An exponential decay function for polymer degradation in turbulent drag reduction

The mechanical degradation of high molecular weight polymers under turbulent flow conditions was investigated using a rotating disk apparatus. The validity of the empirical exponential decay function, which has been used to represent the degradation phenomenon in polymer induced turbulent drag reduction in a pipe flow, has been investigated. Results show that the single exponential decay model is not universally suitable for all polymeric drag reducers, but it effectively represents shear resistant, drag reducing agents, including the Various polysaccharides, and is also applicable in describing short time degradation behavior. (C) 2000 Published by Elsevier Science Ltd.