Velocity profile statistics in a turbulent boundary layer with slot-injected polymer

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

The modification of a flat-plate turbulent boundary layer resulting from the injection of drag-reducing polymer solutions through a narrow inclined slot into the near-wall region of the flow has been studied. Two-component coincident laser-Doppler velocity profile measurements were taken with a free-stream velocity of 4.5 m/s with polymer injection, water injection, and no injection. Polyethylene oXide solutions at concentrations of and 1025 w.p.p.m. were injected. These data are complemented by polymer concentration profile measurements that were taken using a laser-induced-fluorescence technique. Also, integrated skin friction measurements were made with a drag balance for a range of polymer injection conditions and free-stream velocities. The immediate effects of polymer injection are a deceleration of the flow near the wall, a dramatic decrease of the vertical r.m.s. velocity fluctuation levels and the Reynolds shear stress levels, and a mean velocity profile approaching Virk's asymptotic condition. These effects relaX substantially with increasing streamwise distance from the injection slot and become similar to the effects observed for dilute homogeneous polymer flows.

Original languageEnglish (US)
Pages (from-to)435-466
Number of pages32
JournalJournal of Fluid Mechanics
Volume238
Issue number435
DOIs
StatePublished - Jan 1 1992

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Velocity profile statistics in a turbulent boundary layer with slot-injected polymer'. Together they form a unique fingerprint.

Cite this