CFD investigation of dense phase pneumatic conveying at a pipeline enlargement

► The effect of an expansion in pneumatic conveying pipeline bore investigated. ► A dense phase 'plug' of fine particulate material modelled by 3D CFD. ► An abrupt expansion may result in a plug which having increased aeration. ► In the gradual expansion case the plug was seen to collapse and elongate. ► The abrupt and gradual expansion geometries resulted in recirculation zones.