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Results 15251 - 15274 of 19,853
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On the plane potential flow past a symmetrical lattice of arbitrary airfoils

On the plane potential flow past a symmetrical lattice of arbitrary airfoils

Date: January 1, 1944
Creator: Garrick, I E
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Performance of blowdown turbine driven by exhaust gas of nine-cylinder radial engine

Performance of blowdown turbine driven by exhaust gas of nine-cylinder radial engine

Date: January 1, 1944
Creator: Turner, L Richard & Desmon, Leland G
Description: An investigation was made of an exhaust-gas turbine having four separate nozzle boxes each covering a 90 degree arc of the nozzle diaphragm and each connected to a pair of adjacent cylinders of a nine-cylinder radial engine. This type of turbine has been called a "blowdown" turbine because it recovers the kinetic energy developed in the exhaust stacks during the blowdown period, that is the first part of the exhaust process when the piston of the reciprocating engine is nearly stationary. The purpose of the investigation was to determine whether the blow turbine could develop appreciable power without imposing any large loss in engine power arising from restriction of the engine exhaust by the turbine.
Contributing Partner: UNT Libraries Government Documents Department
Potash Salts from Texas-New Mexico Polyhalite Deposits: Commercial Possibilities, Proposed Technology, and Pertinent Salt-Solution Equilibria

Potash Salts from Texas-New Mexico Polyhalite Deposits: Commercial Possibilities, Proposed Technology, and Pertinent Salt-Solution Equilibria

Date: 1944
Creator: Conley, John E. & Partridge, Everett P.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Preknock vibrations in a spark-ignition engine cylinder as revealed by high-speed photography

Preknock vibrations in a spark-ignition engine cylinder as revealed by high-speed photography

Date: January 1, 1944
Creator: Miller, Cearcy D & Logan, Walter O , Jr
Description: The high-speed photographic investigation of the mechanics of spark-ignition engine knock recorded in three previous reports has been extended with use of the NACA high-speed camera and combustion apparatus with a piezoelectric pressure pickup in the combustion chamber. The motion pictures of knocking combustion were taken at the rate of 40,000 frames per second. Existence of the preknock vibrations in the engine cylinder suggested in Technical Report no.727 has been definitely proved and the vibrations have been analyzed both in the high-speed motion pictures and the pressure traces. Data are also included to show that the preknock vibrations do not progressively build up to cause knock. The effect of tetraethyl lead on the preknock vibrations has been studied and results of the tests are presented. Photographs are presented which in some cases clearly show evidence of autoignition in the end zone a considerable length of time before knock occurs.
Contributing Partner: UNT Libraries Government Documents Department
Profile Measurements During Cavitation

Profile Measurements During Cavitation

Date: January 1, 1944
Creator: Walchner, O.
Description: One of the problems of modern cavitation research is the experimental determination of the wing loads on airfoils during cavitation. Such experiments were made on various airfoils with the support of the naval ministry at the Kaiser Wilhelm Institute for Flow Research at Goettingen.
Contributing Partner: UNT Libraries Government Documents Department
Quarry Accidents in the United States During the Calendar Year 1942

Quarry Accidents in the United States During the Calendar Year 1942

Date: 1944
Creator: Adams, William W. & Wrenn, Virginia E.
Description: Report published by the U.S. Bureau of Mines which is a compilation of accidents in quarries located in the United States with data regarding the number and kinds of accidents as well as information about the mining operations (e.g., number of men employed, kinds of quarries, amount of work performed, etc.).
Contributing Partner: UNT Libraries Government Documents Department
Report Submitted to the Trail Smelter Arbitral Tribunal

Report Submitted to the Trail Smelter Arbitral Tribunal

Date: 1944
Creator: Dean, R. S. & Swain, R. E.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Shear-lag tests of two box beams with corrugated covers loaded to failure

Shear-lag tests of two box beams with corrugated covers loaded to failure

Date: January 1, 1944
Creator: Chiarito, Patrick T
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Stresses at cut-outs in shear resistant webs as determined by the photoelastic method

Stresses at cut-outs in shear resistant webs as determined by the photoelastic method

Date: January 1, 1944
Creator: Ruffner, Benjamin F & Schmidt, Calvin L
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Test Unit Power Supply

