UNT Libraries Government Documents Department - 423 Matching Results

Search Results

open access

The Effects of Roughness at High Reynolds Numbers on the Lift and Drag Characteristics of Three Thick Airfoils

Description: "In connection with studies of airfoils applicable to large high-speed aircraft, the effects of roughness on three 22-percent-thick airfoils were investigated. The tests were made over a range of Reynolds number from about 6 to 26 x 10(exp 6) for the airfoils smooth and with roughness strips applied to the surfaces. The results indicated that for the roughened models the scale effect was generally favorable" (p. 1).
Date: August 1944
Creator: Abbott, Frank T., Jr. & Turner, Harold R., Jr.
open access

The Theory of a Free Jet of a Compressible Gas

Description: "In the present report the theory of free turbulence propagation and the boundary layer theory are developed for a plane-parallel free stream of a compressible fluid. In constructing the theory use was made of the turbulence hypothesis by Taylor (transport of vorticity) which gives best agreement with test results for problems involving heat transfer in free jets" (p. 1).
Date: March 1944
Creator: Abramovich, G. N.
open access

Wall interference in a two-dimensional-flow wind tunnel with consideration of the effect of compressibility

Description: Report presenting tunnel-wall corrections for an airfoil of finite thickness and camber in a two-dimensional-flow wind tunnel. The theory takes account of the effects of the wake of the airfoil and of the compressibility of the fluid and is based on the assumption that the chord of the airfoil is small in comparison with the height of the tunnel. The theoretical results are compared with the small amount of low-speed experimental data available and agreement is seen to be satisfactory, even for… more
Date: December 1944
Creator: Allen, H. Julian & Vincenti, Walter G.
open access

Wall interference in a two-dimensional-flow wind tunnel, with consideration of the effect of compressibility

Description: From Summary: "Theoretical tunnel-wall corrections are derived for an airfoil of finite thickness and camber in a two-dimensional-flow wind tunnel. The theory takes account of the effects of the wake of the airfoil and of the compressibility of the fluid, and is based upon the assumption that the chord of the airfoil is small in comparison with the height of the tunnel. Consideration is given to the phenomenon of choking at high speeds and its relation to the tunnel-wall corrections. The theore… more
Date: 1944
Creator: Allen, H. Julian & Vincenti, Walter G.
open access

The Knock-Limited Performance of Several Fuels Blended With S-2 Reference Fuel

Description: Report discussing the results of testing conducted to determine the knock-limited performance of fuel blends containing 80 percent of S-2 reference fuel and 20 percent of several exploratory fuels. Butyl acetate, sec-butyl acetate, isopropyl acetate, sec-butyl alcohol, tert-butyl alcohol, isopropyl alcohol, cyclohexanol, methylcyclohexanol, isobutylcarbinol, sec-butylcarbinol, triethyl borate, and dimethylfuran were examined.
Date: November 1944
Creator: Alquist, Henry E.
open access

Trends in Surface-Ignition Temperatures

Description: Report discusses the variation of surface-ignition temperature with charge density, fuel-air ratio, and surface-ignition advance. Tests on several fuels were conducted on a supercharged CFR engine to determine surface-ignition temperature as a function of the three variables. It was concluded that surface-ignition temperature is not a satisfactory criterion for differentiating between preignition characteristics of different fuels.
Date: September 1944
Creator: Alquist, Henry E. & Male, Donald W.
open access

The Effect of Compression Ratio on Knock Limits of High-Performance Fuels in a CFR Engine 1: Blends of Triptane and 28-R Fuel

Description: Report discussing the knock-limited performance of blends of triptane and 28-R fuel in an F-4 engine at three sets of conditions and three compression ratios. The knock limits of the triptane blends were more sensitive to compression ratio than the 28-R fuel, and the sensitivities of the blends increased as the severity of other engine conditions increased.
Date: October 1944
Creator: Alquist, Henry E. & Tower, Leonard K.
open access

