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A simplified method for the calculation of airfoil pressure distribution

Description: From Summary: "A method is presented for the rapid calculation of the pressure distribution over an airfoil section when the normal-force distribution and the pressure distribution over the "base profile" (i.e., the profile of the same airfoil were the camber line straight and the resulting airfoil at zero angle of attack) are known. This note is intended as a supplement to N.A.C.A. Report Nos. 631 and 634 wherein methods are presented for the calculation of the normal-force distribution over p… more
Date: May 1939
Creator: Allen, H. Julian
Item Type: Refine your search to only Report
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A comparison of several tapered wings designed to avoid tip stalling

Description: From Summary: "Optimum proportions of tapered wings were investigated by a method that involved a comparison of wings designed to be aerodynamically equal. The conditions of aerodynamic equality were equality in stalling speed, in induced drag at a low speed, and in the total drag at cruising speed. After the wings were adjusted to aerodynamic equivalence, the weights of the wings were calculated as a convenient method of indicating the optimum wing. The aerodynamic characteristics were calcula… more
Date: June 1939
Creator: Anderson, Raymond F.
Item Type: Refine your search to only Report
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Resistance of transparent plastics to impact

Description: From Summary: "The problem of developing a windshield for aircraft which will withstand the effect of bird impacts during flight is a difficult one, as an estimate of the striking energy will indicate. If the average speed of the airplane is considered to be about 200 miles per hour and that of the bird about 70 miles per hour, the speed of the bird relative to the airplane may be as great as 400 feet per second. If a 4-pound bird is involved, a maximum impact energy of approximately 10,000 foo… more
Date: July 1939
Creator: Axilrod, Benjamin M. & Kline, Gordon M.
Item Type: Refine your search to only Report
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Observations in Flight of the Region of Stalled Flow Over the Blades of an Autogiro Rotor

Description: "The flow over the inner halves of the rotor blades on a Kellet YG-1B autogiro was investigated in flight by making camera records of the motion of silk streamers attached to the upper surfaces of the blades. These records were analyzed to determine the boundaries of the region within which the flow over the blade sections was stalled for various tip-speed ratios. For the sake of comparison, corresponding theoretical boundaries were obtained. Both the size of the stalled area and its rate of gr… more
Date: December 1939
Creator: Bailey, F. J., Jr. & Gustafson, F. B.
Item Type: Refine your search to only Report
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Wind-Tunnel Tests of Several Forms of Fixed Wing Slot in Combination With a Slotted Flap on an N.A.C.A. 23012 Airfoil

Description: Note presenting tests of several forms of fixed wing slot in a large-chord NACA 23012 airfoil in the closed-throat 7- by 10-foot wind tunnel. The airfoil extended completely across the test section so that two-dimensional flow was approximated. The data are presented in the form of tables of important aerodynamic characteristics for each slot tested and as curves of section lift, profile-drag, and pitching-moment coefficients.
Date: April 1939
Creator: Bamber, M. J.
Item Type: Refine your search to only Report
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Wind-tunnel investigation of effect of yaw on lateral-stability characteristics 1: four N.A.C.A. 23012 wings of various plan forms with and without dihedral

Description: Four N.A.C.A. 23012 wings were tested at several angles of yaw in the N.A.C.A. 7- by 10-foot wind tunnel. All the wings have rounded tips and, in plan form, one is rectangular and the others are tapered 3:1 with various amounts of sweep. Each wing was tested with two amounts of dihedral and with partial-span split flaps. The coefficients of lift, drag, and pitching moment are given for all the models at zero yaw. The coefficients of rolling moment, yawing moment, and side force are given for th… more
Date: April 1939
Creator: Bamber, M. J. & House, R. O.
Item Type: Refine your search to only Report
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Wind-Tunnel Investigation of Effect of Yawing on Lateral-Stability Characteristics 2: Rectangular N.A.C.A. 23012 Wing with a Circular Fuselage and a Fin

Description: Note presenting testing of an N.A.C.A. 23012 rectangular wing with rounded tips in combination with a fuselage of circular cross section at several angles of yaw in the NACA 7- by 10-foot wind tunnel. The model was tested as a high-wing, a midwing, and a low-wing monoplane; for each wing location, tests were made with two amounts of dihedral and with partial-span split flaps. Results regarding the wing and fuselage, fin and fuselage, and wing, fuselage, and fin are provided.
Date: September 1939
Creator: Bamber, M. J. & House, R. O.
Item Type: Refine your search to only Report
open access

Tank Tests to Determine the Effects of the Chine Flare of a Flying-Boat Hull N.A.C.A. Model Series 62 and 69

