UNT Libraries Government Documents Department - 359 Matching Results

Search Results

prev Results: 49 - 72 next
open access

Calculated and measured pressure distributions over the midspan section of the NACA 4412 airfoil

Description: Pressures were simultaneously measured in the variable-density tunnel at 54 orifices distributed over the midspan section of 5 by 30 inch rectangular model of the NACA 4412 airfoil at 17 angles of attack ranging from -20 degrees to 30 degrees at a Reynolds number of approximately 3,000,000. Accurate data were thus obtained for studying the deviations of the results of potential-flow theory from measured results. The results of the analysis and a discussion of the experimental technique are pres… more
Date: March 25, 1936
Creator: Pinkerton, Robert M.
Item Type: Refine your search to only Report
open access

The calculation of take-off run

Description: From Summary: "A comparatively simple method of calculating length of take-off run is developed from the assumption of a linear variation in net accelerating force with air speed and it is shown that the error involved is negligible. Detailed instructions are given for application of the formula and for the calculation of all factors involved."
Date: January 1934
Creator: Diehl, Walter S.
Item Type: Refine your search to only Report
open access

Calculation of the Aerodynamic Characteristics of Tapered Wings With Partial-Span Flaps

Description: "Factors derived from wing theory are presented. By means of these factors, the angle of zero lift, the lift-curve slope, the pitching moment, the aerodynamic-center position, and the induced drag of tapered wings with partial-span flaps may be calculated. The factors are given for wings of aspect ratios 6 and 10 , of taper ratios from 0.25 to 1.00, and with flaps of various length. An example is presented of the method of application of the factors. Fair agreement with experimental results is … more
Date: January 23, 1939
Creator: Pearson, Henry A. & Anderson, Raymond F.
Item Type: Refine your search to only Report
open access

Calculation of the chordwise load distribution over airfoil sections with plain, split, or serially hinged trailing-edge flaps

Description: From Summary: "A method is presented for the rapid calculation of the incremental chordwise normal-force distribution over an airfoil section due to the deflection of a plain flap or tab, a split flap, or a serially hinged flap. This report is intended as a supplement to NACA Report no. 631, wherein a method is presented for the calculation of the chordwise normal-force distribution over an airfoil without a flap or, as it may be considered, an airfoil with flap (or flaps) neutral. The method e… more
Date: 1938
Creator: Allen, H. Julian
Item Type: Refine your search to only Report
open access

The characteristics of 78 related airfoil sections from tests in the variable-density wind tunnel

Description: An investigation of a large group of related airfoils was made in the NACA variable-density wind tunnel at a large value of the Reynolds number. The tests were made to provide data that may be directly employed for a rational choice of the most suitable airfoil section for a given application. The variation of the aerodynamic characteristics with variations in thickness and mean-line form were systematically studied. (author).
Date: December 20, 1932
Creator: Jacobs, Eastman N.; Ward, Kenneth E. & Pinkerton, Robert M.
Item Type: Refine your search to only Report
open access

The Characteristics of a Clark Y Wing Model Equipped With Several Forms of Low-Drag Fixed Slots

Description: This investigation was undertaken to develop a low-drag fixed slot for an airplane wing which would avoid the complications and maintenance difficulties of the present movable-type Handley Page slot. Tests were conducted on a series of fixed slots in an attempt to reduce the minimum drag coefficient without decreasing the maximum lift coefficient or the stalling angle of the slotted wing. The tests were made in the NACA 5-foot vertical wind tunnel on a Clark Y basic section having a 10-inch cho… more
Date: 1932
Creator: Weick, Fred E. & Wenzinger, Carl J.
Item Type: Refine your search to only Report
open access

Characteristics of Clark Y airfoils of small aspect ratios

Description: This report presents the results of a series of wind tunnel tests showing the force, moment, and autorotational characteristics of Clark Y airfoils having aspect ratios varying from 0.5 to 3. An airfoil of rectangular plan form was tested with rectangular tips, flared tips, and semicircular tips. Tests were also made on one airfoil of circular plan form and two airfoils of elliptical plan form. The tests revealed a marked delay of the stall and a decided increase in values of maximum lift coeff… more
Date: May 5, 1932
Creator: Zimmerman, C. H.
Item Type: Refine your search to only Report
open access

Characteristics of six propellers including the high-speed range

Description: This investigation is part of an extensive experimental study that has been carried out at full scale in the NACA 20-foot tunnel, the purpose of which has been to furnish information in regard to the functioning of the propeller-cowling-nacelle unit under all conditions of take-off, climbing, and normal flight. This report presents the results of tests of six propellers in the normal and high-speed flight range and also includes a study of the take-off characteristics.
Date: June 4, 1936
Creator: Theodorsen, Theodore; Stickle, George W. & Brevoort, M. J.
Item Type: Refine your search to only Report
open access

