Dryden Technical Report Server
From NTRS: Locate an electronic (PDF) copy of the document.
- AIRPLANE AS INDICATED BY WING-SURFACE TUFTS AT SUBCRITICAL AND SUPERCRITICAL SPEEDS , Research Memorandum
Authors: De E. Beeler
Report Number: NACA-RM-L6L03
Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
Abstract: Results are presented in this report of the air-flow behavior over the wing of an XP-51 airplane including photographs of tuft attached to the wing surface and chordwise pressure distributions. A comparison of tuft studied is made of the flight results with those obtained from wind-tunnel tests. The results indicate that steady flow is obtained over the wing until the critical speed has been exceeded by about 0.04 to 0.05 in Mach numbers. At higher Mach numbers the flow is unsteady and becomes very rough and turbulent over the rear 50 percent of the chord after the limit maximum pressure coefficient has been reached. Observation of surface tufts alone without benefit of prevailing pressure distributions may indicate separated flow before separation actually occurs. Comparisons made of the flight and wind-tunnel data show a similar tuft behavior throughout the Mach number range.
Distribution/Availability: Unclassified - Unlimited
Availability:
From NTRS: Locate an electronic (PDF) copy of the document.
Report Date: April 1947
- WAKE MEASUREMENTS BEHIND A WING SECTION OF A FIGHTER AIRPLANE IN FAST DIVES , Technical Note
Authors: De E. Beeler and George Gerard
Report Number: NASA-TN-1190
Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
Abstract: Wake measurements made in a vertical plane behind a wing-section of a fighter airplane are presented for a range of Mach number up to 0.78. Since evidences of reverse flow were found in a large part of the surveys—possibly because of interference of the rake support—the computed profile-drag coefficients are considered to be only qualitative. The results showed that the large increase in drag coefficient beyond critical Mach number indicated by wind-tunnel tests was also obtained under flight conditions and that the wake width was extended sharply when shock was encountered. The wake extension occurred first at the upper surface since the highest local velocity was obtained on that surface. The large increase in drag coefficient for the wing section tested did not occur until after the critical Mach-number had been exceeded by approximately 0.05. Comparison of the profile-drag measurements with total airplane drag measurements showed
that the large increases in drag in both cases started to occur at the same value of Mach number. The results further indicated that wake measurements made in three dimensional-flow after shock had occurred cannot, in general, be interpreted in terms of section profile-drag coefficient because of the existence of the strong lateral flow indicated by tuft behavior in the dead-air region behind the shock.
Distribution/Availability: Unclassified - Unlimited
Availability:
From NTRS: Locate an electronic (PDF) copy of the document.
Report Date: March 1947
|
