Experimental Studies of Instability and Transition in a Mach-6 Quiet Tunnel
Abstract
Accurate prediction of boundary-layer transition remains critical to the design of hypersonicvehicles, due to the dramatic effect of transition on heat transfer, boundary-layer separation,and aerodynamic control authority. Although much progress has been made in understandingthe basic mechanisms of transition, vehicle designers usually predict transition usingsimple correlations. The uncertainties in these correlations are large for a new hypersonicvehicle, generating high levels of development risk and tendencies towards less-effective butconservative designs. Furthermore, no single ground test can simulate all aspects of hypervelocitytransition, and nearly all ground tests are corrupted by the high levels of test-sectionnoise in conventional hypersonic tunnels. Mechanism-based prediction methods are neededfor effective design of flight vehicles, and quiet-tunnel measurements of the mechanisms oftransition are needed as part of a larger team effort to develop and validate these methods.Quiet-flow wind tunnels are intended to replicate the low noise conditions of actual flightat hypersonic speed. The Boeing/AFOSR Mach-6 Quiet Tunnel (BAM6QT) at PurdueUniversity is the larger of two U.S. hypersonic cold-flow tunnels that achieve quiet flowto moderate Reynolds numbers. Funding is here requested for a continuing team of 4-5Ph.D. students to perform experimental measurements in the BAM6QT, with two studentshaving partial funding from the NDSEG program. The students are to study instabilityand transition: (1+2) due to the crossflow instability and (3) the second-mode instability,along with (4) instability and transition in the separated boundary layer on a generic bodyflap. At times, some funding is also allocated to student (5) to work on improving thecharacterization of the wind-tunnel flow properties.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 09, 2018
- Source ID
- FA95501710419
Entities
People
- Steven Schneider
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Virginia