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Application of the Methods of Gas Dynamics to Water Flows With Free Surface 2: Flows With Momentum Discontinuities (Hydraulic Jumps)

Description: In this paper an introduction to shock polar diagrams is given which then leads into an examination of water depths in hydraulic jumps. Energy loss during these jumps is considered along with an extended look at elementary solutions of flow. An experimental test set-up is described and the results presented.
Date: March 1940
Creator: Preiswerk, Ernst
Item Type: Refine your search to only Report
open access

An Approximate Method of Calculation of Relative Humidity Required to Prevent Frosting on Inside of Aircraft Pressure Cabin Windows, Special Report

Description: This report has been prepare in response to a request for information from an aircraft company. A typical example was selected for the presentation of an approximate method of calculation of the relative humidity required to prevent frosting on the inside of a plastic window in a pressure type cabin on a high speed airplane. The results of the study are reviewed.
Date: December 5, 1940
Creator: Jones, Alun R.
Item Type: Refine your search to only Report
open access

An Autunite Deposit in the Rosamond Hills, Kern County, California

Description: From introduction: An autunite deposit in the SW 1/4 sec. 25, T. 10 N., R. 13 W. San Bernardino meridian, was visited by F. M. Chace on May 6 and 15, 1950. The deposit is about 100 yards west of a north-south country road and is at an altitude of approximately 2,775 feet. The autunite-bearing tuffaceous sandstone strikes N. 35-40 W. and dips 20 -25 SW. It has been traced about 40 feet along the strike at the base of the outcrop and for about 20 feet up the dip. Insufficient work was done to giv… more
Date: August 1940
Creator: Chace, F. M.
Item Type: Refine your search to only Report
open access

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel

Description: Report presenting determinations of boundary-layer transition on the NACA 0012 and 23012 airfoils in the high-speed wind tunnel over a range of Reynolds numbers. For all of the lift coefficients that testing occurred at, transition occurred in the region of estimated laminar separation at low Reynolds numbers and approached the point of minimum static pressure as a forward limit at high Reynolds numbers.
Date: January 1940
Creator: Becker, John V.
Item Type: Refine your search to only Report
open access

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report

Description: Determinations of boundary-layer transition on the NACA 0012 and 2301 airfoils were made in the 8-foot high-speed wind tunnel over a range of Reynolds Numbers from 1,600,000 to 16,800,000. The results are of particular significance as compared with flight tests and tests in wind tunnels of appreciable turbulence because of the extremely low turbulence in the high-speed tunnel. A comparison of the results obtained on NACA 0012 airfoils of 2-foot and 5-foot chord at the same Reynolds Number permi… more
Date: January 1940
Creator: Becker, John V.
Item Type: Refine your search to only Report
open access

Buckling Tests With a Spar-Rib Grill

Description: "The present report deals with a comparison of mathematically and experimentally defined buckling loads of a spar-rib grill, on the assumption of constant spar section, and infinitely closely spaced ribs with rigidity symmetrical to the grill center. The loads are applied as equal bending moments at both spar ends, as compression in the line connecting the joints, and in the spar center line as the assumedly uniformly distributed spar weight" (p. 1).
Date: September 1940
Creator: Weinhold, Josef
Item Type: Refine your search to only Report
open access

The Calculated Effect of Various Hydrodynamic and Aerodynamic Factors on the Take-Off of a Large Flying Boat

Description: Report presents the results of an investigation made to determine the influence of various factors on the take-off performance of a hypothetical large flying boat by means of take-off calculations. The factors varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The take-off times and distances were calculated to the stalling speeds and the performance above these speeds was separately studied to … more
Date: April 29, 1940
Creator: Olson, R. E. & Allison, J. M.
Item Type: Refine your search to only Report
open access

The Cause of Welding Cracks in Aircraft Steels

Description: The discussion in this article refers to gas welding of thin-walled parts of up to about 3 mm thickness. It was proven that by restricting the sulphur, carbon, and phosphorous content, and by electric-furnace production of the steel, it was possible in a short time to remove this defect. Weld hardness - i.e., martensite formation and hardness of the overheated zone - has no connection with the tendency to weld-crack development. Si, Cr, Mo, or V content has no appreciable effect, while increase… more
Date: October 1940
Creator: Müller, J.
Item Type: Refine your search to only Report
open access

Chordwise Load Distribution of a Simple Rectangular Wing

Description: The chordwise distribution theory was taken over from the theory of the infinite wing. Since in this work a series expansion in b/t was used, the computation converges only for large aspect ratios. In this paper a useful approximate solution will be found also for wings with large chord - i.e., small aspect ratio.
Date: December 1940
Creator: Wieghardt, Karl
Item Type: Refine your search to only Report
open access

Coal-Mine Accidents in the United States, 1937

Description: Report compiled by the U.S. Bureau of Mines including statistics on fatal and non-fatal accidents in coal mines located in the United States as well as data regarding the various operations (e.g., number of miners employed and average production). The information is organized into tables for comparison and the text draws some overall conclusions in the summary.
Date: 1940
Creator: Adams, William W.; Geyer, L. E. & Parry, M. G.
Item Type: Refine your search to only Report
open access

Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Description: "Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the co… more
Date: May 1940
Creator: McHugh, James G.
Item Type: Refine your search to only Report
open access

