Technical Report Archive & Image Library (TRAIL) - 5,448 Matching Results

Search Results

prev Results: 4465 - 4488 next
open access

Statics of Circular-Ring Stiffeners for Monocoque Fuselages

Description: "For circular-ring stiffeners in monocoque fuselages the bending moments, axial forces, and shear forces under the action of applied external forces or a moment are accurately computed by known methods. Circular-ring stiffeners with variable moments of inertia are likewise considered. In comparison with the step-by-step and partially graphical procedure, the one here described is a more accurate and at the same time a simpler method" (p. 1).
Date: February 1942
Creator: Stieda, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The resistance coefficient of commercial round wire grids

Description: From Summary: "The resistance coefficients of commercial types of round wire grids were examined for the purpose of obtaining the necessary data on supercharger test stands for throttling the inducted air to a pressure corresponding to a desired air density. The measurements of the coefficients ranged up to Reynolds numbers of 1000. In the arrangement of two grids in tandem, which was necessary in order to obtain high resistance coefficients with the solidity, that is, mesh density of grid, was… more
Date: January 1942
Creator: Eckert, B. & Pflüger, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Contribution to the ideal efficiency of screw propellers

Description: From Summary: "The stipulation of best thrust distribution is applied to the annular elements of the screw propeller with infinitely many blades in frictionless, incompressible flow and an ideal jet propulsion system derived possessing hyperbolic angular velocity distribution along the blade radius and combining the advantage of uniform thrust distribution over the section with minimum slipstream and rotation losses. This system is then compared with a propeller possessing the same angular velo… more
Date: January 1942
Creator: Hoff, Wilhelm
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Design of Propeller Blade Roots

Description: Predicated on the assumption of certain normal conditions for engine and propeller, simple expressions for the static and dynamic stresses of propeller blade roots are evolved. They, in combination with the fatigue strength diagram of the employed material, afford for each engine power one certain operating point by which the state of stress serving as a basis for the design of the root is defined. Different stress cases must be analyzed, depending on the vibration tendency of engine and use of… more
Date: January 1942
Creator: Cordes, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The temperature of unheated bodies in a high-speed gas stream

Description: From Summary: "The present report deals with temperature measurements on cylinders of 0.2 to 3 millimeters diameter in longitudinal and transverse air flow at speeds of 100 to 300 meters per second. Within the explored test range, that is, the probable laminar boundary layer region, the temperature of the cylinders in axial flow is practically independent of the speed and in good agreement with Pohlhausen's theoretical values; Whereas, in transverse flow, cylinders of certain diameter manifest … more
Date: December 1941
Creator: Eckert, E. & Weise, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Stress Analysis of Circular Frames

Description: "The stresses in circular frames of constant bending stiffnesses, as encountered in thin-wall shells, are investigated from the point of view of finite depth of sectional area of frame. The solution is carried out for four fundamental load conditions. The method is illustrated on a worked out example" (p. 1).
Date: December 1941
Creator: Fahlbusch, H. & Wegner, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Inertia of Dynamic Pressure Arrays

Description: From earlier measurements and the mathematical examples, it can be gathered that the inertia of dynamic pressure arrays can be computed with sufficient accuracy and the proper size of tubing established, provided that certain requirements are made on the inertia. A new mathematical term, the pneumatic time constant, depends only on the dimensions of the tubing and of the indicator and enables the comparison of different dynamic pressure arrays.
Date: December 1941
Creator: Weidemann, Hans
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Determination of the Bending and Buckling Effect in the Stress Analysis of Shell Structures Accessible From One Side Only

Description: "The present report describes a device for ascertaining the bending and buckling effect in stress measurements on shell structures accessible from one side only. Beginning with a discussion of the relationship between flexural strain and certain parameters, the respective errors of the test method for great or variable skin curvature within the test range are analyzed and illustrated by specimen example" (p. 1).
Date: December 1941
Creator: Dose, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Two-Dimensional Potential Flow Past a Smooth Wall With Partly Constant Curvature

