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Effects of Specific Types of Surface Roughness on Boundary-Layer Transition

Description: Report presenting tests of two typical low-drag airfoils of 90-inch chord to determine the effects of surface projections, grooves, and sanding scratches on boundary-layer transition. Data were obtained for projections of various sizes and chordwise locations on both low-drag airfoils.
Date: February 1946
Creator: Loftin, Laurence K., Jr.
Partner: UNT Libraries Government Documents Department
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Flight Investigation at High Speeds of Profile Drag of Wing of a P-47d Airplane Having Production Surfaces Covered With Camouflage Paint

Description: Report presenting a flight investigation made at high speeds to determine the profile drag of a P-47D airplane wing with production surfaces covered with camouflage paint. The results indicated that a minimum profile-drag coefficient of 0.0097 was attained for lift coefficients from 0.16 to 0.25 at Mach numbers less than 0.67.
Date: March 1946
Creator: Zalovcik, John A. & Daum, Fred L.
Partner: UNT Libraries Government Documents Department
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Flight Investigation of Boundary-Layer and Profile-Drag Characteristics of Smooth Wing Sections of a P-47D Airplane

Description: Report presenting a flight investigation made of boundary-layer and profile-drag characteristics of smooth wing sections of a P-47D airplane. Measurements were made at three stations on the wing: boundary-layer measurements, pressure-distribution measurements, and wake surveys. The results indicated that a minimum profile-drag coefficient of 0.0062 for the smooth section at 63 percent semispan was obtained.
Date: October 1945
Creator: Zalovcik, John A.
Partner: UNT Libraries Government Documents Department
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Flight Investigation of Boundary-Layer Control by Suction Slots on an NACA 35-215 Low-Drag Airfoil at High Reynolds Numbers

Description: Report presenting an investigation of the effectiveness of suction slots as a means of extending the laminar boundary layer in flight at high Reynolds numbers on an NACA 35-215 airfoil. The results showed that, with a slot spacing of about 5 percent of the chord, the laminar boundary layer could be maintained to or slightly beyond 45 percent of the chord.
Date: February 1944
Creator: Zalovcik, John A.; Wetmore, J. W. & von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department
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Tests of a Heated Low-Drag Airfoil

Description: Report discusses the results of an experimental investigation into the NACA 65,2-016 heated wing. Information about the effect of heating on the drag coefficients, Reynolds numbers, and stability of the laminar boundary layer.
Date: December 1942
Creator: Frick, Charles W., Jr. & McCullough, George B.
Partner: UNT Libraries Government Documents Department
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Flight Investigation of Boundary-Layer Transition and Profile Drag of an Experimental Low-Drag Wing Installed on a Figher-Type Airplane

Description: Report presenting a boundary-layer-transition and profile-drag investigation conducted on an experimental low-drag wing installed on a P-47 airplane designated the XP-47F. Measurements were made at a section outside the propeller slipstream with smooth and with standard camouflage surfaces and on the upper surface of a section in the propeller slipstream with the surface smoothed. Results regarding the right wing section outside the slipstream and left wing section in the propeller slipstream a… more
Date: April 1945
Creator: Zalovcik, John A. & Skoog, Richard B.
Partner: UNT Libraries Government Documents Department
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A Profile-Drag Investigation in Flight on an Experimental Fighter-Type Airplane the North American XP-51

Description: Report discussing the results of an investigation of the North American XP-51 and its low-drag airfoils. Several surface conditions were tested and the profile-drag coefficients were determined. The surface that was smoothened and faired by filling and sanding had the lowest profile-drag coefficient.
Date: November 1942
Creator: Zalovcik, John A.
Partner: UNT Libraries Government Documents Department
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Investigation of the Behavior of Parallel Two-Dimensional Air Jets

Description: Report presenting an investigation made of the flow downstream from a two-dimensional grid, formed of parallel rods. The two-dimensional character of the flow was insured by end plates normal to the rods and covering the entire flow field. The nature of the flow was determined primarily by means of total-head measurements.
Date: November 1944
Creator: Corrsin, Stanley
Partner: UNT Libraries Government Documents Department
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A study of the application of data on various types of flap to the design of fighter brakes

Description: Report presenting an approximate method of applying the available data on various types of flaps in the design of fighter brakes together with several examples of its use. The computed effects of flap type, size, location, and deflection as well as the effects of altitude and initial velocities on braking characteristics are also shown in some examples using the method to determine various flap arrangements.
Date: June 1942
Creator: Purser, Paul E.
Partner: UNT Libraries Government Documents Department
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Effect of a Trailing-Edge Extension on the Characteristics of a Propeller Section

Description: Report presenting a convenient technical method to evaluate changes in the airfoil characteristics resulting from an extension of the chord at the trailing edge of a propeller blade section. The method determines the change in the angle of zero lift, the ideal angle of attack, and the difference in these angles as a function of the angle and length of the trailing-edge extension.
Date: September 1944
Creator: Theodorsen, Theodore & Stickle, George W.
Partner: UNT Libraries Government Documents Department
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Variation of peak pitching-moment coefficients for six airfoils as affected by compressibility

Description: Report presenting pressure distribution tests of six NACA 16-series propeller sections with 1-foot chords in the 8-foot high-speed tunnel to determine the compressibility effects on peak section pitching-moment coefficients. Data is presented as curves of peak section pitching-moment coefficient against Mach number, thickness ratio, and camber. The peak pitching-moment coefficients were found to occur in the regions of positive and negative stall.
Date: October 1944
Creator: Cleary, Harold E.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of control-surface characteristics 17: beveled-trailing-edge flaps of 0.20, 0.30, and 0.40 airfoil chord on an NACA 0009 airfoil

