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A Concise Theoretical Method for Profile-Drag Calculation; Advance Report

Description: In this report a method is presented for the calculation of the profile drag of airfoil sections. The method requlres only a knowledge of the theoretical velocity distribution and can be applied readily once this dlstribution is ascertained. Comparison of calculated and experimental drag characteristics for several airfoils shows a satisfactory agreement. Sample calculatlons are included.
Date: February 1944
Creator: Nitzberg, Gerald E.
Item Type: Refine your search to only Report
open access

The Conformal Transformation of an Airfoil Into a Straight Line and Its Application to the Inverse Problem of Airfoil Theory

Description: "A method of conformal transformation is developed that maps an airfoil into a straight line, the line being chosen as the extended chord line of the airfoil. The mapping is accomplished by operating directly with the airfoil ordinates. The absence of any preliminary transformation is found to shorten the work substantially over that of previous methods. Use is made of the superposition of solutions to obtain a rigorous counterpart of the approximate methods of thin-airfoils theory" (p. 1).
Date: December 1944
Creator: Mutterperl, William
Item Type: Refine your search to only Report
open access

Considerations of wake-excited vibratory stress in a pusher propeller

Description: Report presenting an equation based on simple blade-element theory and the assumption of a fixed wake pattern is derived and fitted to available data to show the first-order relation between the parameters of propeller operation and intensity of wake-excited periodic force acting on the blades of a pusher propeller. The derived equation indicates that the effect of power coefficient on the intensity of the wake-excited periodic force is small. Limited data also indicates that the wake-excited v… more
Date: February 1944
Creator: Corson, Blake W., Jr.
Item Type: Refine your search to only Report
open access

Continuous Use of Internal Cooling to Suppress Knock in Aircraft Engines Cruising at High Power

Description: Report presenting an investigation of the possibility of using internal cooling instead of fuel enrichment to suppress knock and to estimate the fuel savings that will result. Data from four different sources was examined and an analysis of the fuel consumption was conducted. Four different types of coolants were explored.
Date: August 1944
Creator: Bell, Arthur H.
Item Type: Refine your search to only Report
open access

Contributions to the Water Problem

Description: Technical report describing the investigation of the short-lived activities produced in oxygen compounds by irradiation with pile neutrons. The most prominent of these activities in cooling water is a beta and gamma emitting activity of about 8 second half-life. Because of its production by epicadmium neutrons it was believed to be the 8 second N16 produced in the pile by n,p on O16. The identification has been accomplished and it is established that the 8 second activity is N16. Part 2 of the… more
Date: July 3, 1944
Creator: Novey, Theodore B.
Item Type: Refine your search to only Report
open access

Cooling Characteristics of a Pratt and Whitney R-2800 Engine Installed in an NACA Short-Nose High-Inlet-Velocity Cowling

Description: An investigation was made of the cooling characteristics of a P and W R-2800 engine with NACA short-nose high inlet-velocity cowling. The internal aerodynamics of the cowling were studied for ranges of propeller-advance ratio and inlet-velocity ratio obtained by deflection of cowling flaps. Tests included variations of engine power, fuel/air ratio and cooling-air pressure drop. Engine cooling data are presented in the form of cooling correlation curves, and an example for calculation of cooling… more
Date: June 1944
Creator: Corson, Blake W. & McLellan, Charles H.
Item Type: Refine your search to only Report
open access

Correlation of flight data on limit pressure coefficients and their relation to high-speed burbling and critical tail loads

Description: Report presenting flight data, which shows that the absolute minimum or limit pressure coefficient on an airfoil is a function mainly of the Mach number for Mach numbers above about 0.3 and for usual flight values of the Reynolds number. The curve of limit pressure coefficient as a function of Mach number is established.
Date: September 1944
Creator: Rhode, Richard V.
Item Type: Refine your search to only Report
open access

Correlation of the drag characteristics of a typical pursuit airplane obtained from high-speed wind-tunnel and flight tests

