Comparison of Wind-Tunnel and Flight-Measured Base Pressures from the Sharp-Leading-Edge Upper Vertical Fin of the X-15 Airplane for Turbulent Flow at Mach Numbers from 1.5 to 5.0. Technical Report NASA Technical Note TN D-6348, Research Engineering, NASA Dryden Flight Research Center
Goecke, Sheryll A. (1971) Comparison of Wind-Tunnel and Flight-Measured Base Pressures from the Sharp-Leading-Edge Upper Vertical Fin of the X-15 Airplane for Turbulent Flow at Mach Numbers from 1.5 to 5.0. Technical Report NASA Technical Note TN D-6348, Research Engineering, NASA Dryden Flight Research Center.
Full text available as: |
Abstract
Pressures measured at six locations on the base of the sharp-leading-edge upper vertical fin of the X-15 airplane during the power-off portion of eight flights are compared with previous flight data obtained from a blunt-leading-edge fin, theory, and wind-tunnel data. The flight and wind-tunnel base pressure ratios for the Mach number range from 1.5 to 5.0 are presented as a linearized function of turbulent boundary-layer height and base width by using a Mach-number-dependent factor derived in the study. The resulting curve seems to provide another criterion for determining whether flow is laminar or turbulent. The difference between base pressure and free-stream pressure for any specific Mach number of the study is found to be a linear function of both free-stream pressure and dynamic pressure. Data from the sharp-leading-edge upper vertical fin agree with data from the blunt-leading-edge upper vertical fin. The flight data show the variation in pressure across the base to be negligible.
| EPrint Type: | Other |
|---|---|
| Keywords: | Base pressure, Drag, Separated flow, X-15 airplane |
| Subjects: | (01 - 09) Aeronautics: (05) Aircraft Design, Testing And Performance Aircraft/Project: X-15 |
| ID Code: | 807 |
| Deposited On: | 14 March 2006 |
| Additional Information: | 40 pages. |