Test Unit Power Supply

Date: 1944
Creator: Sands, M.
Description: Technical drawing of electronic circuits and power supplies for nuclear reactors.
Contributing Partner: UNT Libraries Government Documents Department
Tests of the Northrop MX-334 glider airplane in the NACA full-scale tunnel

Tests of the Northrop MX-334 glider airplane in the NACA full-scale tunnel

Date: January 1, 1944
Creator: Brewer, Gerald W
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Tests of Thermal-Electric De-Icing Equipment for Propellers

Tests of Thermal-Electric De-Icing Equipment for Propellers

Date: January 1, 1944
Creator: Scherrer, Richard & Rodert, Lewis A
Description: Flights were made in natural icing conditions at the NACA Ice Research Project, Minneapolis, Minn. to test several designs of thermal-electric propeller de-icing blade shoes and a hub-generator design. It was found that a minimum average unit power of 2.5 watts per square inch of blade-shoe area would protect the propeller blades at the test conditions. The most satisfactory blade shoe of the three designs tested extended to the 20-percent-chord point and to 90 percent of the blade radius. A concentration of heat in the leading-edge region of this shoe was found to reduce the power input necessary for satisfactory de-icing. A satisfactory thermal design of blade shoe and a hub generator of sufficient capacity were developed.
Contributing Partner: UNT Libraries Government Documents Department
A Theoretical Investigation of Longitudinal Stability of Airplane with Free Controls Including Effect of Friction in Control System

A Theoretical Investigation of Longitudinal Stability of Airplane with Free Controls Including Effect of Friction in Control System

Date: January 1, 1944
Creator: Greenberg, Harry & Sternfield, Leonard
Description: The relation between the elevator hinge-moment parameters and the control-forces for changes in forward speed and in maneuvers is shown for several values of static stability and elevator mass balance.
Contributing Partner: UNT Libraries Government Documents Department
A Theoretical Investigation of Longitudinal Stability of Airplanes with Free Controls Including Effect of Friction in Control System

A Theoretical Investigation of Longitudinal Stability of Airplanes with Free Controls Including Effect of Friction in Control System

Date: January 1, 1944
Creator: Greenberg, Harry & Sternfield, Leonard
Description: The relation between the elevator hinge moment parameters and the control forces for changes in forward speed and in maneuvers is shown for several values of static stability and elevator mass balance. The stability of the short period oscillations is shown as a series of boundaries giving the limits of the stable regions in terms of the elevator hinge moment parameters. The effects of static stability, elevator moment of inertia, elevator mass unbalance, and airplane density are also considered. Dynamic instability is likely to occur if there is mass unbalance of the elevator control system combined with a small restoring tendency (high aerodynamic balance). This instability can be prevented by a rearrangement of the unbalancing weights which, however, involves an increase of the amount of weight necessary. It can also be prevented by the addition of viscous friction to the elevator control system provided the airplane center of gravity is not behind a certain critical position. For high values of the density parameter, which correspond to high altitudes of flight, the addition of moderate amounts of viscous friction may be destabilizing even when the airplane is statically stable. In this case, increasing the viscous friction makes the oscillation stable again. ...
Contributing Partner: UNT Libraries Government Documents Department
A theoretical investigation of the rolling oscillations of an airplane with ailerons free

A theoretical investigation of the rolling oscillations of an airplane with ailerons free

Date: January 1, 1944
Creator: Cohen, Doris
Description: None
Contributing Partner: UNT Libraries Government Documents Department
A theoretical investigation of the rolling oscillations of an airplane with ailerons free

A theoretical investigation of the rolling oscillations of an airplane with ailerons free

Date: January 1, 1944
Creator: Cohen, Doris
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 Technical 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. If the ailerons tend to float against the wind and have a high degree of aerodynamic balance, rolling oscillations, in addition to the normal lateral oscillations, are likely to occur. On the basis of the equations including only the rolling motion and the aileron deflection, formulas derived for the stability and damping of the rolling oscillations in terms of the hinge-moment derivatives are also presented showing the oscillatory regions and stability boundaries for a fictitious airplane of conventional proportion. The effects of friction in the control system are investigated and discussed.
Contributing Partner: UNT Libraries Government Documents Department
A Theoretical Investigation of the Rolling Oscillations of an Airplane with Ailerons Free

A Theoretical Investigation of the Rolling Oscillations of an Airplane with Ailerons Free

