Acceleration is the key to drag reduction in turbulent flow

• 成果类型: Article
• 署名作者: Ding, Liuyang; Sabidussi, Lena F.; Holloway, Brian C.; Hultmark, Marcus; Smits, Alexander J.
• 署名单位: Princeton University; Intellectual Ventures
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12541
• DOI: 10.1073/pnas.2403968121
• 发表日期: 2024-10-22
• 关键词: direct numerical-simulation; oscillatory wall-motion; channel flow

摘要

A turbulent pipe flow experiment was conducted where the surface of the pipe was oscillated azimuthally over a wide range of frequencies, amplitudes, and Reynolds numbers. The drag was reduced by as much as 35%. Past work has suggested that the drag reduction scales with the velocity amplitude of the motion, its period, and/or the Reynolds number. Here, we find that the key parameter is the acceleration, which greatly simplifies the complexity of the phenomenon. This result is shown to apply to channel flows with spanwise surface oscillation as well. This insight opens potential avenues for reducing fuel consumption by large vehicles and for reducing energy costs in large piping systems.