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Mcghee, R. J.

Publications and source records attributed to Mcghee, R. J..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

A new multipoint thin-film diagnostic technique for fluid dynamic studies

A multielement hot-film sensor has been developed with closely-spaced elements (2.5 mm) in the streamwise direction. In addition to boundary-layer transition detection, the output of these sensors can reveal the locations of boundary-layer separation and reattachment by a 180 deg phase difference in the 0-200-Hz frequency bandwidth between sensor elements on each side of either the separation or reattachment point. This paper describes the features of multielement hot-film sensor arrays and discusses results from their application to a number of low-speed and transonic airfoil tests.

Sewall, W. G.↗
NASA NTRS1987

Literature review and experimental results for a cylinder with perforations and protrusions at high Reynolds numbers

The NASA Langley Low Turbulence Pressure Tunnel has been used to conduct an experimental study of the flow around a series of circular cylinders; the models used consisted of a baseline, smooth cylinder together with a cylinder that could be reconfigured with six different arrangements of two types of surface irregularity. Mean lift and drag forces were measured on all seven model configurations, and correlations were made between unsteady pressure in the wake region and fluctuating lift forces, in order to identify coherent structures.

Jones, G. S.↗
NASA NTRS1987

Wind-tunnel test results of airfoil modifications for the EA-6B

Wind-tunnel tests have been conducted (to determine the effects on airfoil performance for several airfoil modifications) for the EA-6B Wing Improvement Program. The modifications consist of contour changes to the leading-edge slat and trailing-edge flap to provide a higher low-speed maximum lift with no high-speed cruise-drag penalty. Airfoil sections from the 28- and 76-percent span stations were selected as baseline shapes with the major testing devoted to the inboard airfoil section (28-percent span station). The airfoil modifications increased the low-speed maximum lift coefficient between 20 and 35 percent over test conditions of 3 to 14 million chord Reynolds number and 0.14 to 0.34 Mach number. At the high-speed test conditions of 0.4 to 0.80 Mach number and 10 million chord Reynolds number, the modified airfoils had either matched or had lower drag coefficients for all normal-force coefficients above 0.2 as compared to the baseline airfoil. At normal-force coefficients less than 0.2, the baseline (original) airfoil had lower drag coefficients than any of the modified airfoils.

Sewall, W. G.↗
NASA NTRS1986

Wind tunnel testing of low-drag airfoils

Results are presented for the measured performance recently obtained on several airfoil concepts designed to achieve low drag by maintaining extensive regions of laminar flow without compromising high-lift performance. The wind tunnel results extend from subsonic to transonic speeds and include boundary-layer control through shaping and suction. The research was conducted in the NASA Langley 8-Ft Transonic Pressure Tunnel (TPT) and Low Turbulence Pressure Tunnel (LTPT) which have been developed for testing such low-drag airfoils. Emphasis is placed on identifying some of the major factors influencing the anticipated performance of low-drag airfoils.

Harvey, W. Donald↗
NASA NTRS1986

The Langley Research Center's Low-Turbulence Pressure Tunnel

The Low-Turbulence Pressure Tunnel (LTPT), located at the Langley Research Center, is a relatively old wind tunnel which was recently rehabilitated and which has several unique capabilities. A brief history of the LTPT will be presented along with its present operating characteristics. Its unique capabilities will be described and data will be presented to demonstrate these capabilities. Finally, a suggestion will be made for the construction of a new improved facility incorporating and extending the capabilities of the present LTPT.

Stainback, P. C.↗
NASA NTRS1984

Experimental Results for a Flapped Natural-laminar-flow Airfoil with High Lift/drag Ratio

Experimental results have been obtained for a flapped natural-laminar-flow airfoil, NLF(1)-0414F, in the Langley Low-Turbulence Pressure Tunnel. The tests were conducted over a Mach number range from 0.05 to 0.40 and a chord Reynolds number range from about 3.0 x 10(6) to 22.0 x 10(6). The airfoil was designed for 0.70 chord laminar flow on both surfaces at a lift coefficient of 0.40, a Reynolds number of 10.0 x 10(6), and a Mach number of 0.40. A 0.125 chord simple flap was incorporated in the design to increase the low-drag, lift-coefficient range. Results were also obtained for a 0.20 chord split-flap deflected 60 deg.