Characteristics of the NACA 23012 airfoil from tests in the full-scale and variable-density tunnels

Description: "This report gives the results of tests in the NACA full-scale and variable-density tunnels of a new wing section, the NACA 23012, which is one of the more promising of an extended series of related airfoils recently developed. The tests were made at several values of the Reynolds number between 1,000,000 and 8,000,000. The new airfoil develops a reasonably high maximum lift and a low profile drag, which results in an unusually high value of the speed-range index. In addition, the pitching-mome… more
Date: March 1, 1935
Creator: Jacobs, Eastman N. & Clay, William C.
Item Type: Refine your search to only Report
open access

Coefficients of discharge of fuel-injection nozzles for compression-ignition engines

Description: "This report presents the results of an investigation to determine the coefficients of discharge of nozzles with small, round orifices of the size used with high-speed compression-ignition engines. The injection pressures and chamber back pressures employed were comparable to those existing in compression-ignition engines during injection. The construction of the nozzles was varied to determine the effect of the nozzle design on the coefficient. Tests were also made with nozzles assembled in an… more
Date: September 11, 1930
Creator: Gelalles, A. G.
Item Type: Refine your search to only Report
open access

Collection of wind-tunnel data on commonly used wing sections

Description: This report groups in a uniform manner the aerodynamic properties of commonly used wing sections as determined from tests in various wind tunnels. The data have been collected from reports of a number of laboratories. Where necessary, transformation has been made to the absolute system of coefficients and tunnel wall interference corrections have been applied. Tables and graphs present the data in the various forms useful to the engineer in the selection of a wing section.
Date: January 1930
Creator: Louden, F. A.
Item Type: Refine your search to only Report
open access

Column Strength of Tubes Elastically Restrained Against Rotation at the Ends

Description: Report presents the results of a study made of the effects of known end restraint on commercially available round and streamline tubing of chromium-molybdenum steel, duralumin, stainless steel, and heat-treated chromium-molybdenum steel; and a more accurate method than any previously available, but still a practical method, was developed for designing compression members in riveted or welded structures, particularly aircraft. Two hundred specimens were tested as short, medium-length, and long c… more
Date: September 9, 1937
Creator: Osgood, William R.
Item Type: Refine your search to only Report
open access

The Column Strength of Two Extruded Aluminum-Alloy H-Sections

Description: "Extruded aluminum-alloy members of various cross sections are used in aircraft as compression members either singly or as stiffeners for aluminum-alloy sheet. In order to design such members, it is necessary to know their column strength or, in the case of stiffeners, the value of the double modulus, which is best obtained for practical purposes from column tests. Column tests made on two extruded h-sections are described, and column formulas and formulas for the ratio of the double modulus to… more
Date: September 30, 1938
Creator: Osgood, William R. & Holt, Marshall
Item Type: Refine your search to only Report
open access

Combustion in a Bomb With a Fuel-Injection System

Description: "Fuel injected into a spherical bomb filled with air at a desired density and temperature could be ignited with a spark a few thousandths of a second after injection, an interval comparable with the ignition lag in fuel-injection engines. The effect of several variables on the extent and rate of combustion was investigated: time intervals between injection and ignition of fuel of 0.003 to 0.06 second and one of 5 minutes; initial air temperatures of 100 degrees C. to 250 degrees C.; initial air… more
Date: August 9, 1935
Creator: Cohn, Mildred & Spencer, Robert C.
Item Type: Refine your search to only Report
open access

Combustion in a High-Speed Compression-Ignition Engine

Description: "An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur" (p. 63… more
Date: May 21, 1931
Creator: Rothrock, A. M.
Item Type: Refine your search to only Report
open access

Comparative Flight and Full-Scale Wind-Tunnel Measurements of the Maximum Lift of an Airplane

Description: "Determinations of the power-off maximum lift of a Fairchild 22 airplane were made in the NACA full-scale wind tunnel and in flight. The results from the two types of test were in satisfactory agreement. It was found that, when the airplane was rotated positively in pitch through the angle of stall at rates of the order of 0.1 degree per second, the maximum lift coefficient was considerably higher than that obtained in the standard tests, in which the forces are measured with the angles of atta… more
Date: October 26, 1937
Creator: Silverstein, Abe; Katzoff, S. & Hootman, James A.
Item Type: Refine your search to only Report
open access

