Technical Report Archive & Image Library (TRAIL) - 334 Matching Results

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A systematic investigation of pressure distributions at high speeds over five representative NACA low-drag and conventional airfoil sections

Description: From Summary: "Pressure distributions determined from high-speed wind-tunnel tests are presented for five NACA airfoil sections representative of both low-drag and conventional types. Section characteristics of lift, drag, and quarter-chord pitching moment are presented along with the measured pressure distributions for the NACA 65sub2-215 (a=0.5), 66sub2-215 (a=0.6), 0015, 23015, and 4415 airfoils for Mach numbers up to approximately 0.85. A critical study is made of the airfoil pressure distr… more
Date: 1945
Creator: Graham, Donald J.; Nitzberg, Gerald E. & Olson, Robert N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tank Investigation of a Powered Dynamic Model of a Large Long-Range Flying Boat

Description: "Principles for designing the optimum hull for a large long-range flying boat to meet the requirements of seaworthiness, minimum drag, and ability to take off and land at all operational gross loads were incorporated in a 1/12-size powered dynamic model of a four-engine transport flying boat having a design gross load of 165,000 pounds. These design principles included the selection of a moderate beam loading, ample forebody length, sufficient depth of step, and close adherence to the form of a… more
Date: November 29, 1946
Creator: Parkinson, John B.; Olson, Roland E. & Haar, Marvin I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tank tests to determine the effect on planing-tail hulls of varying length, width, and plan-form taper of afterbody

Description: Tests were conducted in Langley Tank no. 2 on models of an unconventional flying-boat hull called a planing-tail hull to determine the effects on resistance of varying a number of afterbody parameters. The effects of varying length, width, and plan-form taper of the afterbody are presented. Tests were made with afterbodies of two widths, two lengths, and two tapers. In the tests the depth of step and the angle of afterbody keel were held constant.(author).
Date: January 7, 1946
Creator: Dawson, John R.; Walter, Robert C. & Hay, Elizabeth S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tensile Elastic Properties of Typical Stainless Steels and Nonferrous Metals as Affected by Plastic Deformation and by Heat Treatment

Description: A general discussion is given of the relationships between stress, strain, and permanent set. From stress-set curves are derived proof stresses based on five different percentages of permanent set. The influence of prior plastic extension on these values is illustrated and discussed. A discussion is given of the influence of work-hardening, rest interval, and internal stress on the form of the proof stress-extension curve.
Date: February 23, 1940
Creator: McAdam, D. J., Jr. & Mebs, R. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Test of single-stage axial-flow fan

Description: "A single-stage axial fan was built and tested in the shop of the propeller-research tunnel of the NACA. The fan comprised a simple 24-blade rotor having a diameter of 21 inches and a solidity of 0.86 and a set of 37 contravanes having a solidity of 1.33. The rotor was driven by a 25-horsepower motor capable of rotating at a speed of 3600 r.p.m. The fan was tested for volume, pressure, and efficiency over a range of delivery pressures and volumes for a wide range of contravane and blade-angle s… more
Date: September 22, 1941
Creator: Bell, E. Barton
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tests of Airfoils Designed to Delay the Compressibility Burble

Description: "Fundamental investigations of compressibility phenomena for airfoils have shown that serious adverse changes of aerodynamic characteristics occur as the local speed over the surface exceeds the local speed of sound. These adverse changes have been delayed to higher free-stream speeds by development of suitable airfoil shapes. The method of deriving such airfoil shapes is described, and aerodynamic data for a wide range of Mach numbers obtained from tests of these airfoils in the Langley 24-inc… more
Date: 1943
Creator: Stack, John
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tests of the NACA 0025 and 0035 Airfoils in the Full-Scale Wind Tunnel

Description: This report presents the results of an investigation conducted in the NACA full-scale wind tunnel to determine the aerodynamic characteristics of the 6 by 36-foot rectangular NACA 0025 and 0035 airfoils. The aerodynamic characteristics of the plain airfoils with rounded and square tips were determined by force tests through a complete angle-of-attack range; in addition, the profile drag was determined by the momentum method. The transition points on the airfoils were located by boundary-layer d… more
Date: 1941
Creator: Bullivant, W. Kenneth
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A theoretical analysis of the effect of time lag in an automatic stabilization system on the lateral oscillatory stability of an airplane