Knock-limited performance of blends of AN-F-28 fuel containing 2 percent aromatic amines 3

Description: Report presenting tests to investigate the effect of 2-percent additions of nine aromatic amines on the knock-limited performance of AN-N-28 (28-R) fuel. The results of the testing of antiknock effectivneess of the 27 aromatic amines obtained to date in the program are also summarized.
Date: August 1944
Creator: Alquist, Henry E. & Tower, Leonard K.
open access

Knock-Limited Performance of Blends of AN-F-28 Fuel Containing 2 Percent Aromatic Amines 4

Description: Report discussing tests on the effect of 2-percent additions of 13 aromatic amines on the knock-limited performance of 28-R fuel in a CFR engine. The amines tested gave good rich mixture response at standard F-4 operating conditions, but were sensitive to engine severity at lean fuel-air ratios.
Date: December 21, 1944
Creator: Alquist, Henry E. & Tower, Leonard K.
open access

Tests of NACA 65(216)-420 and 66(218)-420 Airfoils at High Speeds

Description: Report presenting wind tunnel tests of NACA 65(216)-420 and 66(218)-420 airfoils at speeds up to and slightly above the critical. Section coefficients of lift, drag, and pitching-moment and extensive pressure-distribution data are presented. The critical speed for these airfoils at their design life coefficient of 0.4 is shown to be about 460 miles per hour at seal level and about 415 miles per hour at 25,000 feet altitude.
Date: April 10, 1944
Creator: Anderson, Joseph L.
open access

Tests of a 0.30 scale semispan model of the Douglas XTB2D-1 airplane wing and fuselage combination in the NACA 19-foot pressure tunnel 1: full-span flap and air-brake investigation

Description: Report presenting testing in the 19-foot pressure tunnel of a scale semispan model of the XTB2D-1 airplane wing and fuselage combination. The purpose of the investigation was to determine the optimum position of the double-slotted flap, the characteristics of the full-span flaps at various deflections in their fully extended position, the effectiveness of deflecting the full-span flaps to small positive angles as a camber changing feature, the stalling characteristics of the wing, and the effec… more
Date: September 1944
Creator: Ashworth, C. Dixon; Spooner, Stanley H. & Russell, Robert T.
open access

Charts for estimation of the characteristics of a helicopter rotor in forward flight I: profile drag-lift ratio for untwisted rectangular blades

Description: Report presenting charts showing the rotor profile drag-lift ratio for a helicopter rotor operating in forward flight and having hinged rectangular untwisted blades. The charts are given for a range of power input covering glides, level flight, and moderate rates of climb. A drag curve was used for preparing the charts, and the curve is compared with experimental curves for typical airfoils.
Date: August 1944
Creator: Bailey, F. J., Jr.
open access

Simplified Truss Stability Criteria

Description: Report presenting a note in two parts regarding simplified truss stability criteria. The first part covers the development of simplified criteria for the stability of planar pin-jointed trusses against buckling in the plane of the truss. The second part constitutes a report on tests carried out to verify the validity of the criteria developed in part one.
Date: July 1944
Creator: Ballhaus, W. F. & Niles, A. S.
open access

High-Speed Aerodynamic Characteristics of a Four-Engine Bomber Airplane as Determined From Tests of a 0.075-Scale Model

Description: Report presenting tests of airplane models that included investigations to determine the longitudinal stability and control, effects of various constituent parts or their modification on longitudinal stability and control, critical speed, and distribution of wing load. Some of the changes made in attempts to improve longitudinal control and to increase critical speed included auxiliary control flaps on the lower surface of the wing, revision of the windshield, increase in dimensions of outboard… more
Date: January 1944
Creator: Barnes, Robert H.
open access

High-Speed Aerodynamic Characteristics of a Four-Engine Transport Airplane as Determined From Tests of a 0.075-Scale Model