Description: In order to obtain a correlation of drag data from wind-tunnel and flight tests at high Mach numbers, a typical pursuit airplane, with the propeller removed, was tested in flight at Mach numbers up to 0.755, and the results were compared with wind-tunnel tests of a 1/3-scale model of the airplane. The tests results show that the drag characteristics of the test airplane can be predicted with satisfactory accuracy from tests in the Ames 16-foot high-speed wind tunnel of the Ames Aeronautical Lab… more
Date: November 2, 1944
Creator: Nissen, James M.; Gadeberg, Burnett L. & Hamilton, William T.
Item Type: Refine your search to only Report
open access

Cowling and Cooling Tests of a Fleetwings Model 33 Airplane in Flight

Description: Report presenting an investigation of the cooling of a Franklin 6-AC-29S horizontally opposed cylinder air-cooled engine installed in a Fleetwings model 33 trainer. The cowling on the airplane did not provide satisfactory cooling, but several alterations were tested, including with cylinder baffles. Results regarding engine cooling, aerodynamics of the cowling installation, and predicted versus actual cowling performance are provided.
Date: May 1944
Creator: Ellerbrock, Herman H., Jr. & Wilson, Herbert A., Jr.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
open access

Cylinder-Head Cooling by Means of a Shield in the Exhaust Passage

Description: "Tests were run on a single-cylinder, air-cooled engine with a Wright C9GC cylinder to determine the improvement in cylinder-head cooling that can be obtained by building into the exhaust passage an insulating shield designed to protect the valve-guide boss and the exhaust-passage walls from the exhaust gas. The test results showed an appreciable improvement in cooling of the exhaust-valve-guide boss, of the guide bushing, and of the valve seat" (p. 1).
Date: June 1944
Creator: Wilsted, H. D. & Mulcahy, B. A.
Item Type: Refine your search to only Report
open access

Data on Material Properties and Panel Compressive Strength of a Plastic-Bonded Material of Glass Cloth and Canvas

Description: Results are presented of tests for determining the tensile, compressive, and bending properties of a material of plastic-bonding glass cloth and canvas layers. In addition, 10 panel specimens were tested in compression. Although the material is not satisfactory for primary structural use in aircraft when compared on a strength-weight basis with other materials in common use, there appears to be potential strength in the material that will require research for development. These points are consi… more
Date: December 1944
Creator: Zender, George W.; Schuette, Evan H. & Weinberger, Robert A.
Item Type: Refine your search to only Report
open access

Design of power-plant installations pressure-loss characteristics of duct components

Description: "A correlation of what are believed to be the most reliable data available on duct components of aircraft power-plant installations is presented. The information is given in a convenient form and is offered as an aid in designing duct systems and, subject to certain qualifications, as a guide in estimating their performance. The design and performance data include those for straight ducts; simple bends of square, circular, and elliptical cross sections; compound bends; diverging and converging … more
Date: June 1944
Creator: Henry, John R.
Item Type: Refine your search to only Report
open access

The design of the optimum hull for a large long-range flying boat

Description: Report presenting some principles for designing the optimum hull for a large long-range flying boat in order to suit the requirements of minimum drag, seaworthiness, and ability to take off and land at all operational gross weights. The principles include the use of moderate gross-load coefficients, ample forebody lengths, and deep steps and the close adherence of the form to that of a streamline body of revolution with a moderate fineness ratio.
Date: September 1944
Creator: Parkinson, John B.
Item Type: Refine your search to only Report
open access

Detail Calculations of the Estimated Shift in Stick-Fixed Neutral Point Due to the Windmilling Propeller and to the Fuselage of the Republic XF-12 Airplane

Description: "Detail calculations are presented of the shifts in stick-fixed neutral point of the Republic XF-12 airplane due to the windmilling propellers and to the fuselage. The results of these calculations differ somewhat from those previously made for this airplane by Republic Aviation Corporation personnel under the direction of Langley flight division personnel. Due to these differences the neutral point for the airplane is predicted to be 37.8 percent mean aerodynamic chord, instead of 40.8 percent… more
Date: October 16, 1944
Creator: White, M. D.
Item Type: Refine your search to only Report
open access

