| Autor: |
Saeki Takashi, Kaide Aya |
| Jazyk: |
English<br />French |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
MATEC Web of Conferences, Vol 333, p 02002 (2021) |
| Druh dokumentu: |
article |
| ISSN: |
2261-236X |
| DOI: |
10.1051/matecconf/202133302002 |
| Popis: |
The objective of this study is to clarify the flow characteristics of drag-reducing flow and to elucidate the mechanism underlying this phenomenon. The surfactant and counter ion we used were Lipothoquad O/12 and sodium salicylate, respectively. The drag reduction rate (DR%) was measured by using a recirculating system with a diameter of 25.6 mm. We also measured the flow characteristics of the surfactant solutions with different concentrations and temperatures by using particle image velocimetry (PIV). From the experimental results, DR% at an average velocity of 2.0 m/s increased from 0 to 68% as the temperature increased from 10 to 40 °C at a constant concentration of surfactant (300 mg/L). From the velocity contour plot obtained from PIV, we found that the thickness of the lower-velocity region of the drag-reducing flow near the pipe wall was thick at 20 °C, whereas vortex motions seemed controlled at 30 °C. On the other hand, the lower-velocity region thickened as the concentration of the surfactant increased at 25°C. Even if the same level of drag-reducing effects occurred, the flow patterns were quite different depending on the concentration and temperature. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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