Experimental Investigation of Precursors of Dynamic Stall at Very High Reynolds Numbers
Abstract
The proposed research project leverages the combination of a unique high pressure flow facility and development of novel high-resolution instrumentation to perform a systematic study of dynamic stall over an unprecedented range of Reynolds numbers, including very high Reynolds numbers. The primary research objective of the proposed research project is to reveal and characterize early spatiotemporal signatures and structures of dynamic stall, with a focus on signatures of these structures that can be measured on, or close to, the skin of the lifting surface for on-board real-time control. The effect of Reynolds number, three-dimensionality, as well as geometric and kinematic features on the underlying physical mechanisms will be investigated and characterized. The combination of high Reynolds numbers and statistically unsteady conditions makes attempts to accurately simulate these flows, experimentally or numerically, extremely challenging since it is difficult to induce dynamic events at high Reynolds numbers with timescales large enough such that they can be studied with sufficient resolution. The use of highly pressurized air, up to 238 bar, enables Reynolds numbers to be increased 200 times without increasing velocity, thus keeping time scales large. This allows highly dynamic events to be created without requiring unreasonable accelerations or angular velocities. As part of the proposed research project, a unique PIV system will be integrated into the high pressure facility and high resolution micro-hot-film sensor arrays will be designed, manufactured and evaluated, advancing our ability to probe these kinds of flows. The proposed research will yield new and much needed knowledge about the details of dynamic stall at high Reynolds number, as well as the spatiotemporal dynamic response of the boundary layer to the changing flow distribution stemming from a change in the angle of attack.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 02, 2022
- Source ID
- W911NF2210187
Entities
People
- Marcus Hultmark
Organizations
- Army Contracting Command
- Princeton University
- United States Army