You limited your search to:

  Partner: UNT Libraries Government Documents Department
 Collection: Technical Report Archive and Image Library
Results 15251 - 15260 of 18,906
  |   |  
The compressive yield strength of extruded shapes of 24st aluminum alloy

The compressive yield strength of extruded shapes of 24st aluminum alloy

Date: January 1, 1941
Creator: Templin, R L; Howell, F M & Hartmann, E C
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Contributions to the Data on Theoretical Metallurgy: [Part] 9. The Entropies of Inorganic Substances. Revision (1940) of Data and Methods of Calculation

Contributions to the Data on Theoretical Metallurgy: [Part] 9. The Entropies of Inorganic Substances. Revision (1940) of Data and Methods of Calculation

Date: 1941
Creator: Kelley, K. K.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Correction of the lifting-line theory for the effect of the chord

Correction of the lifting-line theory for the effect of the chord

Date: January 1, 1941
Creator: Jones, Robert T
Description: It is shown that a simple correction for the chord of a finite wing can be deduced from the three-dimensional potential flow around an elliptic plate. When this flow is compared with the flow around a section of an endless plate, it is found that the edge velocity is reduced by the factor 1/E, where E is the ratio of the semiperimeter to the span. Applying this correction to the circulation brings the theoretical lift into closer agreement with experiments.
Contributing Partner: UNT Libraries Government Documents Department
Damping characteristics of dashpots

Damping characteristics of dashpots

Date: January 1, 1941
Creator: Peterson, John B
Description: An investigation of the damping characteristics of dashpots was carried out combining theory and experiment. Laminar flow was assumed and three equations for the steady velocity of a piston moving in a cylinder filled with liquid were derived. In the first equation, the piston was assumed coaxial in the cylinder and, in the second equation, the piston was assumed eccentric in the cylinder with an element of the piston in contact with the cylinder wall. The third equation is for a piston of circular cross section in an elliptical cylinder. Experiments showed that the piston is normally eccentric in the cylinder. The pistons tested were 1.25 and 2 inches in diameter 0.062 to 1.00 inch long, and the clearances varied from 1.36 to 5.16 x 10 to the 3rd power inch. The difference in pressure on the two sides of the piston varied from about 2 to 55 pounds per square inch. The piston velocities for each assembly were measured with damping liquids of three different viscosities. At high piston velocities, when turbulent flow exists, the observed velocities were much lower than the velocities calculated on the basis of laminar flow. Results for a wide range of Reynolds numbers are ...
Contributing Partner: UNT Libraries Government Documents Department
Design charts for cross-flow tubular intercoolers charge-across-tube type

Design charts for cross-flow tubular intercoolers charge-across-tube type

Date: January 1, 1941
Creator: Valerino, Michael F
Description: None
Contributing Partner: UNT Libraries Government Documents Department
The design of fins for air-cooled cylinders

The design of fins for air-cooled cylinders

Date: January 1, 1941
Creator: Biermann, Arnold E & Ellerbrock, Herman H , Jr
Description: An analysis was made to determine the proportions of fins made of aluminum, copper, magnesium, and steel necessary to dissipate maximum quantities of heat for different fin widths, fin weights, and air-flow conditions. The analysis also concerns the determination of the optimum fin proportions when specified limits are placed on the fin dimensions. The calculation of the heat flow in the fins is based on experimentally verified, theoretical equations. The surface heat-transfer coefficients used with this equation were taken from previously reported experiments. In addition to the presentation of fin-design information, this investigation shows that optimum fin dimensions are inappreciably affected by the differences in air flow that are obtained with different air-flow arrangements or by small changes in the length of the air-flow path.
Contributing Partner: UNT Libraries Government Documents Department
Determination of control-surface characteristics from NACA plain-flap and tab data

Determination of control-surface characteristics from NACA plain-flap and tab data

Date: January 1, 1941
Creator: Ames, Milton B & Sears, Richard I
Description: The data from previous NACA pressure-distribution investigations of plain flaps and tabs have been analyzed and are presented in this paper in a form readily applicable to the problems of control-surface design. The experimentally determined variation of aerodynamic parameters with flap chord and tab chord are given in chart form and comparisons are made with the theory. With the aid of these charts and the theoretical relationships for a thin airfoil, the aerodynamic characteristics for control surfaces of any plan form with plain flaps and tabs may be determined. A discussion of the basic equations of the thin-airfoil theory and the development of a number of additional equations that will be helpful in tail design are presented in the appendixes. The procedure for applying the data is described and a sample problem of tail design is included. The data presented and the method of application set forth in this report should provide a reasonably accurate and satisfactory means of computing the aerodynamic characteristics of control surfaces.
Contributing Partner: UNT Libraries Government Documents Department
Determination of control-surface characteristics from NACA plain-flap and tab data

Determination of control-surface characteristics from NACA plain-flap and tab data

Date: January 1, 1941
Creator: Ames, Milton B & Sears, Richard I
Description: The data from previous NACA pressure-distribution investigations of plain flaps and tabs with sealed gaps have been analyzed and are presented in this paper in a form readily applicable to the problems of control-surface design. The experimentally determined variation of aerodynamic parameters with flap chord and tab chord are given in chart form and comparisons are made with the theory. With the aid of these charts and the theoretical relationships for a thin airfoil, the aerodynamic characteristics for control surfaces of any plan form with plain flaps and tabs with sealed gaps may be determined. A discussion of the basic equations of the thin-airfoil theory and the development of a number of additional equations that will be helpful in tail design are presented in the appendixes. The procedure for applying the data is described and a sample problem of horizontal tail design is included. The data presented and the method of application set forth in this report should provide a reasonably accurate and satisfactory means of computing the aerodynamic characteristics of control surfaces.
Contributing Partner: UNT Libraries Government Documents Department
Effect of aging on mechanical properties of aluminum-alloy rivets

Effect of aging on mechanical properties of aluminum-alloy rivets

Date: January 1, 1941
Creator: Roop, Frederick C
Description: Curves and tabular data present the results of strength tests made during and after 2 1/2 years of aging on rivets and rivet wire of 3/16-inch nominal diameter. The specimens were of aluminum alloy: 24s, 17s, and a17s of the duralumin type and 53s of the magnesium-silicide type.
Contributing Partner: UNT Libraries Government Documents Department
Effect of alternately high and low repeated stresses upon the fatigue strength of 25S-T aluminum alloy

Effect of alternately high and low repeated stresses upon the fatigue strength of 25S-T aluminum alloy

Date: January 1, 1941
Creator: Stickley, G W
Description: Fatigue tests were made on one lot of 3/4 inch diameter rolled-and-drawn 25S-T aluminum-alloy rod normal in composition and tensile properties. The specimens were tested at 3500 cycles per second in a rotating-beam fatigue test machine. Tests were made for three ratios (20:1, 50:1, and 200:1) of the number of cycles applied at low stress to the number applied at high stress. In general, failure occurred when the number of cycles at either the low or the high stress approached the ordinary fatigue curve for the material, regardless of the sequence in which the stresses were applied.
Contributing Partner: UNT Libraries Government Documents Department