Mcghee, R. J.↗
NASA NTRS1984

Recent modifications and calibration of the Langley low-turbulence pressure tunnel

Modifications to the Langley Low-Turbulence Pressure Tunnel are presented and a calibration of the mean flow parameters in the test section is provided. Also included are the operational capability of the tunnel and typical test results for both single-element and multi-element airfoils. Modifications to the facility consisted of the following: replacement of the original cooling coils and antiturbulence screens and addition of a tunnel-shell heating system, a two dimensional model-support and force-balance system, a sidewall boundary layer control system, a remote-controlled survey apparatus, and a new data acquisition system. A calibration of the mean flow parameters in the test section was conducted over the complete operational range of the tunnel. The calibration included dynamic-pressure measurements, Mach number distributions, flow-angularity measurements, boundary-layer characteristics, and total-pressure profiles. In addition, test-section turbulence measurements made after the tunnel modifications have been included with these calibration data to show a comparison of existing turbulence levels with data obtained for the facility in 1941 with the original screen installation.

Mcghee, R. J.↗
NASA NTRS1982

Low-speed aerodynamic characteristics of a 9.3-percent-thick supercritical airfoil section

An investigation was conducted in the Langley low turbulence pressure tunnel to determine the low-speed, two dimensional characteristics of a 9.3 percent-thick supercritical airfoil. The airfoil was tested at Reynolds numbers (based on chord) from 2.9 million to 16.8 million, at Mach numbers from 0.10 to 0.36, and at geometric angles of attack from -8 degrees to 14 degrees.

Noonan, K. W.↗
NASA NTRS1981

Wind-tunnel results for a modified 17-percent-thick low-speed airfoil section

Wind-tunnel tests were conducted in the Langley low-turbulence pressure tunnel to evaluate the effects on performance of modifying a 17-percent-thick low-speed airfoil. The airfoil contour was altered to reduce the pitching-moment coefficient by increasing the forward loading and to increase the climb lift-drag ratio by decreasing the aft upper surface pressure gradient. The tests were conducted over a Mach number range from 0.07 to 0.32, a chord Reynolds number range 1.0 x 10 to the 6th power to 12.0 x 10 to the 6th power, and an angle-of-attack range from about -10 deg to 20 deg.

Mcghee, R. J.↗
NASA NTRS1980

Low-speed aerodynamic characteristics of a 17-percent-thick medium speed airfoil designed for general aviation applications

Wind tunnel tests were conducted to determine the low speed two dimensional aerodynamic characteristics of a 17 percent thick medium speed airfoil (MS(1)-0317) designed for general aviation applications. The results were compared with data for the 17 percent thick low speed airfoil (LS(1)-0417) and the 13 percent thick medium speed airfoil (MS(1)-0313). Theoretical predictions of the drag rise characteristics of this airfoil are also provided. The tests were conducted in the Langley low turbulence pressure tunnel over a Mach number range from 0.10 to 0.32, a chord Reynolds number range from 2 million to 12 million, and an angle of attack range from about -8 to 20 deg.

Mcghee, R. J.↗
NASA NTRS1980

Low-speed aerodynamic characteristics of a 14-percent-thick NASA phase 2 supercritical airfoil designed for a lift coefficient of 0.7

The low speed aerodynamic characteristics of a 14 percent thick supercritical airfoil are documented. The wind tunnel test was conducted in the Low Turbulence Pressure Tunnel. The effects of varying chord Reynolds number from 2,000,000 to 18,000,000 at a Mach number of 0.15 and the effects of varying Mach number from 0.10 to 0.32 at a Reynolds number of 6,000,000 are included.

