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Stability Analysis for HIFiRE ExperimentsThe HIFiRE-1 flight experiment provided a valuable database pertaining to boundary layer transition over a 7-degree half-angle, circular cone model from supersonic to hypersonic Mach numbers, and a range of Reynolds numbers and angles of attack. This paper reports selected findings from the ongoing computational analysis of the measured in-flight transition behavior. Transition during the ascent phase at nearly zero degree angle of attack is dominated by second mode instabilities except in the vicinity of the cone meridian where a roughness element was placed midway along the length of the cone. The growth of first mode instabilities is found to be weak at all trajectory points analyzed from the ascent phase. For times less than approximately 18.5 seconds into the flight, the peak amplification ratio for second mode disturbances is sufficiently small because of the lower Mach numbers at earlier times, so that the transition behavior inferred from the measurements is attributed to an unknown physical mechanism, potentially related to step discontinuities in surface height near the locations of a change in the surface material. Based on the time histories of temperature and/or heat flux at transducer locations within the aft portion of the cone, the onset of transition correlated with a linear N-factor, based on parabolized stability equations, of approximately 13.5. Due to the large angles of attack during the re-entry phase, crossflow instability may play a significant role in transition. Computations also indicate the presence of pronounced crossflow separation over a significant portion of the trajectory segment that is relevant to transition analysis. The transition behavior during this re-entry segment of HIFiRE-1 flight shares some common features with the predicted transition front along the elliptic cone shaped HIFiRE-5 flight article, which was designed to provide hypersonic transition data for a fully 3D geometric configuration. To compare and contrast the crossflow dominated transition over the HIFiRE-1 and HIFiRE-5 configurations, this paper also analyzes boundary layer instabilities over a subscale model of the HIFiRE-5 flight configuration that was tested in the Mach 6 quiet tunnel facility at Purdue University.
Document ID
20120011835
Document Type
Conference Paper
Authors
Li, Fei (NASA Langley Research Center Hampton, VA, United States)
Choudhari, Meelan M. (NASA Langley Research Center Hampton, VA, United States)
Chang, Chau-Lyan (NASA Langley Research Center Hampton, VA, United States)
White, Jeffery A. (NASA Langley Research Center Hampton, VA, United States)
Kimmel, Roger (Air Force Research Lab. Wright-Patterson AFB, OH, United States)
Adamczak, David (Air Force Research Lab. Wright-Patterson AFB, OH, United States)
Borg, Matthew (Booz-Allen and Hamilton, Inc. United States)
Stanfield, Scott (Spectral Energies, LLC Dayton, OH, United States)
Smith, Mark S. (NASA Dryden Flight Research Center Edwards, CA, United States)
Date Acquired
August 26, 2013
Publication Date
June 25, 2012
Subject Category
Fluid Mechanics and Thermodynamics
Report/Patent Number
NF1676L-13774
Meeting Information
42nd AIAA Fluid Dynamics Conference and Exhibit(New Orleans, LA)
Funding Number(s)
WBS: WBS 599489.02.07.07.04.11.01
Distribution Limits
Public
Copyright
Public Use Permitted.

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