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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Year: 1940
Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel

Date: January 1, 1940
Creator: Becker, John V
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report

Date: January 1, 1940
Creator: Becker, John V.
Description: Determinations of boundary-layer transition on the NACA 0012 and 2301 airfoils were made in the 8-foot high-speed wind tunnel over a range of Reynolds Numbers from 1,600,000 to 16,800,000. The results are of particular significance as compared with flight tests and tests in wind tunnels of appreciable turbulence because of the extremely low turbulence in the high-speed tunnel. A comparison of the results obtained on NACA 0012 airfoils of 2-foot and 5-foot chord at the same Reynolds Number permitted an evaluation of the effect of compressibility on transition. The local skin friction along the surface of the NACA 0012 airfoil was measured at a Reynolds Number of 10,000,000. For all the lift coefficient at which tests were made, transition occurred in the region of estimated laminar separation at the low Reynolds Numbers and approach the point of minimum static pressure as a forward limit at the high Reynolds Numbers. The effect of compressibility on transition was slight. None of the usual parameters describing the local conditions in the boundary layer near the transition point served as an index for locating the transition point. As a consequence of the lower turbulence in the 8-foot high-speed tunnel, the transition points occurred consistently ...
Contributing Partner: UNT Libraries Government Documents Department
Breaking and training colts.

Breaking and training colts.

Date: 1940
Creator: Stamburgh, V. G. (Vivian Guy), 1885-; Williams, J. O. (John Oscar), 1885- & Krantz, Earl B. (Earl Beach), 1893-
Description: Describes methods training horses for farm use. Includes training or control methods for driving, riding, shoeing, and throwing.
Contributing Partner: UNT Libraries Government Documents Department
Buckling tests with a spar-rib grill

Buckling tests with a spar-rib grill

Date: September 1, 1940
Creator: Weinhold, Josef
Description: The present report deals with a comparison of mathematically and experimentally defined buckling loads of a spar-rib grill, on the assumption of constant spar section, and infinitely closely spaced ribs with rigidity symmetrical to the grill center. The loads are applied as equal bending moments at both spar ends, as compression in the line connecting the joints, and in the spar center line as the assumedly uniformly distributed spar weight.
Contributing Partner: UNT Libraries Government Documents Department
Business records for poultry keepers.

Business records for poultry keepers.

Date: 1940
Creator: Johnson, E. R. (Ernest Reuben), 1892- & Lee, Alfred R., b. 1887.
Description: Describes business methods to help poultry keepers with their production and marketing issues, discusses record-keeping methods, and includes suggestions to improve efficiency of a farmer's poultry business.
Contributing Partner: UNT Libraries Government Documents Department
The calculated effect of various hydrodynamic and aerodynamic factors on the take-off of a large flying boat

The calculated effect of various hydrodynamic and aerodynamic factors on the take-off of a large flying boat

Date: January 1, 1940
Creator: Olson, R E & Allison, J M
Description: Report presents the results of an investigation made to determine the influence of various factors on the take-off performance of a hypothetical large flying boat by means of take-off calculations. The factors varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The take-off times and distances were calculated to the stalling speeds and the performance above these speeds was separately studied to determine piloting technique for optimum take-off.
Contributing Partner: UNT Libraries Government Documents Department
Care and management of farm work horses.

Care and management of farm work horses.

Date: March 1940
Creator: Williams, J. O. (John Oscar), 1885- & Krantz, Earl B. (Earl Beach), 1893-
Description: Describes how to successfully manage and care for work horses on the farm to maximize serviceability and profitability.
Contributing Partner: UNT Libraries Government Documents Department
Care and repair of mowers and binders.

Care and repair of mowers and binders.

Date: 1940
Creator: United States. Dept. of Agriculture.
Description: A guide to repairing and maintaining farm mowers and binders.
Contributing Partner: UNT Libraries Government Documents Department
Cattle-Fever Ticks and Methods of Eradication

Cattle-Fever Ticks and Methods of Eradication

Date: 1940
Creator: Ellenberger, W. P. & Chapin, Robert M.
Description: Revised edition. This bulletin discusses the cattle-fever tick and methods for controlling it. Possible methods include dipping, pasture rotation, and arsenical dips. The life history of the tick is also discussed and instructions for constructing a concrete vat are given.
Contributing Partner: UNT Libraries Government Documents Department
The cause of welding cracks in aircraft steels

The cause of welding cracks in aircraft steels

Date: October 1, 1940
Creator: Muller, J
Description: The discussion in this article refers to gas welding of thin-walled parts of up to about 3 mm thickness. It was proven that by restricting the sulphur, carbon, and phosphorous content, and by electric-furnace production of the steel, it was possible in a short time to remove this defect. Weld hardness - i.e., martensite formation and hardness of the overheated zone - has no connection with the tendency to weld-crack development. Si, Cr, Mo, or V content has no appreciable effect, while increased manganese content tends to reduce the crack susceptibility.
Contributing Partner: UNT Libraries Government Documents Department
Celery growing.

Celery growing.

Date: 1940
Creator: Beattie, W. R. (William Renwick), b. 1870.
Description: A guide to commercial celery-growing, with brief instructions for growing celery in home gardens. Includes descriptions of celery diseases and insect pests.
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
Chordwise load distribution of a simple rectangular wing

Chordwise load distribution of a simple rectangular wing

Date: December 1, 1940
Creator: Wieghardt, Karl
Description: The chordwise distribution theory was taken over from the theory of the infinite wing. Since in this work a series expansion in b/t was used, the computation converges only for large aspect ratios. In this paper a useful approximate solution will be found also for wings with large chord - i.e., small aspect ratio.
Contributing Partner: UNT Libraries Government Documents Department
Clothes moths.