Description: Report presenting force tests in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 0009 airfoil with flaps having chord at 3 locations of the airfoil chord and three degrees of the beveled trailing edges. The results indicated that, with a smooth leading edge, the increased trailing-edge angle on the flaps with sealed gaps decreased the slope of the control-fixed lift curve and the lift effectiveness.
Date: April 1944
Creator: Lockwood, Vernard E.
Partner: UNT Libraries Government Documents Department
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Effects of Compressibility on the Maximum Lift Characteristics and Spanwise Load Distribution of a 12-Foot-Span Fighter-Type Wing of NACA 230-Series Airfoil Sections

Description: Lift characteristics and pressure distribution for a NACA 230 wing were investigated for an angle of attack range of from -10 to +24 degrees and Mach range of from 0.2 to 0.7. Maximum lift coefficient increased up to a Mach number of 0.3, decreased rapidly to a Mach number of 0.55, and then decreased moderately. At high speeds, maximum lift coefficient was reached at from 10 to 12 degrees beyond the stalling angle. In high-speed stalls, resultant load underwent a moderate shift outward.
Date: November 1945
Creator: Pearson, E. O., Jr.; Evans, A. J. & West, F. E., Jr.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of Control-Surface Characteristics 15: Various Contour Modifications of a 0.30-Airfoil-Chord Plain Flap on an NACA 66(215)-014 Airfoil

Description: Report presenting force-test measurements in two-dimensional flow made in the 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 66(215)-014 airfoil equipped with true-contour, straight-contour, and beveled-trailing-edge flaps with chords 30 percent of the airfoil chord. The results are presented in the form of aerodynamic section characteristics for several flap deflections and for a sealed and unsealed gap at the flap nose.
Date: December 1943
Creator: Purser, Paul E. & Riebe, John M.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of an NACA 23021 Airfoil With Two Sizes of Balanced Split Flaps

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of a large-chord NACA 23021 airfoil with a 15-percent-chord and a 25-percent-chord balanced split flap of Clark Y profile, to determine the aerodynamic section characteristics of the airfoil-flap combinations as affected by the size, nose location, and deflection of the flaps.
Date: February 1941
Creator: Swanson, Robert S. & Schuldenfrei, Marvin J.
Partner: UNT Libraries Government Documents Department
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Preliminary Report on the Characteristics of the N.A.C.A. 4400R Series Airfoils

Description: Report presenting tests made in the variable-density wind tunnel of airfoils of the NACA 4400 series modified by reflex at the trailing edge designed to reduce the pitching moment to the value of -0.03. The modified airfoils are designated the NACA 4400R series.
Date: March 1939
Creator: Sherman, Albert
Partner: UNT Libraries Government Documents Department
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Characteristics of Naca 4400R Series Rectangular and Tapered Airfoils, Including the Effect of Split Flaps

Description: "At the request of the Bureau of Aeronautics, Navy Department, tests were made in the variable-density wind tunnel of a tapered wing of 3-10-18 plan form and based on the NACA 4400R series sections. The wing was also tested with 0.2 chord split flaps, deflected 60 degrees, in the center of the wing and having flat span to wing span ratios of 0.3, 0.5, 0.7, and 1.0, respectively" (p. 1).
Date: January 1941
Creator: Greenberg, Harry
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of perforated split flaps for use as dive brakes on a rectangular NACA 23012 airfoil

Description: Report presenting an investigation of the aerodynamic characteristics of a rectangular NACA 23012 airfoil with single and double perforated split flaps in the NACA 7- by 10-foot wind tunnel. A large range of flap spans and deflections and a large range of spanwise and chordwise locations of the flaps were investigated. Results regarding the double split flaps, single split flaps, diving speed, and aileron control are provided.
Date: July 1941
Creator: Purser, Paul E.
Partner: UNT Libraries Government Documents Department
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Experimental verification of a simplified vee-tail theory and analysis of available data on complete models with vee tails

Description: Report presenting an analysis of available data on vee-tail surfaces. The analysis indicated that a vee tail designed to provide values of stability and control parameters equal to those provided by a conventional tail would probably provide no reduction in area unless the conventional vertical tail is in a bad canopy wake or unless the vee tail has a higher effective aspect ratio than the conventional vertical and horizontal tails.
Date: January 1945
Creator: Purser, Paul E. & Campbell, John P.
Partner: UNT Libraries Government Documents Department
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Determination of the Effect of Horizontal-Tail Flexibility on Longitudinal Control Characteristics

Description: Report presenting an iteration method for determining the longitudinal control characteristics of a flexible horizontal tail. The method permits factors such as the actual spanwise variation of elasticity and the aerodynamic induction effects due to three-dimensional flow to be accounted for to any degree of accuracy needed. An analysis is also included of the effects of horizontal-tail flexibility on the tail effectiveness, the hinge-moment characteristics, and the control-force gradients in a… more
Date: February 1945
Creator: Harmon, S. M.
Partner: UNT Libraries Government Documents Department
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Effect of Compressibility on Pressure Distribution Over an Airfoil With a Slotted Frise Aileron

Description: Pressure distribution measurements were made over an airfoil with slotted Frise aileron up to 0.76 Mach at various angles of attack and aileron defections. Section characteristics were determined from these pressure data. Results indicated loss of aileron rolling power for deflections ranging from -12 Degrees to -19 Degrees.
Date: July 1944
Creator: Luoma, Arvo A.
Partner: UNT Libraries Government Documents Department
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