Reynolds number Turbulent flow Anisotropy Basic building block Coherent state Coherent structure Complex flow Direct numerical simulations datum Drag reduction Duct flow Dumbbell model Finite extensibility Flow patterns In-pipe Kinetic energy Kinetics Large diameter Linear elastic Moderate Reynolds numbers Newtonian liquids Non linear Occurrence probability Organisational Peterlin approximation Pipe flow Poisson distribution Polymer stretching Stereo image processing Stereoscopic particle image velocimetry Tensors