Drag-Reducing Polymer Molecular Weight Effects on Turbulent Diffusion for Uniformly Distributed Polymer Injection.

摘要

The effect of polymer molecular weight on turbulent diffusion and drag-reduction was investigated over a uniformly distributed polymer injection area. The purpose of the experiments,carried out in a porous wall pipe flow facility,was to determine optimum values of polymer molecular weight and injection mass flux for attaining maximum skin-friction reduction over a distributed injection area and to investigate associated turbulent diffusion characteristics. It was found for this type of polymer supply system,which provided polymer directly to the required wall shear stress region,that the optimum molecular weight was approximately an order of magnitude less than that normally used in skin-friction reduction applications with homogeneous solutions and localized injection. (Modified author abstract)