Determination of desirable lengths of Z- and channel-section columns for local-instability tests

Description: From Summary: "Local-instability tests of 24S-T aluminum-alloy formed Z- and channel-section columns were made in order to determine a length of test specimen that would avoid the increased strength associated with short lengths and also permit the occurrence of a convenient buckling pattern. The effect of column length on the critical compressive stress, on the average stress at maximum load, and on the number of half-waves of the buckling pattern is shown."
Date: October 1944
Creator: Heimerl, George J. & Roy, J. Albert
Item Type: Refine your search to only Report
open access

The determination of effective column length from strain measurements

Description: From Summary: "A method is presented for the experimental determination of the effective length of a column for which the end conditions are unknown by establishing the points of zero curvature from readings of strain gages distributed along the length of the column. Tests of four columns of different cross sections indicated that the proposed method gives satisfactory results even when there is considerable scatter in the strain-gage readings."
Date: June 1944
Creator: Schuette, Evan H. & Roy, J. Albert
Item Type: Refine your search to only Report
open access

Determination of Free Nitric Acid in UNH Solutions, Problem Assignment No. 208-X2A, Progress Report

Description: Technical report abstract: Since UNH is a highly dissociated compound which ionizes to NO3 and (UO2), the latter ion being very weakly basic, a solution of pure UNH is quite acid (pH about 3). It is possible to titrate to a phenolphthalein and point with standard caustic solution and obtain a figure which represents the free acid plus the NO3 from the the UNH. However, titration of the free nitric acid alone in such a solution presents quite a problem. By precipitating and removing uranium fro… more
Date: April 21, 1944
Creator: Parlour, A. K. & Hammond, C. W.
Item Type: Refine your search to only Report
open access

Determination of Iron Contamination of Used Lubricating Oil for Use in Measuring Rates of Wear in Aircraft Engines

Description: Report discusses methods of determining the iron contamination of used lubricating oil in order to study wear rates of piston rings and cylinder barrels of aircraft engines. Two methods of separating iron from used lubricating oil are presented. The results of the analyses of the oil are presented and the methods are evaluated.
Date: March 1944
Creator: Tischler, Adelbert O.
Item Type: Refine your search to only Report
open access

Determination of Jet-Boundary Corrections to Cowling-Flap-Outlet Pressures by an Electrical Analogy Method

Description: Report presenting corrections to the velocities near a cowling-flap tip in order to determine jet-boundary corrections to cowling-flap-outlet pressures. The presence of the low-energy air leaving the flap opening was taken into account by so shaping the nacelle model that its outer surface represented the stream surface leaving the flap tip. Copper was found unsatisfactory for use as electrode material.
Date: February 1944
Creator: Katzoff, S. & Finn, Robert S.
Item Type: Refine your search to only Report
open access

The Determination of Span Load Distribution at High Speeds by Use of High-Speed Wind-Tunnel Section Data

Description: Report presenting a tabular method for determining the span load distribution at high Mach numbers by utilizing high-speed airfoil section data. This method, which is also called the generalized method, is an easily applied process of successive approximations by which a general application of the lifting-line theory may be used to determine the span load distribution for wings composed of sections with arbitrary lift curves. An example is provided to show how the method is used.
Date: February 1944
Creator: Boshar, John
Item Type: Refine your search to only Report
open access

Determination of the Actual Contact Surface of a Brush Contact

Description: "The number of partial contact surfaces of a brush-ring contact is measured by means of a statistical method. The particular brush is fitted with wicks - that is, insulated and cemented cylinders of brush material, terminating in the brush surface. The number of partial contact surfaces can be computed from the length of the rest periods in which such wicks remain without current" (p. 1).
Date: August 1944
Creator: Holm, Ragnar
Item Type: Refine your search to only Report
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