Consideration of Auxiliary Jet Propulsion for Assisting Take-Off

Description: Report presenting an analysis and simple method to help solve the problem of assisting the take-off of an airplane by means of auxiliary jet propulsion by determining the jet thrust and weight of jet fuel required to provide a desired reduction in take-off distance or increase in pay load or fuel load for a fixed take-off distance. The use of previous experimental work to verify the analysis is also provided.
Date: May 1940
Creator: Turner, L. Richard
Item Type: Refine your search to only Report
open access

Constant-Pressure Blowers

Description: "The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency" (p. 1).
Date: January 1940
Creator: Sörensen, E.
Item Type: Refine your search to only Report
open access

Corrections on the Thermometer Reading in an Air Stream

Description: A method is described for checking a correction formula, based partly on theoretical considerations, for adiabatic compression and friction in flight tests and determining the value of the constant. It is necessary to apply a threefold correction to each thermometer reading. They are a correction for adiabatic compression, friction and for time lag.
Date: October 1940
Creator: Van der Maas, H. J. & Wynia, S.
Item Type: Refine your search to only Report
open access

Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber

Description: From Summary: "Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained with having a hemispherical-dome combustion chamber. The five aircraft-engine fuels used have octane numbers varying from 90 to 100 plus 2 ml of tetraethyl lead per gallon. The data were obtained on a 5 1/4-inch by 4 3/4-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.0 to 8.9. The in… more
Date: July 1940
Creator: Rothrock, A. M. & Biermann, Arnold E.
Item Type: Refine your search to only Report
open access

Creep Strength of Stabilized Wrought-Aluminum Alloys

Description: Rohn-type equipment has been mounted on rubber blocks, for the purpose of damping the vibrations of the ground and of rendering the plastic yielding of the test bars less subject to outside interferences. New equipment also included three shockproof creep-testing machines with the Martens mirror instruments for recording the strain curve of the fatigue-tested specimens.
Date: November 1940
Creator: Müller, W.
Item Type: Refine your search to only Report
open access

Cyclic stress-strain studies of metals in torsion

Description: Report presenting cyclic torsion tests made to determine the effects of varying amounts of torsional overstrain on the shape of the shearing stress-strain diagrams of aluminum alloy 17ST, mild steel, wrought iron, copper, brass, and magnesium alloy AX57S. Results regarding the tensile, compressive, and shear properties are provided.
Date: December 1940
Creator: Paul, D. A. & Moore, R. L.
Item Type: Refine your search to only Report
open access

Damping formulas and experimental values of damping in flutter models

Description: The problem of determining values of structural damping for use in flutter calculations is discussed. The concept of equivalent viscous damping is reviewed and its relation to the structural damping coefficient g introduced in NACA Technical Report No. 685 is shown. The theory of normal modes is reviewed and a number of methods are described for separating the motions associated with different modes. Equations are developed for use in evaluating the damping parameters from experimental data. Ex… more
Date: February 1940
Creator: Coleman, Robert P.
Item Type: Refine your search to only Report
open access

Design Charts Relating to the Stalling of Tapered Wings

Description: An aid in airplane design, charts have been prepared to show the effects of wing taper, thickness ratio, and Reynolds number on the spanwise location of the initial stalling point. Means of improving poor stalling characteristics resulting from certain combinations of the variables have also been considered; additional figures illustrate the influence of camber increase to the wing tips, washout, central sharp leading edges, and wing-tip slots on the stalling characteristics. Data are included … more
Date: January 18, 1940
Creator: Soulé, H. A. & Anderson, R. F.
Item Type: Refine your search to only Report
open access

The Design of Cooling Ducts With Special Reference to the Boundary Layer at the Inlet

Description: "A study has been made of underslung cooling ducts with special references to the problems presented by the boundary layer on the fuselage skin. It was found that good flow can be obtained in such ducts by (1) making the inlet opening of such size that the mean inlet velocity is about 0.6 the free-stream velocity and (2) providing vanes behind as well as ahead of the radiator. Tables to facilitate design are included, together with an example " (p. 1).
Date: December 1940
Creator: Katzoff, S.
Item Type: Refine your search to only Report
open access

Determination of ground effect from tests of a glider in towed flight

Description: Report presents the results of an investigation made to find the effect of ground on the aerodynamic characteristics of a Franklin PS-2 glider. The lift, the drag, and the angle of attack of the glider in towed flight were determined at several heights from 0.14 to 1.19 span lengths and at various speeds for each height. Two wing arrangements were tested: the plain wing, and the wing with a nearly full-span 30-percent-chord split flap deflected 45 degrees. The experimental results for the plain… more
Date: April 8, 1940
Creator: Wetmore, J. W. & Turner, L. I., Jr.
Item Type: Refine your search to only Report
open access

Determination of the Characteristics of Tapered Wings

Description: This report presents tables and charts for use in determining the characteristics of tapered wings. Theoretical factors are given from which the following characteristics of tapered wings may be found: the span lift distribution, the induced-angle-of attack distribution, the lift-curve slope, the angle of zero lift, the induced drag, the aerodynamic-center position, and the pitching moment about the aerodynamic center.
Date: 1940
Creator: Anderson, Raymond F.
Item Type: Refine your search to only Report
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