Description: "A method is presented for determining the effect of time lag in an automatic stabilization system on the lateral oscillatory stability of an airplane. The method is based on an analytical-graphical procedure. The critical time lag of the airplane-autopilot system is readily determined from the frequency-response analysis. The method is applied to a typical present-day airplane equipped with an automatic pilot sensitive to yawing acceleration and geared to the rudder so that rudder control is a… more
Date: October 28, 1949
Creator: Sternfield, Leonard & Gates, Ordway B., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical analysis of various thrust-augmentation cycles for turbojet engines

Description: "The results of analytical studies of tail-pipe-burning, water-injection, and bleedoff methods of thrust augmentation are presented that provide an insight into the operating characteristics of these augmentation methods and summarizes the performance that may be obtained when applied to a typical turbojet engine. A brief description of the principles of operation of each augmentation method is given, together with curves that illustrate the effects of the principal design and operating variabl… more
Date: September 2, 1949
Creator: Lundin, Bruce T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical and Experimental Analysis of Low-Drag Supersonic Inlets Having a Circular Cross Section and a Central Body at Mach Numbers 3.30, 2.75, and 2.45

Description: Contains theoretical and experimental analysis of circular inlets having a central body at Mach numbers of 3.30, 2.75, and 2.45. The inlets have been designed in order to have low drag and high pressure recovery. The pressure recoveries obtained are of the same order of magnitude as those previously obtained by inlets having very large external drag.
Date: August 13, 1948
Creator: Ferri, Antonio & Nucci, Louis M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical and experimental data for a number of NACA 6A-series airfoil sections

Description: The NACA 6a-series airfoil sections were designed to eliminate the trailing-edge cusp which is characteristic of the NACA 6a-series sections. Theoretical data are presented for NACA 6a-series basic thickness forms having the position of minimum pressure of 30, 40, and 50 percent chord and with thickness ratios varying from 6 percent to 15 percent. Also presented are data for a mean line designed to maintain straight sides on the cambered sections.
Date: 1948
Creator: Loftin, Laurence K., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical antisymmetric span loading for wings of arbitrary plan form at subsonic speeds

Description: A simplified lifting-surface theory that includes effects of compressibility and spanwise variation of section lift-curve slope is used to provide charts with which antisymmetric loading due to arbitrary antisymmetric angle of attack can be found for wings having symmetric plan forms with a constant spanwise sweep angle of the quarter-chord line. Consideration is given to the flexible wing in roll. Aerodynamic characteristics due to rolling, deflected ailerons, and sideslip of wings with dihedr… more
Date: December 22, 1949
Creator: DeYoung, John
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical characteristics in supersonic flow of two types of control surfaces on triangular wings

Description: From Summary :"Methods based on the linearized theory for supersonic flow were used to find the characteristics of two types of control surfaces on thin triangular wings. The first type, the constant-chord partial-span flap, was considered to extend either outboard from the center of the wing or inboard from the wing tip. The second type, the full-triangular-tip flap, was treated only for the case in which the Mach number component normal to the leading edge is supersonic. For each type, expres… more
Date: 1949
Creator: Tucker, Warren A. & Nelson, Robert L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical comparison of several methods of thrust augmentation for turbojet engines

Description: "A theoretical investigation of tail-pipe burning, water injection at the compressor inlet, combination tail-pipe burning plus water injection, bleedoff, and rocket-assist methods thrust augmentation for turbojet engines was made for an engine representative of those in current use. The effect of augmented liquid ratio on augmented thrust ratio and the effects of altitude and flight Mach number on the performance of various methods were determined. The additional take-off weight involved by the… more
Date: October 27, 1948
Creator: Hall, Eldon W. & Wilcox, E. Clinton
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of Hydrodynamic Impact Loads on Scalloped-Bottom Seaplanes and Comparisons With Experiment

Description: "An analytical method is presented for calculating the hydrodynamic impact loads and motions experienced by seaplane floats and hulls with scalloped (fluted) bottoms. The analysis treats vertical impact at zero trim in addition to the more general problem of the step impact of a seaplane at positive trim where the flight path is oblique to the keel and to the water surface. Also considered are the transformations required to represent impacts into waves" (p. 109).
Date: April 16, 1947
Creator: Milwitzky, Benjamin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of Longitudinal Stability of Airplane with Free Controls Including Effect of Friction in Control System

Description: "The relation between the elevator hinge-moment parameters and the control-forces for changes in forward speed and in maneuvers is shown for several values of static stability and elevator mass balance. The stability of the short-period oscillations is shown as a series of boundaries giving the limits of the stable region in terms of the elevator hinge-moment parameters. The effects of static stability, elevator moment of inertia, elevator mass unbalance, and airplane density are also considere… more
Date: December 23, 1943
Creator: Greenberg, Harry & Sternfield, Leonard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of Longitudinal Stability of Airplanes with Free Controls Including Effect of Friction in Control System

