Flow of a viscoelastic fluid between eccentric cylinders: impact on flow stability

Abstract The flow of an elastic fluid between eccentric cylinders was experimentally and theoretically examined. A purely elastic flow instability in the eccentric cylinder flow geometry has been discovered 1 , 2 . The focus of this paper is an investigation of how the characteristics of the base flow ultimately influence the flow stability. The velocity profiles of a Boger fluid between eccentric cylinders was measured by Laser Doppler velocimetry and compared to the theoretical predictions from a lubrication analysis. The base flow stress profiles between eccentric cylinders were calculated by integrating the polymeric stresses along streamlines. It is shown that the convection of polymeric stresses alter the hoop stresses in the flow. Implications of this observation to the flow stability are discussed.