Description: Report presenting tests made in order to determine the differences in high-speed aerodynamic characteristics between models of a four-engine transport airplane and a similar bomber airplane. The main conclusion found is that the critical Mach number of the transport model is about 0.05 less than that of the bomber model.
Date: January 1944
Creator: Barnes, Robert H.
open access

The Effect of Engine Conditions on the Lead Susceptibility of Paraffinic Fuels

Description: Report presenting an investigation made on a supercharged CFR engine to determine a method for estimating lead susceptibilities of pure or blended paraffinic fuels. As a result of these studies, a chart consisting of a series of straight lines passing through the origin was developed to represent the lead susceptibilities of pure and blended paraffinic fuels in terms of knock-limited indicated mean effective pressures and octane numbers.
Date: October 1944
Creator: Barnett, Henry C. & Imming, Harry S.
open access

Supercharged-Engine Knock Tests of Methyl Tert-Butyl Ether

Description: Report presenting data that show the knock-limited performance of methyl tert-butyl ether obtained from tests made in a 17.6-cubic-inch-displacement engine under supercharged conditions. Tests for temperature sensitivity, speed sensitivity, and lead susceptibility were made on a blend of 20 percent methyl tert-butyl ether and 80 percent S-2 reference fuel.
Date: August 1944
Creator: Barnett, Henry C. & Slough, James W., Jr.
open access

Engine and inspection tests of methyl tert-butyl ether as a component of aviation fuel

Description: Report presenting an investigation of the suitability of methyl tert-butyl ether as a component of aviation fuel from considerations of knock-limited performance tests and laboratory inspection tests. Data were obtained from testing on the 17.6 engine under supercharged conditions with fuel blends containing 10 and 20 percent methyl tert-butyl ether. Results regarding small-scale-engine data, full-scale-engine data, and inspection data are provided.
Date: August 1944
Creator: Barnett, Henry C.; Meyer, Carl L. & Jones, Anthony W.
open access

An Investigation of the Mutual Interference Effects of a Tail-Surface: Stern Propeller Installation on a Model Simulating the Douglas XB-42 Empennage

Description: Report discussing the mutual interference effects of tail surfaces and a stern propeller on a model of the XB-42.The main focus was to determine the effect of tail surface-propeller spacing upon the periodic tail surface loading coincident with propeller blade passage.
Date: November 9, 1944
Creator: Bartlett, Walter A., Jr. & Marino, Alfred A.
open access

Tensile Tests of NACA and Conventional Machine-Countersunk Flush Rivets

Description: An investigation was conducted to determine and compare the tensile strength of NACA and conventional machine-countersunk flush rivets of several rivet-head angles and varying countersunk depth. The results of the investigation are presented in the form of curves that show the variation of the tensile strength of the rivet with the ratio of the sheet thickness to the rivet diameter. For the same rivet-head angle and for a given angle of c/d, the NACA rivets developed higher tensile strength tha… more
Date: October 1944
Creator: Bartone, Leonard M. & Mandel, Merven W.
open access

Critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation

Description: An exact solution and a closely concurring approximate energy solution are given for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation. It was found that an appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling. An interaction formula in general use was shown to be decidedly conse… more
Date: November 8, 1944
Creator: Batdorf, S. B. & Houbolt, John C.
open access

The NACA Impact Basin and Water Landing Tests of a Float Model at Various Velocities and Weights

Description: "The first data obtained in the United States under the controlled testing conditions necessary for establishing relationships among the numerous parameters involved when a float having both horizontal and vertical velocity contacts a water surface are presented. The data were obtained at the NACA impact basin. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant" (… more
Date: 1944
Creator: Batterson, Sidney A.
open access

The NACA Impact Basin and Water Landing Tests of a Float Model at Various Velocities and Weights

Description: Report presenting data obtained when a float with both horizontal and vertical velocity contact on a water surface. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant.
Date: August 1944
Creator: Batterson, Sidney A.
Back to Top of Screen