Description: Note presenting testing of twenty-two models of flying-boat hulls for the purpose of determining the effects on water resistance and spray of 13 variations in the transverse section of the bottom of the forebody and of three variations in the form of the afterbody. Generally, the effect of chine flare on the resistance was small, although the resistance of force with chine flare was generally less than the resistance of the form without chine flare.
Date: August 1939
Creator: Bell, Joe W. & Olson, Roland E.
Item Type: Refine your search to only Report
open access

The Frequency of Torsional Vibration of a Tapered Beam

Description: "A solution for the equation of torsional vibration of tapered beams has been found in terms of Bessel functions for beams satisfying the following conditions: (a) the cross sections along the span are similar in shape; and (b) the torsional stiffness of a section can be expressed as a power of a linear function of distance along the span. The method of applying the analysis to actual cases has been described. Charts are given from which numerical values can be immediately obtained for most cas… more
Date: March 1939
Creator: Coleman, Robert P.
Item Type: Refine your search to only Report
open access

Some fundamental considerations in regard to the use of power in landing an airplane

Description: From Summary: "This note is concerned with the effect of power on landing speed and apparent maximum lift coefficient. It is shown that when secondary effects are neglected, the maximum available increase in lift due to power is equal to the thrust being developed. If the increase in lift due to power is expressed in coefficient form, very high values may be shown under conditions which, on analysis, are found to be wholly impracticable in flight."
Date: March 1939
Creator: Diehl, Walter S.
Item Type: Refine your search to only Report
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An Experimental Investigation of the Normal Acceleration of an Airplane Model in a Gust

Description: Note presenting an investigation in the gust tunnel to determine the influence of airplane wing loading, forward velocity, wing plan form, and the fuselage on the reaction of the airplane to a known gust. Tests were made for four values of gust velocity and for two gust gradients, specifically the sharp-edge gust and a gust rising linearly to full strength in a distance of several chord lengths.
Date: May 1939
Creator: Donely, Philip
Item Type: Refine your search to only Report
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Tests in the gust tunnel of a model of the XBM-1 airplane

Description: Report presenting testing of a dynamically scaled model of a Navy XBM-1 biplane in the gust tunnel to provide data for use in determining the structure of atmospheric gusts from measurements of the motions of the full-scale airplane in rough air. Records for two flights for several gradients were evaluated to give histories of events during passage through the gust.
Date: October 1939
Creator: Donely, Philip & Shufflebarger, C. C.
Item Type: Refine your search to only Report
open access

Stress concentration around an open circular hole in a plate subjected to bending normal to the plane of the plate

Description: "An aluminum-alloy plate containing an open circular hole of diameter large compared with the thickness of the plate was subjected to bending forces normal to the plane of the plate. Deflection and strain measurements were taken for two different loads. Stress concentrations occurred at the edge of the hole and the maximum stresses were tangential to the hole at the ends of the transverse diameter. The maximum stress at the edge of the hole was 1.59 times the computed stress on the net section … more
Date: December 1939
Creator: Dumont, C.
Item Type: Refine your search to only Report
open access

Wind-Tunnel Investigation of an N.A.C.A. 23021 Airfoil With Two Arrangements of a 40-Percent-Chord Slotted Flap

Description: Note presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23021 airfoil with two arrangements of a 40-percent-chord slotted flap. The effect of slot shape, flap position, and flap deflection on the section aerodynamic characteristics was determined. Results regarding coefficients, precision, plain airfoils, and slotted-flap arrangements are provided.
Date: September 1939
Creator: Duschik, Frank
Item Type: Refine your search to only Report
open access

Physical Properties of Synthetic Resin Materials

Description: "A study was made to determine the physical properties of synthetic resins having paper, canvas, and linen reinforcements, and of laminated wood impregnated with a resin varnish. The results show that commercial resins have moduli of elasticity that are too low for structural considerations. Nevertheless, there do exist plastics that have favorable mechanical properties and, with further development, it should be possible to produce resin products that compare favorably with the light-metal all… more
Date: March 1939
Creator: Fishbein, Meyer
Item Type: Refine your search to only Report
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Comparison of Profile-Drag and Boundary-Layer Measurements Obtained in Flight and in the Full-Scale Wind Tunnel

Description: "The effect of the existing turbulence in the full scale tunnel was determined from measurements of the profile drag of an N-22 section by the momentum method under corresponding conditions in flight and the tunnel. The transition-point location on the upper surface of the air-foil was also determined from velocity surveys in the boundary layer. The measurements were made at section lift coefficients from 0.480 to 0.635 with a range of Reynolds Numbers from 4,600,000 to 3,900,000. The results s… more
Date: March 1939
Creator: Goett, Harry J. & Bicknell, Joseph
Item Type: Refine your search to only Report
open access

