EXPERIMENTAL MEASUREMENTS OF BOUNDARY-LAYER TRANSITION ON A BLUNT OGIVE AT THE HOLLOMAN TEST TRACK
Abstract
Accurate prediction of boundary-layer transition remains critical to the design of hypersonic vehicles, due to the dramatic effect of transition on heat transfer, boundary-layer separation, and aerodynamic control authority. Although much progress has been made in understanding the basic mechanisms of transition, vehicle designers usually predict transition using simple correlations. The uncertainties in these correlations are large for a new hypersonic vehicle, generating high levels of development risk and tendencies towards less-effective but conservative designs. Furthermore, no single ground test can simulate all aspects of hypervelocity transition, and nearly all ground tests are corrupted by the high levels of test-section noise in conventional hypersonic wind tunnels. Mechanism-based prediction methods are needed for effective design of flight vehicles, and measurements of the mechanisms of transition are needed as part of a larger team effort to develop and validate these methods. For three or more decades, the rocket-sled test track at Holloman Air Force Base has been considered for use as a possible ground-test facility for transition measurements. As with ballistic ranges, the test-track should not suffer tunnel-wall radiated acoustic noise. However, track vibration, test-article angle-of-attack oscillations and atmospheric dust are all possible test-track disturbance sources that may not exist in the actual flight path of typical DoD weapon systems. Test-track models are much larger than those possible in ballistic ranges, although test-track maximum velocities are lower. The test track altitude is also much lower than the altitude of typical DoD flight vehicles, raising scaling questions which will vary with weapon-system trajectory, vehicle geometry and roughness.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502210101
Entities
People
- Steven Schneider
Organizations
- Air Force Office of Scientific Research
- Purdue University
- United States Air Force