Split-film anemometry in a drag-reducing solution

<p>"Turbulence measurements were made in the tube flow of mineral oil and a 0.2% solution of polyisobutylene in the same oil. Velocity profiles, axial and radial turbulence intensities, and axial and radial energy spectra were obtained in both fluids using a split-film anemometer probe. In addition, velocity profiles and axial turbulence intensities were obtained in oil using a 0.001-in. cylinder probe, a cone probe and a parabolic-wedge probe. The measurements were made in a one-inch tube at a constant fluid temperature of 30.0°C, in the Reynolds-number range of 4,800 to 50,000.</p> <p>Four factors influenced the results in a greater manner than previously thought or reported. These were: calibration, intermittent contamination of the probes, eddy shedding from cylindrical probes and electrical ground loops. Errors resulting from underestimating the importance of these factors could account for the discrepancies and large scatter of data existing throughout the literature of turbulence measurements.</p> <p>Very good agreement and repeatability of results were obtained with the split-film and 0.001-in. probes. The cone and parabolic probes tended to give erroneous results because of their relatively large size.</p> <p>Axial turbulence intensities in oil peaked at the same distance from the wall, y⁺ ~ 18, for all Reynolds numbers, attaining lower levels with increasing Reynolds numbers. The radial intensities peaked at the same level for all Reynolds numbers, at distances from the wall in the region 0.15 < y/R < 0.3.</p> <p>Accurate hot-film anemometry measurements in fresh polymer solutions were found to be unfeasible because of rapid changes in heat transfer rate caused by minute polymer degradation.</p> <p>Measurements in a degraded polymer solution gave both raised and lowered axial turbulence intensities as compared to oil, with raised intensities always obtained at the center of the tube. The radial turbulence intensities obtained were always lower than in oil throughout the entire cross section of the tube"-- Abstract, pp. ii-iii</p>

Name thesis:degree_name

Ph. D. in Chemical Engineering

Grantor

University of Missouri--Rolla

Year dc:date.available

2016

Author dc:creator

• Chosnek, Jack

• Chemical Engineering

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/260

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-1262