Harris, C. D.↗
NASA NTRS1979

Low-speed aerodynamic characteristics of a 13 percent thick medium speed airfoil designed for general aviation applications

Wind tunnel tests were conducted to determine the low speed, two dimensional aerodynamic characteristics of a 13percent thick medium speed airfoil designed for general aviation applications. The results were compared with data for the 13 percent thick low speed airfoil. The tests were conducted over a Mach number range from 0.10 to 0.32, a chord Reynolds number range from 2.0 x 10 to the 6th power to 12.0 x 10 to the 6th power, and an angle of attack frange from about -8 deg to 10 deg. The objective of retaining good high-lift low speed characteristics for an airfoil designed to have good medium speed cruise performance was achieved.

Mcghee, R. J.↗
NASA NTRS1979

NASA low- and medium-speed airfoil development

The status of NASA low and medium speed airfoil research is discussed. Effects of airfoil thickness-chord ratios varying from 9 percent to 21 percent on the section characteristics for a design lift coefficient of 0.40 are presented for the initial low speed family of airfoils. Also, modifications to the 17-percent low-speed airfoil to reduce the pitching-moment coefficient and to the 21-percent low speed airfoil results are shown for two new medium speed airfoils with thickness ratios of 13 percent and 17 percent and design-lift coefficients of 0.30. Applications of NASA-developed airfoils to general aviation aircraft are summarized.

Mcghee, R. J.↗
NASA NTRS1978

Low-speed aerodynamic characteristics of a 16-percent-thick variable-geometry airfoil designed for general aviation applications

Tests were conducted in the Langley low-turbulence pressure tunnel to determine the aerodynamic characteristics of climb, cruise, and landing configurations. These tests were conducted over a Mach number range from 0.10 to 0.35, a chord Reynolds number range from 2.0 x 1 million to 20.0 x 1 million, and an angle-of-attack range from -8 deg to 20 deg. Results show that the maximum section lift coefficients increased in the Reynolds number range from 2.0 x 1 million to 9.0 x 1 million and reached values of approximately 2.1, 1.8, and 1.5 for the landing, climb, and cruise configurations, respectively. Stall characteristics, although of the trailing-edge type, were abrupt. The section lift-drag ratio of the climb configuration with fixed transition near the leading edge was about 78 at a lift coefficient of 0.9, a Mach number of 0.15, and a Reynolds number of 4.0 x 1 million. Design lift coefficients of 0.9 and 0.4 for the climb and cruise configurations were obtained at the same angle of attack, about 6 deg, as intended. Good agreement was obtained between experimental results and the predictions of a viscous, attached-flow theoretical method.

Barnwell, R. W.↗
NASA NTRS1978

Wind-tunnel results for an improved 21-percent-thick low-speed airfoil section

Low speed wind tunnel tests were conducted to evaluate the effects on performance of modifying a 23 percent thick low speed airfoil. The airfoil contour was altered to reduce the upper-surface adverse pressure gradient and hence reduce boundary layer separation. The chord Reynolds number varied from about 2,000,000 to 9,000,000.

Mcghee, R. J.↗
NASA NTRS1977

Low-speed wind tunnel results for a modified 13-percent-thick airfoil

Wind-tunnel tests were conducted to evaluate the effects on performance of modifying a 13-percent-thick low-speed airfoil. The airfoil contour was altered to reduce the aft upper surface pressure gradient and hence delay boundary layer separation at typical lift coefficients for light general aviation airplanes. The tests were conducted at a Mach number of 0.15 or less over a Reynolds number range from about 1,000,000 to 9,000,000.

Mcghee, R. J.↗
NASA NTRS1976

Effects of thickness on the aerodynamic characteristics of an initial low-speed family of airfoils for general aviation applications

Wind tunnel tests were conducted to determine the effects of airfoil thickness-ratio on the low speed aerodynamic characteristics of an initial family of airfoils. The results were compared with theoretical predictions obtained from a subsonic viscous method. The tests were conducted over a Mach number range from 0.10 to 0.28. Chord Reynolds numbers varied from about 2.0 x 1 million to 9.0 x 1 million.

Mcghee, R. J.↗