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  Partner: UNT Libraries Government Documents Department
 Decade: 1930-1939
 Serial/Series Title: NACA Technical Reports
 Collection: Technical Report Archive and Image Library
An analysis of lateral stability in power-off flight with charts for use in design

An analysis of lateral stability in power-off flight with charts for use in design

Date: January 1, 1937
Creator: Zimmerman, Charles H
Description: The aerodynamic and mass factors governing lateral stability are discussed and formulas are given for their estimation. Relatively simple relationships between the governing factors and the resulting stability characteristics are presented. A series of charts is included with which approximate stability characteristics may be rapidly estimated. The effects of the various governing factors upon the stability characteristics are discussed in detail. It is pointed out that much additional research is necessary both to correlate stability characteristics with riding, flying, and handling qualities and to provide suitable data for accurate estimates of those characteristics of an airplane while it is in the design stage.
Contributing Partner: UNT Libraries Government Documents Department
An analysis of longitudinal stability in power-off flight with charts for use in design

An analysis of longitudinal stability in power-off flight with charts for use in design

Date: January 1, 1936
Creator: Zimmerman, Charles H
Description: This report presents a discussion of longitudinal stability in gliding flight together with a series of charts with which the stability characteristics of any airplane may be readily estimated.
Contributing Partner: UNT Libraries Government Documents Department
An analysis of the factors that determine the periodic twist of an autogiro rotor blade, with a comparison of predicted and measured results

An analysis of the factors that determine the periodic twist of an autogiro rotor blade, with a comparison of predicted and measured results

Date: January 1, 1937
Creator: Wheatley, John B
Description: Report presents an analysis of the factors that determine the periodic twist of a rotor blade under the action of the air forces on it. The results of the analysis show that the Fourier coefficients of the twist are linear expressions involving only the tip-speed ratio, the pitch setting, the inflow coefficient, the pitching-moment coefficient of the blade airfoil section, and the physical characteristics of the rotor blade and machine. The validity of the analysis was examined by using it to predict the twist of a rotor whose twist characteristics had previously been measured in flight. The agreement between the calculated and experimental results was satisfactory.
Contributing Partner: UNT Libraries Government Documents Department
An analytical and experimental study of the effect of periodic blade twist on the thrust, torque, and flapping motion of an autogiro rotor

An analytical and experimental study of the effect of periodic blade twist on the thrust, torque, and flapping motion of an autogiro rotor

Date: January 1, 1937
Creator: Wheatley, John B
Description: An analysis is made of the influence on autogiro rotor characteristics of a periodic blade twist that varies with the azimuth position of the rotor blade and the results are compared with experimental data. The analysis expresses the influence of this type of twist upon the thrust, torque, and flapping motion of the rotor. The check against experimental data shows that the periodic twist has a pronounced influence on the flapping motion and that this influence is accurately predicted by the analysis. The influence of the twist upon the thrust and torque could be demonstrated only indirectly, but its importance is indicated.
Contributing Partner: UNT Libraries Government Documents Department
Application of practical hydrodynamics to airship design

Application of practical hydrodynamics to airship design

Date: January 1, 1933
Creator: Upson, Ralph H
Description: The purpose of the first two parts of this report is to present in concise format all the formulas required for computation of the hydrodynamic forces, so that they can be easily computed for either straight or curvilinear flight. Improved approximations are also introduced having a high degree of accuracy throughout the entire range of practical proportions. The remaining two parts of the report are devoted respectively to stability and skin friction, as functions of the same hydrodynamic forces.
Contributing Partner: UNT Libraries Government Documents Department
Approximate stress analysis of multistringer beams with shear deformation of the flanges

Approximate stress analysis of multistringer beams with shear deformation of the flanges

Date: January 1, 1938
Creator: Kuhn, Paul
Description: The problem of the skin-stringer combinations used as axially loaded panels or as covers for box beams is considered from the point of view of the practical stress analyst. By a simple substitution the problem is reduced to the problem of the single-stringer structure, which has been treated in NACA Report no. 608. The method of making this substitution is essentially empirical; in order to justify it, comparisons are shown between calculations and strain-gage tests of three beams tested by the author and of one compression panel and three beams tested and reported elsewhere.
Contributing Partner: UNT Libraries Government Documents Department
Auto-ignition and combustion of diesel fuel in a constant-volume bomb

Auto-ignition and combustion of diesel fuel in a constant-volume bomb

Date: January 1, 1938
Creator: Selden, Robert F
Description: Report presents the results of a study of variations in ignition lag and combustion associated with changes in air temperature and density for a diesel fuel in a constant-volume bomb. The test results have been discussed in terms of engine performance wherever comparisons could be drawn. The most important conclusions drawn from this investigation are: the ignition lag was essentially independent of the injected fuel quantity. Extrapolation of the curves for the fuel used shows that the lag could not be greatly decreased by exceeding the compression-ignition engines. In order to obtain the best combustion and thermal efficiency, it was desirable to use the longest ignition lag consistent with a permissible rate of pressure rise.
Contributing Partner: UNT Libraries Government Documents Department
The automotive ignition coil

The automotive ignition coil

Date: January 1, 1932
Creator: Darnell, T H
Description: This report gives the results of a series of measurements on the secondary voltage induced in an ignition coil of typical construction under a variety of operating conditions. These results show that the theoretical predictions hitherto made as to the behavior of this type of apparatus are in satisfactory agreement with the observed facts. The large mass of data obtained is here published both for the use of other investigators who may wish to compare them with other theoretical predictions and for the use of automotive engineers who will here find definite experimental results showing the effect of secondary capacity and resistance on the crest voltage produced by ignition apparatus.
Contributing Partner: UNT Libraries Government Documents Department
Blower cooling of finned cylinders

Blower cooling of finned cylinders

Date: January 1, 1937
Creator: Schey, Oscar W
Description: Several electrically heated finned steel cylinders enclosed in jackets were cooled by air from a blower. The effect of the air conditions and fin dimensions on the average surface heat-transfer coefficient q and the power required to force the air around the cylinders were determined. Tests were conducted at air velocities between the fins from 10 to 130 miles per hour and at specific weights of the air varying from 0.046 to 0.074 pound per cubic foot. The fin dimensions of the cylinders covered a range in pitches from 0.057 to 0.25 inch average fin thicknesses from 0.035 to 0.04 inch, and fin widths from 0.67 to 1.22 inches.
Contributing Partner: UNT Libraries Government Documents Department
Calculated and measured pressure distributions over the midspan section of the NACA 4412 airfoil

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

Date: January 1, 1937
Creator: Pinkerton, Robert M
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 presented.
Contributing Partner: UNT Libraries Government Documents Department