Abstract
Turbulence transport features in a heated drag-reducing surfactant solution (CTAC, 30wppm) channel flow was investigated by simultaneously measuring velocity and temperature fluctuations in the thermal boundary layer. Measurement was made at inlet fluid temperature of 304 K and at three Reynolds numbers (based on channel height, bulk velocity and solvent viscosity): 3.5 × 104, 2.5 × 104 and 1.5 × 104. Structural analysis showed that the drag-reducing additives inhibited the motions associated with ejections of low-momentum fluid away from the wall and sweeps of high-momentum fluid toward the wall (the second and fourth quadrant motion respectively) but had no obvious effect on the outward motion of high-momentum fluid and wall-ward motion of low-momentum fluid (the first and third quadrant motion respectively). The depression of wall-normal turbulent heat flux was due to the decreased contributions of the second and fourth quadrant motions.
Original language | English |
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Pages (from-to) | 965-973 |
Number of pages | 9 |
Journal | International Journal of Heat and Mass Transfer |
Volume | 48 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2005 Feb |
Externally published | Yes |
Keywords
- Channel flow
- Drag reduction
- Heat transfer reduction
- Quadrant analysis
- Surfactant solution
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes