Dissimilar Turbulent Momentum and Heat Transfer Associated with Viscoelastic Vibration in Channel Flow

This experimental study on the momentum and heat transfer in drag-reducing turbulent channel flow of surfactant solution, i.e., viscoelastic fluid, has revealed a viscoelastic vibration (VEV) as a novel type of ordered turbulent motion in the wall vicinity where the elastic energy is transformed into turbulent kinetic energy. The VEV is a wave-like motion of low-frequency modes in the streamwise direction and causes zero average Reynolds shear stress. However, thermal diffusion occurs continuously due to the movement of a fluid lump owing to the VEV via the additional action of pressure.(c) 2023 Elsevier Ltd. All rights reserved.