A small amount of polymer additives can cause substantial reduction in the energy
dissipation and friction loss of turbulent flow. The problem of polymer-induced drag …

The current work qualitatively surveys the phenomenon of polymer drag reduction from the
standpoint of the salient coherent motions in the near-wall region of wall-bounded turbulent …

Polymer additives can substantially reduce the drag of turbulent flows and the upper limit,
the so-called state of 'maximum drag reduction'(MDR), is to a good approximation …

We present an experimental investigation of turbulent drag reduction with flexible and rigid
polymer solutions in a 2: 1 aspect ratio rectangular duct. The flexible polymer is partially …

We experimentally compared the drag-reduced turbulent channel flow of three different
additives: a flexible polymer, a rigid polymer and a surfactant. A high drag reduction (HDR) …

The presence of a tiny amount of polymers (a few parts per million) in a fluid dramatically
reduces turbulent drag. For this reason, polymer additives have been proposed to be used …

Two kinds of nonlinearities coexist in viscoelastic fluid flows, ie, inertia and elasticity, which
can engender different types of chaotic states including inertial turbulence (IT), drag …

Turbulent drag can be reduced by the use of anti-turbulent additives, which are often
associated with significant economic benefits. For half a century turbulent drag reduction has …

The elasto-inertial turbulence (EIT) of viscoelastic fluid is induced by the interaction between
elastic instability and flow inertia. The recent discovery of the EIT regime enables new …

The current theories on the mechanism for polymer drag reduction (DR) are generally
applicable for long-chain flexible polymers that form viscoelastic solutions. Rigid polymer …