Clothes moths.

Date: January 1940
Creator: Back, E. A. (Ernest Adna), 1886-
Description: Describes the life cycle and characteristics of clothes moths, and methods for their control.
Contributing Partner: UNT Libraries Government Documents Department
Coal-Mine Accidents in the United States, 1937

Coal-Mine Accidents in the United States, 1937

Date: 1940
Creator: Adams, William W.; Geyer, L. E. & Parry, M. G.
Description: Report compiled by the U.S. Bureau of Mines including statistics on fatal and non-fatal accidents in coal mines located in the United States as well as data regarding the various operations (e.g., number of miners employed and average production). The information is organized into tables for comparison and the text draws some overall conclusions in the summary.
Contributing Partner: UNT Libraries Government Documents Department
Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Date: May 1, 1940
Creator: McHugh, James G.
Description: Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the cowling was simulated by a perforated plate. The results indicated that the adjustable cowling flap and the bottom opening with adjustable flap were about equally effective on the basis of pressure drop obtainable and that both were more effective means of increasing the pressure drop through the cowling than the adjustable-length skirt. At conditions of equal cooling-air flow, the net efficiency obtained with the adjustable cowling flaps and the adjustable-length cowling skirt was about 1% greater than the net efficiency obtained with the bottom opening with adjustable flap.
Contributing Partner: UNT Libraries Government Documents Department
Consideration of auxiliary jet propulsion for assisting take-off

Consideration of auxiliary jet propulsion for assisting take-off

Date: May 1, 1940
Creator: Turner, L Richard
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Constant-pressure blowers

Constant-pressure blowers

Date: January 1, 1940
Creator: Sorensen, E
Description: The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency.
Contributing Partner: UNT Libraries Government Documents Department
Construction of chimneys and fireplaces.

Construction of chimneys and fireplaces.

Date: 1940
Creator: United States. Bureau of Agricultural Engineering.
Description: Describes the principles of chimney and fireplace construction. Provides schematics.
Contributing Partner: UNT Libraries Government Documents Department
Corn culture.

Corn culture.

Date: 1940
Creator: Richey, Frederick D. (Frederick David), b. 1884.
Description: A general guide to growing corn crops in the United States, including selection, land preparation, planting, culture, and insect and disease control.
Contributing Partner: UNT Libraries Government Documents Department
Corrections on the thermometer reading in an air stream

Corrections on the thermometer reading in an air stream

Date: October 1, 1940
Creator: Van Der Maas, H J & Wynia, S
Description: A method is described for checking a correction formula, based partly on theoretical considerations, for adiabatic compression and friction in flight tests and determining the value of the constant. It is necessary to apply a threefold correction to each thermometer reading. They are a correction for adiabatic compression, friction and for time lag.
Contributing Partner: UNT Libraries Government Documents Department
Correlation Index to Aid in Interpreting Crude-Oil Analyses

Correlation Index to Aid in Interpreting Crude-Oil Analyses

Date: 1940
Creator: Smith, Harold M.
Description: Report issued by the Bureau of Mines discussing the correlation index used for analyses of crude oils. The correlation index is presented and described in detail. This report includes tables, and illustrations.
Contributing Partner: UNT Libraries Government Documents Department
Correlation of cooling data from an air-cooled cylinder and several multicylinder engines

Correlation of cooling data from an air-cooled cylinder and several multicylinder engines

Date: January 1, 1940
Creator: Pinkel, Benjamin & Ellerbrock, Herman H , Jr
Description: The theory of engine-cylinder cooling developed in a previous report was further substantiated by data obtained on a cylinder from a Wright r-1820-g engine. Equations are presented for the average head and barrel temperatures of this cylinder as functions of the engine and the cooling conditions. These equations are utilized to calculate the variation in cylinder temperature with altitude for level flight and climb. A method is presented for correlating average head and barrel temperatures and temperatures at individual points on the head and the barrel obtained on the test stand and in flight. The method is applied to the correlation and the comparison of data obtained on a number of service engines. Data are presented showing the variation of cylinder temperature with time when the power and the cooling pressure drop are suddenly changed.
Contributing Partner: UNT Libraries Government Documents Department
Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber

Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber

Date: July 1, 1940
Creator: Rothrock, A M & Biermann, Arnold E
Description: Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained with having a hemispherical-dome combustion chamber. The five aircraft-engine fuels used have octane numbers varying from 90 to 100 plus 2 ml of tetraethyl lead per gallon. The data were obtained on a 5 1/4-inch by 4 3/4-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.0 to 8.9. The inlet-air temperature was varied from 110 to 310 F. For each set of conditions, the inlet-air pressure was increased until audible knock occurred and then reduced 2 inches of mercury before data were recorded. The results for each fuel can be correlated by plotting the calculated end-gas density factor against the calculated end-gas temperature. Measurements of spark-plugs, cutting off the switch to one spark plug lowered the electrode temperature of that plug from a value of 1,365 F to a value of 957 F. The results indicate that the surface temperatures of combustion-chamber areas which become new sources of ignition markedly increase after ignition.
Contributing Partner: UNT Libraries Government Documents Department