Date: January 1, 1944
Creator: Cohen, Doris
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. If the ailerons tend to float against the wind and have a high degree of aerodynamic balance, rolling oscillations, in addition to the normal lateral oscillations, are likely to occur. On the basis of the equations including only the rolling motion and the aileron deflection, formulas are derived for the stability and damping of the rolling oscillations in terms of the hinge moment derivatives and other characteristics of the ailerons and airplane. Charts are also presented showing the oscillatory regions and stability boundaries for a fictitious airplane of conventional proportions. The effects of friction in the control system are investigated and discussed. If the ailerons tend to trail with the wind, the condition for stable variation of stick force with aileron deflection is found to ...
Contributing Partner: UNT Libraries Government Documents Department
The theory of propellers I : determination of the circulation function and the mass coefficient for dual-rotating propellers

The theory of propellers I : determination of the circulation function and the mass coefficient for dual-rotating propellers

Date: January 1, 1944
Creator: Theodorsen, Theodore
Description: Values of the circulation function have been obtained for dual-rotating propellers. Numerical values are given for four, eight, and twelve-blade dual-rotating propellers and for advance ratios from 2 to about 6. In addition, the circulation function has been determine for single-rotating propellers for the higher values of the advance ratio. The mass coefficient, another quantity of significance in propeller theory, has been introduced.
Contributing Partner: UNT Libraries Government Documents Department
The Theory of Propellers II : Method for Calculating the Axial Interference Velocity

The Theory of Propellers II : Method for Calculating the Axial Interference Velocity

Date: January 1, 1944
Creator: Theodorsen, Theodore
Description: A technical method is given for calculating the axial interference velocity of a propeller. The method involves the use of certain weight functions p, q, and f. Numerical values for the weight functions are given for two-blade, three-blade, and six-blade propellers.
Contributing Partner: UNT Libraries Government Documents Department
The Theory of Propellers III : the Slipstream Contraction with Numerical Values for Two-Blade and Four-Blade Propellers

The Theory of Propellers III : the Slipstream Contraction with Numerical Values for Two-Blade and Four-Blade Propellers

Date: January 1, 1944
Creator: Theodorsen, Theodore
Description: As the conditions of the ultimate wake are concerned both theoretically and practically, the magnitude of the slipstream contraction has been calculated. It will be noted that the contraction in a representative case is of the order of only 1 percent of the propeller diameter. In consequence, all calculations need involve only first-order effects. Curves and tables are given for the contraction coefficient of two-blade and four-blade propellers for various values of the advance ratio; the contraction coefficient is defined as the contraction in the diameter of the wake helix in terms of the wake diameter at infinity. The contour lines of the wake helix are also shown at four values of the advance ratio in comparison with the contour lines for an infinite number of blades.
Contributing Partner: UNT Libraries Government Documents Department
The theory of propellers IV : thrust, energy, and efficiency formulas for single and dual rotating propellers with ideal circulation distribution

The theory of propellers IV : thrust, energy, and efficiency formulas for single and dual rotating propellers with ideal circulation distribution

Date: January 1, 1944
Creator: Theodorsen, Theodore
Description: Simple and exact expressions are given for the efficiency of single and dual rotating propellers with ideal circulation distribution as given by the Goldstein functions for single-rotating propellers and by the new functions for dual-rotating propellers from part I of the present series. The efficiency is shown to depend primarily on a defined load factor and, to a very small extent, on an axial loss factor. Tables and charts are included for practical use of the results.
Contributing Partner: UNT Libraries Government Documents Department
The theory of propellers IV : thrust, energy, and efficiency formulas for single- and dual-rotating propellers with ideal circulation distribution

The theory of propellers IV : thrust, energy, and efficiency formulas for single- and dual-rotating propellers with ideal circulation distribution

Date: January 1, 1944
Creator: Theodorsen, Theodore
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Three Channel Mixer

Three Channel Mixer

Date: 1944
Creator: Titterton, E. W.
Description: Declassified Manhattan Project technical drawing of amplifiers and electronic circuits for nuclear reactors.
Contributing Partner: UNT Libraries Government Documents Department
United States Earthquakes, 1944

United States Earthquakes, 1944

Date: 1944
Creator: unknown
Description: Report discussing earthquake activity in the United States during 1944. The report is broken down by regions and has sections for specific earthquakes.
Contributing Partner: UNT Libraries Government Documents Department