Combined Beam-Column Stresses of Aluminum-Alloy Channel Sections

Description: The results of a research program to obtain design data on the strength of open-channel aluminum-alloy sections subjected to combined column and beam action. The results of the tests of about 70 specimens were graphed for stresses due to axial load and stresses due to bending loading as functions of length to radius of gyration of the specimens. From these graphs a design chart was derived that is suitable for ready use.
Date: September 1939
Creator: Gottlieb, R.; Thompson, T. M. & Witt, E. C.
Item Type: Refine your search to only Report
open access

Wind-tunnel investigation of an N.A.C.A. 23012 airfoil with two arrangements of a wide-chord slotted flap

Description: "An investigation has been made in the N.A.C.A. 7- by 10-foot wind tunnel of a large-chord N.A.C.A. 23012 airfoil with several arrangements of a 40-percent-chord slotted flap to determine the section aerodynamic characteristics of the airfoil as affected by slot shape, flap location, and flap deflection. The flap positions for maximum lift, the polar for arrangements considered favorable for take-off and climb, and the complete section aerodynamic characteristics for selected optimum arrangemen… more
Date: June 1939
Creator: Harris, Thomas A.
Item Type: Refine your search to only Report
open access

A semi-graphical method for analyzing strains measured on three or four gage lines intersecting at 45 degrees

Description: Report presenting a method for analyzing strains measured on three or four gage lines intersecting at 45 degrees, which helps determine the state of stress at a point on a plane. An equation for adjustment factor and a master curve is provided, which can be memorized and easily used in the future.
Date: May 1939
Creator: Hill, H. N.
Item Type: Refine your search to only Report
open access

The Effects of Some Surface Irregularities on Wing Drag

Description: "The N.A.C.A. has conducted tests to provide more complete data than were previously available for estimating the effects of common surface irregularities on wing drag. The irregularities investigated included: brazier-head and countersunk rivets, spot welds, several types of sheet-metal joints, and surface roughness. Tests were also conducted to determine the over-all effect of manufacturing irregularities incidental to riveted aluminum alloy and to spot-welded stainless-steel construction" (p… more
Date: March 1939
Creator: Hood, Manley J.
Item Type: Refine your search to only Report
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The Effects of Surface Waviness and of Rib Stitching on Wing Drag

Description: "Surface waviness and rib stitching have been investigated as part of a series of tests to determine the effects on wing drag of common surface irregularities. The tests were made in the N.A.C.A. 8-foot high-speed wind tunnel at Reynolds Numbers up to 17,000,000. The results of the tests showed that the waviness common to airplane wings will cause no serious increase in drag unless the waviness exists on the forward part of the wing, where it may cause premature transition or premature compress… more
Date: August 1939
Creator: Hood, Manley J.
Item Type: Refine your search to only Report
open access

Tests of an N.A.C.A. 23012 Airfoil with a slotted deflector flap

Description: Section aerodynamic characteristics of a large-chord N.A.C.A. 23012 airfoil with a slotted deflector flap were obtained in the N.A.C.A. 7- by 10-foot wind tunnel. The characteristics of an N.A.C.A. slotted flap and of a simple split flap are included for comparison. The slotted deflector flap was found to have a somewhat lower maximum lift coefficient and somewhat higher drag at high lift coefficients than the N.A.C.A. slotted flap. The high drag of the open slot with the deflector flap neutral… more
Date: April 1939
Creator: House, R. O.
Item Type: Refine your search to only Report
open access

The effects of partial-span slotted flaps on the aerodynamic characteristics of a rectangular and a tapered N.A.C.A. 23012 wing

Description: An investigation was made in the N.A.C.A. 7- by 10-foot wind tunnel to determine the aerodynamic characteristics of tapered and rectangular wings with partial-span slotted flaps. Two N.A.C.A. 23012 airfoils equipped with center-section and tip-section flaps were tested. The results showed that the changes in lift and drag due to changes in flap span for both rectangular and tapered wings having partial-span slotted flaps were similar to those for corresponding wings having partial-span split or… more
Date: July 1939
Creator: House, Rufus O.
Item Type: Refine your search to only Report
open access

The Unsteady Lift of a Finite Wing

Description: Note discussing the lift of a finite wing including the calculations and constants for each step of the lift. This information is compared against the lift of an infinite wing. From Summary: "Unsteady lift function for wings of finite aspect ratio have been calculated by approximate methods involving corrections of the aerodynamic inertia and of the angle of the infinite wing. The starting lift of the finite wing is found to be only slightly less than that of the infinite wing; whereas the fina… more
Date: January 1939
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
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