Comparative flight performance with an NACA Roots supercharger and a turbocentrifugal supercharger

Description: This report presents the comparative flight results of a roots supercharger and a turbocentrifugal supercharger. The tests were conducted using a modified DH-4M2 airplane. The rate of climb and the high speed in level flight of the airplane were obtained for each supercharger from sea level to the ceiling. The unsupercharged performance with each supercharger mounted in place was also determined. The results of these tests show that the ceiling and rate of climb obtained were nearly the same fo… more
Date: February 25, 1930
Creator: Schey, Oscar W. & Young, Alfred W.
Item Type: Refine your search to only Report
open access

The Comparative Performance of Superchargers

Description: "This report presents a comparison of superchargers on the basis of the power required to compress the air at a definite rate, and on the basis of the net engine power developed at altitudes from 0 to 40,000 feet. The investigation included geared centrifugal, turbine-driven centrifugal, roots, and vane-type superchargers. It also includes a brief discussion of the mechanical limitations of each supercharger and explains how the method of control affects the power requirements" (p. 425).
Date: January 13, 1931
Creator: Schey, Oscar W.
Item Type: Refine your search to only Report
open access

A comparison between the theoretical and measured longitudinal stability characteristics of an airplane

Description: This report covers an investigation of the application of the theory of dynamic longitudinal stability, based on the assumption of small oscillations, to oscillations an airplane is likely to undergo in flight. The investigation was conducted with a small parasol monoplane for the fixed-stick condition. The period and damping of longitudinal oscillations were determined by direct measurements of oscillations in flight and also by calculation in which the factors that enter the theoretical stabi… more
Date: June 24, 1932
Creator: Soulé, Hartley A. & Wheatley, John B.
Item Type: Refine your search to only Report
open access

A comparison of fuel sprays from several types of injection nozzles

Description: This report presents the tests results of a series of tests made of the sprays from 14 fuel injection nozzles of 9 different types, the sprays being injected into air at atmospheric density and at 6 and 14 times atmospheric density. High-speed spark photographs of the sprays from each nozzle at each air density were taken at the rate of 2,000 per second, and from them were obtained the dimensions of the sprays and the rates of spray-tip penetration. The sprays were also injected against plastic… more
Date: December 4, 1934
Creator: Lee, Dana W.
Item Type: Refine your search to only Report
open access

Comparison of full-scale propellers having R.A.F.-6 and Clark Y airfoil sections

Description: In this report the efficiencies of two series of propellers having two types of blade sections are compared. Six full-scale propellers were used, three having R. A. F.-6 and three Clark Y airfoil sections with thickness/chord ratios of 0.06, 0.08, and 0.10. The propellers were tested at five pitch setting, which covered the range ordinarily used in practice. The propellers having the Clark Y sections gave the highest peak efficiency at the low pitch settings. At the high pitch settings, the pro… more
Date: October 8, 1930
Creator: Freeman, Hugh B.
Item Type: Refine your search to only Report
open access

The Compressibility Burble and the Effect of Compressibility on Pressures and Forces Acting on an Airfoil

Description: "Simultaneous air-flow photographs and pressure-distribution measurements were made of the NACA 4412 airfoil at high speeds to determine the physical nature of the compressibility burble. The tests were conducted in the NACA 24-inch high-speed wind tunnel. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations in the 5-inch-chord airfoil by means of a multiple-tube manometer. Following the general program, a few measurements of … more
Date: July 6, 1938
Creator: Stack, John; Lindsey, W. F. & Littell, Robert E.
Item Type: Refine your search to only Report
open access

Compressible Flow About Symmetrical Joukowski Profiles

Description: "The method of Poggi is employed for the determination of the effects of compressibility upon the flow past an obstacle. A general expression for the velocity increment due to compressibility is obtained. The general result holds whatever the shape of the obstacle; but, in order to obtain the complete solution, it is necessary to know a certain Fourier expansion of the square of the velocity of flow past the obstacle. An application is made to the case flow of a symmetrical Joukowski profile wi… more
Date: November 19, 1937
Creator: Kaplan, Carl
Item Type: Refine your search to only Report
open access

Computation of the two-dimensional flow in a laminar boundary layer

Description: A comparison is made of the boundary-layer flow computed by the approximate method developed by K. Pohlhausen with the exact solutions which have been published for several special cases. A modification of Pohlhausen's method has been developed which extends the range of application at the expense of some decrease in the accuracy of the approximations.
Date: May 1934
Creator: Dryden, Hugh L.
Item Type: Refine your search to only Report
Back to Top of Screen