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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Year: 1940
 Month: August
Analysis of cylinder-pressure-indicator diagrams showing effects of mixture strength and spark timing

Analysis of cylinder-pressure-indicator diagrams showing effects of mixture strength and spark timing

Date: August 1940
Creator: Gerrish, Harold C & Voss, Fred
Description: An investigation was made to determine the effect of mixture strength and of normal as well as optimum spark timing on the combustion, on the cylinder temperature, and on the performance characteristics of an engine. A single-cylinder test unit utilizing an air-cooled cylinder and a carburetor and operating with gasoline having an octane rating of 92 was used. The investigation covered a range of fuel-air ratios from 0.053 to 0.118. Indicator diagrams and engine-performance data were taken for each change in engine conditions. Examination of the indicator shows that for fuel-air ratios less than and greater than 0.082 the rate and the amount of effective fuel burned decreased. For a fuel-air ratio of 0.118 the combustion efficiency was only 58 percent. Advancing the spark timing increased the rate of pressure rise. This effect was more pronounced with leaner mixtures.
Contributing Partner: UNT Libraries Government Documents Department
An analysis of the stability of an airplane with free controls

An analysis of the stability of an airplane with free controls

Date: August 15, 1940
Creator: Jones, Robert T & Cohen, Doris
Description: Report presents the results of an investigation made of the essentials to the stability of an airplane with free control surfaces. Calculations are based on typical airplane characteristics with certain factors varied to cover a range of current designs. Stability charts are included to show the limiting values of the aerodynamic hinge moments and the weight hinge moments of the control surfaces for various positions of the center of gravity of the airplane and for control systems with various moments of inertia. The effects of reducing the chord and of eliminating the floating tendency of the surface, of changing the wing loading, and of decreasing the radius of gyration of the airplane are also indicated. An investigation has also been made of the nature of the motion of the airplane with controls free and of the modes of instability that may occur.
Contributing Partner: UNT Libraries Government Documents Department
Chart for critical compressive stress of flat rectangular plates

Chart for critical compressive stress of flat rectangular plates

Date: August 1, 1940
Creator: Hill, H N
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Dressing and packing turkeys for market.

Dressing and packing turkeys for market.

Date: August 1940
Creator: Heitz, Thomas William, 1892-
Description: Describes methods for processing a turkey to be sold at market.
Contributing Partner: UNT Libraries Government Documents Department
The Effects of Aerodynamic Heating on Ice Formations on Airplane Propellers

The Effects of Aerodynamic Heating on Ice Formations on Airplane Propellers

Date: August 1, 1940
Creator: Rodert, Lewis A.
Description: An investigation has been made of the effect of aerodynamic heating on propeller-blade temperatures. The blade temperature rise resulting from aerodynamic heating was measured and the relation between the resulting blade temperatures and the outer limit of the iced-over region was examined. It was found that the outermost station at which ice formed on a propeller blade was determined by the blade temperature rise resulting from the aerodynamic heating at that point.
Contributing Partner: UNT Libraries Government Documents Department
Full-Scale Tests of 4- and 6-Blade, Single- and Dual-Rotating Propellers, Special Report

Full-Scale Tests of 4- and 6-Blade, Single- and Dual-Rotating Propellers, Special Report

Date: August 1, 1940
Creator: Biermann, David & Hartman, Edwin P.
Description: Test of 10-foot diameter, 4- and 6-blade single- and dual-rotating propellers were conducted in the 20-foot propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream was investigated. The blade angles investigated ranged from 20 degrees to 65 degrees; the latter setting corresponds to airplane speeds of over 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6% more efficient than single-rotating ones; but when operating in the presence of a wing the gain was reduced about one-half. Other advantages of dual-rotating propellers were found to include greater power absorption and greater efficiency at the low V/nD operating range of high pitch propellers.
Contributing Partner: UNT Libraries Government Documents Department
Heat-transfer tests of two steel cylinder barrels with aluminum fins manufactured by factory production method

Heat-transfer tests of two steel cylinder barrels with aluminum fins manufactured by factory production method

Date: August 1, 1940
Creator: Ellerbrock, Herman H , Jr
Description: None
Contributing Partner: UNT Libraries Government Documents Department
High-speed drag tests of several fuselage shapes in combination with a wing

High-speed drag tests of several fuselage shapes in combination with a wing

Date: August 1, 1940
Creator: Draley, Eugene C
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Investigation of the boundary layer about a symmetrical airfoil in a wind tunnel of low turbulence

Investigation of the boundary layer about a symmetrical airfoil in a wind tunnel of low turbulence

Date: August 1, 1940
Creator: Von Doenhoff, Albert E
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Investigation of the Characteristics of a High-Aspect-Ratio Wing in the Langley 8-Foot High-Speed Tunnel

Investigation of the Characteristics of a High-Aspect-Ratio Wing in the Langley 8-Foot High-Speed Tunnel

Date: August 28, 1940
Creator: Whitcomb, Richard T.
Description: An investigation of the characteristics of a wing with an aspect ratio of 9.0 and an NACA 65-210 airfoil section has been made at Mach number up to 0.925. The wing tested has a taper ratio of 2.5:1.0, no twist, dihedral, or sweepback, and 20-percent - chord 37.5-percent-semispan plain ailerons. The results showed that serious changes in the normal-force characteristics occurred when the Mach number was increased above 0.74 at angles of attack between 4 deg. and 10 deg. and above 0.80 at 0 deg. angle of attack.Because of small outboard shifts in the lateral center of load, the bending moment at the root for conditions corresponding to a 3g pull-out at an altitude of 35,000 feet increased by approximately 5% when the Much number was increased beyond 0.83 the negative pitching moments for the high angles of attack increased, whereas those for the low angles of attack decreased with a resulting large increase in the negative slope of the pitching-moment curves. A large increase occurred in the values of the drag coefficients for the range of lift coefficients needed for level flight at an altitude of 35,000 feet when the Mach number was increased beyond a value of 0.80. ...
Contributing Partner: UNT Libraries Government Documents Department
The maximum delivery pressure of single-stage radial superchargers for aircraft engines

The maximum delivery pressure of single-stage radial superchargers for aircraft engines

Date: August 1, 1940
Creator: Null, W Von Der
Description: With the aid of simple considerations and test results, an attempt is made to clear up some obscure points that still exist. The considerations are restricted to those cases where it is in fact of advantage to"force" the large delivery heads required for high altitude and high supercharge with a single-stage supercharger.
Contributing Partner: UNT Libraries Government Documents Department
The oriental persimmon.

The oriental persimmon.

Date: August 1940
Creator: Gould, H. P.
Description: Describes the characteristics and varieties of oriental persimmon trees, and the steps for planting, cultivating, and maintaining their successful growth.
Contributing Partner: UNT Libraries Government Documents Department
A simple approximation method for obtaining the spanwise lift distribution

A simple approximation method for obtaining the spanwise lift distribution

Date: August 1, 1940
Creator: Schrenk, O
Description: The approximation method described makes possible lift-distribution computations in a few minutes. Comparison with an exact method shows satisfactory agreement. The method is of greater applicability than the exact method and includes also the important case of the wing with end plates.
Contributing Partner: UNT Libraries Government Documents Department
Stemming in Metal Mines. Progress Report 2

Stemming in Metal Mines. Progress Report 2

Date: August 1940
Creator: Johnson, John A.; Agnew, Wing G. & Mosier, McHenry
Description: Report issued by the U.S. Bureau of Mines on the progress made in metal-mine stemming. Different types of stemming methods and testing procedures are presented. This report includes tables, illustrations, and photographs.
Contributing Partner: UNT Libraries Government Documents Department
Transient Effects of the Wing Wake on the Horizontal Tail

Transient Effects of the Wing Wake on the Horizontal Tail

Date: August 1, 1940
Creator: Jones, Robert T & Fehlner, Leo F
Description: An investigation was made of the effect of the wing wake on the lift of the horizontal tail surfaces. In the development of expressions for this effect, the growth of wing circulation and wing wake, the time interval represented by the tail length, and the development of lift by the rail were considered. The theory has been applied to a specific case to show the magnitude of the effect to be expected. It is shown that, for motions below a certain frequency, the development of lift by the tail may be represented by a simple lag function. The lag is, however, somewhat greater than that indicated by the rail length.
Contributing Partner: UNT Libraries Government Documents Department