Reynolds number roughness and pressure gradient effects for energy efficient drag reduction in wall turbulence
Abstract
This project aims to transform our ability to reduce and control turbulent skin-friction drag in practice. Overcoming the effects of this drag accounts for most of the fuel consumption and greenhouse gas emissions of ships, submarines and aircraft. This proposal investigates the mechanism responsible for the high-Reynolds number skin-friction drag reduction strategy reported recently by Marusic et al. (2021, Nature Communications, 12, 5805). The strategy involves imposing relatively low-frequency streamwise travelling waves of spanwise velocity at the wall, to actuate the drag generating outer-scales. This approach has proven to be more energy-efficient than the conventional method of directly targeting the drag producing inner-scales, which typically requires actuation at higher frequencies. Besides uncovering its physical mechanism, the proposal also seeks to extend this novel approach to high Reynolds number boundary layers exposed to hydrodynamically rough surfaces and pressure gradients. Such conditions are ubiquitous in naval applications, but the effects are still poorly understood.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2023
- Source ID
- N629092312068
Entities
People
- Ivan Marusic
Organizations
- Office of Naval Research
- United States Navy
- University of Melbourne