Description: "The relation between the elevator hinge moment parameters and the control forces for changes in forward speed and in maneuvers is shown for several values of static stability and elevator mass balance. The stability of the short period oscillations is shown as a series of boundaries giving the limits of the stable regions in terms of the elevator hinge moment parameters. The effects of static stability, elevator moment of inertia, elevator mass unbalance, and airplane density are also consider… more
Date: 1944
Creator: Greenberg, Harry & Sternfield, Leonard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of the Lateral Oscillations of an Airplane With Free Rudder With Special Reference to the Effect of Friction

Description: "Charts showing the variation in dynamic stability with the rudder hinge-moment characteristics are presented. A stabilizing rudder floating tendency combined with a high degree of aerodynamic balance is shown to lead to oscillations of increasing amplitude. This dynamic instability is increased by viscous-friction in the rudder control system" (p. 147).
Date: March 4, 1943
Creator: Greenberg, Harry & Sternfield, Leonard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of the Rolling Oscillations of an Airplane With Ailerons Free

Description: "An analysis is made of the stability of an airplane with ailerons free, with particular attention to the motions when the ailerons have a tendency to float against the wind. The present analysis supersedes the aileron investigation contained in NACA Technical Report no. 709. The equations of motion are first written to include yawing and sideslipping, and it is demonstrated that the principal effects of freeing the ailerons can be determined without regard to these motions" (p. 255).
Date: November 19, 1943
Creator: Cohen, Doris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of the Rolling Oscillations of an Airplane with Ailerons Free

Description: "An analysis is made of the stability of an airplane with ailerons free, with particular attention to the motions when the ailerons have a tendency to float against the wind. The present analysis supersedes the aileron investigation contained in NACA Report No. 709. The equations of motion are first written to include yawing and sideslipping, and it is demonstrated that the principal effects of freeing the ailerons can be determined without regard to these motions" (p. 1).
Date: 1944
Creator: Cohen, Doris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical lift and damping in roll at supersonic speeds of thin sweptback tapered wings with streamwise tips, subsonic leading edges, and supersonic trailing edges

Description: "On the basis of linearized supersonic-flow theory, generalized equations were derived and calculations made for the lift and damping in roll of a limited series of thin sweptback tapered wings. Results are applicable to wings with streamwise tips and for a range of supersonic speeds for which the wing is wholly contained between the Mach cones springing from the wing apex and from the trailing edge of the root section. A further limitation is that the tip Mach lines may not intersect on the wi… more
Date: February 15, 1949
Creator: Malvestuto, Frank S., Jr.; Margolis, Kenneth & Ribner, Herbert S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical lift and drag of thin triangular wings at supersonic speeds

Description: "A method is derived for calculating the lift and the drag due to lift of point-forward triangular wings and a restricted series of sweptback wings at supersonic speeds. The elementary or "supersonic sources" solution of the linearized equation of motion is used to find the potential function of a line of doublets. The flow about the triangular flat plate is then obtained by a surface distribution of these doublet lines. The lift-curve slope of triangular wings is found to be a function of the … more
Date: November 29, 1946
Creator: Brown, Clinton E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical motions of hydrofoil systems

Description: "Results are presented of an investigation that has been undertaken to develop theoretical methods of treating the motions of hydrofoil systems and to determine some of the important parameters. Variations of parameters include three distributions of area between the hydrofoils, two rates of change of downwash angle with angle of attack, three depths of immersion, two dihedral angles, two rates of change of lift with immersion, three longitudinal hydrofoil spacings, two radii of gyration in pit… more
Date: May 9, 1947
Creator: Imlay, Frederick H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Theoretical Stability Derivatives of Thin Sweptback Wings Tapered to a Point with Sweptback or Sweptforward Trailing Edges for a Limited Range of Supersonic Speeds

Description: "The stability derivatives valid for a limited range of supersonic speeds are presented for a series of sweptback wings tapered to a point with sweptback or sweptforward trailing edges. These wings were derived by modifying the trailing edge of a basic triangular wing so that it coincided with lines drawn from the wing tips to the wing axis of symmetry. The stability derivatives were formulated by using the pressure distributions previously obtained for the basic triangular wing for angle of at… more
Date: September 23, 1948
Creator: Malvestuto, Frank S., Jr. & Margolis, Kenneth
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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