A combined approach for investigating the effects of large wing sweep and unsteady wing motion on transition and separation- Flight experiments, wind tunnel experiments and simulations
Abstract
Advances in composite materials manufacturing enable the use of high aspect ratio wings with low induced-drag that can dramatically increase range and endurance. High aspect ratio wings are inherently more flexible, requiring understanding of the impact of structural motion on flow physics. Sudden bubble bursting due to laminar separation (LSB) can lead to abrupt leading-edge stall. In almost all published research on LSBs, especially in the context of structural motion, the effect of sweep on the fundamental fluid dynamics has been entirely neglected. The proposed research program will address this critical void by employing a combined approach consisting of free-flight and wind-tunnel experiments as well as high-fidelity simulations and stability theory. A wing with a large sweep angle of 45 degrees is proposed because our preliminary investigations with 45 degrees sweep indicate that crossflow instability will be strong enough to affect transition in the boundary-layer upstream of the LSB and-or inside it. By varying the flight speeds and AoA, conditions can be established for which the transition and separation mechanisms are dominated by crossflow instability, or for which both traveling and crossflow instabilities are present simultaneously.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 14, 2024
- Source ID
- FA95502310708
Entities
People
- Hermann Fasel
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Arizona