Description: The speed of a two-dimensional flow potential flow past a smooth wall, which evinces a finite curvature jump at a certain point and approximates to two arcs in the surrounding area, has a vertical tangent of inflection in the critical point as a function of the arc length of the boundary curve. This report looks at a general theorem of the local character of the conformal function at the critical point as well as the case of the finite curvature jump.
Date: November 1941
Creator: v. Koppenfels, Werner
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Creep of Laminated Synthetic Resin Plastics

Description: "The long-time loading strength of a number of laminated synthetic resin plastics was ascertained and the effect of molding pressure and resin content determined. The best value was observed with a 30 to 40 percent resin content. The long-time loading strength also increases with increasing molding pressure up to 250 kg/cm(exp 2); a further rise in pressure affords no further substantial improvement" (p. 1)..
Date: November 1941
Creator: Perkuhn, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of Threaded and Serrated Holes on the Limited Time and Fatigue Strength of Flat Light-Alloy Strips

Description: "The investigation was made for the purpose of ascertaining the notch sensitivity of flat strips of light alloy with cylindrical holes under initial tension stress, with special attention to the change in notch-effect factors with the number of load cycles. Then the studies were extended to similar flat strips with pin-loaded holes (tension lugs). This report deals with fatigue tests under initial tension load on flat test specimens of 3116.5 duralumin and AZM 3510.1 electron with plain unloade… more
Date: November 1941
Creator: Bürnheim, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Researches on Direct Injection in Internal-Combustion Engines

Description: Report presenting a solution for reducing the fatigue of the Diesel engine by permitting the preservation of its components and, at the same time, raising its specific horsepower to a par with that of carburetor engines, while maintaining for the Diesel engine its perogative of burning heavy fuel under optimum economical conditions. The feeding of Diesel engines by injection pumps actuated by engine compression achieves the required high speeds of injection readily and permits rigorous control … more
Date: November 1941
Creator: Tuscher, Jean E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Statistical analysis of the time and fatigue strength of aircraft wing structures

Description: The results from stress measurements in flight operation afford data for analyzing the frequency of appearance of certain parts of the static breaking strength during a specified number of operating hours. Appropriate frequency evaluations furnish data for the prediction of the required strength under repeated stress in the wing structures of aircraft of the different stress categories for the specified number of operating hours demanded during the life of a component.
Date: October 1941
Creator: Kaul, Hans W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Contribution to the Aerodynamics of Rotating-Wing Aircraft: Part 2

Description: "The interrelations established in an earlier report (NACA-TM-921) are used to study the best assumptions for hovering and horizontal flight. The effect of the twisted and tapered blade on the rotor efficiency is analyzed and the gliding coefficient at different stages (from autogyro to helicopter) of horizontal flight compared. To the extent that model or full-scale test data are available, they are included in the comparison" (p. 1).
Date: October 1941
Creator: Sissingh, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Buckling Tests on Eccentrically Loaded Beam Columns

Description: "Formulas are obtained for computing the buckling load of rods eccentrically loaded at each end, the computation being extended in particular to the inelastic range. The test results are graphically presented on three sets of curves. Two of these, at least for the elastic range, are independent of the material tested. The third set, which is independent of the material, possesses greater clearness and is therefore used for comparing the test results with the theoretical" (p. 1).
Date: October 1941
Creator: Cassens, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Observations of the Effect of Wing Appendages and Flaps on the Spread of Separation of Flow Over the Wing

Description: "The spread of the separation of flow on three tapered wings insymmetrical and unsymmetrical flow was observed with silk tufts. By equal thickness and chord distribution the wings manifested a different form of lifting line. The principal result of the study was that the wings alone first disclosed complete breakdown of the flow at the tips, even the one with twist, but that after adding fuselage and engine nacelles, the twisted wing broke down completely first in the wing center" (p. 1).
Date: September 1941
Creator: Hartwig, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Factors Influencing the Fatigue Strength of Materials

