Experimental investigation of turbulence characteristics in stirred tank with polymer as drag reducing agent using particle image velocimetry

Abstract

Abstract The effect of polymer concentration on turbulence flow field was analyzed by particle image velocimetry inside a stirred tank. With the increment of polymer concentration, the velocity gradient in the radial direction increased and the TKE and EDR rapidly decreased in the impeller region, while the velocity gradient decreased in the axial direction and the TKE and EDR first increased and then decreased in the region close to the wall. Higher polymer concentration resulted in lower turbulence intensity both in the radial and axial velocity components attributing to the weakened and restrained fluctuation intensity of the long-chain in the drag reducer polymer.