| Wed February 28th 2018 16:00 – 17:00 ZH286 | Seminar | Boiling Taylor-Couette Turbulence Rodrigo Ezeta |
Details:The presence of air bubbles in high Reynolds number Taylor-Couette (TC) flow has proven to be successful when reducing the drag in the flow. Approximately, 40% drag reduction (DR) is achieved when the volume fraction is 4%. In this study, we explore the drag reduction mechanism in TC flow using vapor bubbles instead. To do so, a low-boiling point liquid is used as the fluid phase, which boils at 34 degrees when the pressure is atmospheric. By fixing the speed of the cylinders and varying the temperature continuously, the boiling point is reached, nucleation of vapor bubbles begins which results in a uniform distribution of the bubbles along the axis. Our first experiments reveal 40% drag reduction when the volume fraction is 6% at a Reynolds number of approximately one million. | ||
