical solution. Far-field approximation were used where the distance from the central body was much larger than the radius of the body. A striking symmetry resulting in an unidirectional buoyancy driven flow from a spherical symmetric state was predicted.