Additive equivalence in turbulent drag reduction by flexible and rodlike polymers
Roberto Benzi, Emily S. C. Ching, T. S. Lo, Victor S. L'vov, Itamar Procaccia
Physical Review E
We address the "Additive Equivalence" discovered by Virk and coworkers: drag reduction affected by flexible and rigid rodlike polymers added to turbulent wall-bounded flows is limited from above by a very similar Maximum Drag Reduction (MDR) asymptote. Considering the equations of motion of rodlike polymers in wall-bounded turbulent ensembles, we show that although the microscopic mechanism of attaining the MDR is very different, the macroscopic theory is isomorphic, rationalizing the interesting experimental observations.