Description: "A number of factors are considered which influence the static and fatigue strength of materials under practical operating conditions as contrasted with the relations obtaining under conditions of the usual testing procedure. Such factors are interruptions in operation, periodically fluctuating stress limits and mean stresses with periodic succession of several groups and stress states, statistical changes and succession of stress limits and mean stresses, frictional corrosion at junctures, and… more
Date: September 1941
Creator: Bollenrath, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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
open access

A Method of Estimating the Knock Rating of Hydrocarbon Fuel Blends

Description: "The usefulness of the knock ratings of pure hydrocarbon compounds would be increased if some reliable method of calculating the knock ratings of fuel blends was known. The purpose of this study was to investigate the possibility of developing a method of predicting the knock ratings of fuel blends. Two blending equations have been derived from an analysis based on certain assumptions relative to the cause of fuel knock" (p. 1).
Date: August 1, 1943
Creator: Sanders, Newell D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Pressure Recovery for Missiles with Reaction Propulsion at High Supersonic Speeds (The Efficiency of Shock Diffusers)

Description: "The problem of the intake of air is treated for a missile flying at supersonic speeds and of changing the kinetic energy of the air into pressure with the least possible losses. Calculations are carried out concerning the results which can be attained. After a discussion of several preliminary experiments, the practical solution of the problem at hand is indicated by model experiments. The results proved very satisfactory in view of the results which had been attained previously and the values… more
Date: June 1947
Creator: Oswatitsch, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Load Distribution in Bolted or Riveted Joints in Light-Alloy Structures

Description: "This report contains a theoretical discussion of the load distribution in bolted or riveted joints in light-alloy structures which is applicable not only for loads below the limit of proportionality but also for loads above this limit. The theory is developed for double and single shear joints. The methods given are illustrated by numerical examples and the values assumed for the bolt (or rivet) stiffnesses are based partly on theory and partly on known experimental values" (p. 1).
Date: April 1947
Creator: Vogt, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

DFS Dive-Control Brakes for Gliders and Airplanes and Analytical Study of the Drag of the DFS Dive-Control Brake

Description: These two reports are surveys on the progress and present state of development of dive-control flaps for gliders and airplanes. The second article describes how on the basis of wind tunnel and free-flight tests, the drag increase on brake flaps of the type DFS, can be predicted. Pressure records confirm a two-dimensional load distribution along the brake-flap surface.
Date: January 1940
Creator: Jacobs, Hans & Wanner, Adolf
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Preliminary Analysis of the Flying Qualities of the Consolidated Vultee MX-813 Delta-Wing Airplane Configuration at Transonic and Low Supersonic Speeds as Determined from Flights of Rocket-Powered Models

Description: "A preliminary analysis of the flying qualities of the Consolidated Vultee MX-813 delta-wing airplane configuration has been made based on the results obtained from the first two 1/8 scale models flown at the NACA Pilotless Aircraft Research Station, Wallop's Island, VA. The Mach number range covered in the tests was from 0.9 to 1.2. The analysis indicates adequate elevator control for trim in level flight over the speed range investigated" (p. 1).
Date: 1949
Creator: Mitcham, Grady L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Flight Investigation to Determine the Aerodynamic Characteristics of Rocket-Powered Models Representative of a Fighter-Type Airplane Configuration Incorporating an Inverse-Taper Wing and a Vee Tail

Description: From Summary: "Two rocket-powered models representative of a fighter-type airplane were investigated in flight at Mach numbers up to 1.01 and 1.07 by the Langley Pilotless Aircraft Research Division at its testing station at Wallops Island, Va. These models incorporated an inverse-taper wing and a vee tail and were flown with controls undeflected and wing and stabilizer set at 0 deg incidence. Values of lateral acceleration, normal acceleration velocity, and drag were obtained by use of telemet… more
Date: November 2, 1948
Creator: Alexander, Sidney R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen