NASA Technical Paper 2256 - CAFE Foundation

i,
dinates are given in table 8• The composite airframe was built using full-depth foam
characteristics core with fiberglass of theskins airplane on theareforward shownin wingtable and 7• graphite The wing skinsairfoil on thedesign aft wing. coor-
: Experiments conducted with this airplane included determination of transition loca-
l!i!: tions on portions of the lower (£orward) and upper (aft) wings both inside and outside
of the propeller slipstream, The indicated airspeed for these tests was
_ 165 knots at a density altitude of 10 000 ft. The corresponding unit Reynolds number_
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_•i_ during these tests was 1,38 × 106 ft -I.
i i Gates Learjet Model 28/29 Longhorn.- Higher speed _light experiments were con-
ducted with a twin-engine, turbojet, 10-seat business airplane. (See fig. 9.) The
wing was constructed of integrally Stiffened milled aluminum skins with leading-edge
contour modifications made of sanded filler material• Aircraft physical details are
presented in table 9. Experiments conducted with this airplane included visual
determination-of transition locations on the wing and winglet at high subsonic Mach
numbers. The Mach number range for-these tests was 0•55 to 0.70 at density altitudes i
of 15 500 to 16 00 ft. The maximum unit Reynolds number during testing was f
3.08 x 106 ft -I. i
Cessna P-210 Centurion.- The pressurized six-passenger business airplane shown
in figure 10 was utilized for transition measurements on conventional metal surfaces.
Physical characteristics of this single-engine, retractable-gear airplane are pre-
sented in table 10. The wing incorporates an NACA 64-series airfoil; the horizontal
tail uses a symmetric NACA airfoil varying in thickness from 5 to 9 percent. The
airframe was constructed of riveted aluminum skins, ribs, and stringers• A limited
amount of body-putty filling and sanding was done on half-of the region of the left
wing, which was painted dark to facilitate sublimating chemical observations. The
filling and sanding illustrated in figure 11 were done to reduce surface roughness
and waviness in the region of a spanwise row of flush dimpled rivets near the leading
edge. Experiments conducted with this airplane included observations of transition
locations on the dark portion of the left wing, c)n the horizontal stabilizer, and on
the propeller spinner. The Calibrated airspeed range for these tests was 139 co
154 knots. The maximum unit Reynolds number during testing was I .48 × 106 ft -1 •
Beech 24R Sierra.- Flight experiments were Conducted with the four-seat, low-
wing, single-engine, retractable-gear airplane shown in figure 12. Geometric details
are presented in table 11. The wing design incorporates an NACA 63-series airfoil.
The propeller uses a Clark Y airfoil• The bonded-aluminum-skin outboard portion of
the wing was selected for sublimating chemical _transition visualization. In addi-
tion, transition observations were made on the vertical tail and on the propeller.
_ The calibrated airspeed for these tests was 133 knots, the propeller was operating at
2700 rpm, and the maximum unit Reynolds number during testing was I .38 × I0 u ft-'.
obtain--_ _u_-n_ _ e_eriments conducted with the high-performance, single-
engine, retractable-gear airplane shown in figure 13. Geometric details are
If! Bellanca Skyrocket II•- Detailed data on an NACA 632-215 NLF airfoil was
presented in table 12• The airframe was built of fiberglass, aluminum-honeycomb
composite sandwich structure. Experiments with the Skyrocket include visual determi-
ne, nation of wing transition locations, including the effect of propeller slipstream• A
for section drag calculations, chordwise static pressures for analysis of section
__!ii scanning lift and pressure measurement distributions, system and was boundary-layer utilized to velocity measure airfoil profiles wake insideprofiles and
outside the propeller slipstream. Figure 14 illustrates the instrumentation instal-
I lation A detailed description of these experiments is contained in reference 31
,i I • •
, The maximum calibrated airspeed for these tests was 176 knots for a maximum unit