Towards Experimental Measurements of Boundary Layer Transition at the Holloman Test Track: Initial Planning
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. 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. A set of three test track shots is to be proposed, at one year intervals, to begin to determine if the test track can make useful measurements of boundary layer transition, at least under some conditions. The present proposal requests initial funds to begin to plan this three shot test program, working in cooperation with Test Track personnel and others.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- FA95501910298
Entities
People
- Steven Schneider
Organizations
- Air Force Office of Scientific Research
- Purdue University
- United States Air Force