133 Matching Results

Search Results

The National Safety Competition of 1929

Description: Report issued by the U.S. Bureau of Mines on the fifth annual national safety competition. The states represented in the competition are listed. Accident-frequency rates are presented as well. This report includes tables.
Date: May 1930
Creator: Adams, William Waugh
Partner: UNT Libraries Government Documents Department

Coal-Mine Fatalities in April, 1931

Description: Report issued by the U.S. Bureau of Mines on the coal mine related deaths during the month of April, 1931. The number of fatalities and the causes are presented. This report includes tables and graphs.
Date: May 1931
Creator: Adams, William Waugh & Chenoweth, L.
Partner: UNT Libraries Government Documents Department

The Magnus Effect in Theory and in Reality

Description: A discussion of the Flettner rotor is presented from a nautical and economic viewpoint, and although it was a failure, the experimental and theoretical inventions cannot be disregarded. The following critical and experimental investigation will show the relations and applicability of the theories and practical applications. The Magnus effect is described in detail and a discussion and critical review of the Magnus effect is included.
Date: May 1930
Creator: Ahlborn, F.
Partner: UNT Libraries Government Documents Department

A simplified method for the calculation of airfoil pressure distribution

Description: From Summary: "A method is presented for the rapid calculation of the pressure distribution over an airfoil section when the normal-force distribution and the pressure distribution over the "base profile" (i.e., the profile of the same airfoil were the camber line straight and the resulting airfoil at zero angle of attack) are known. This note is intended as a supplement to N.A.C.A. Report Nos. 631 and 634 wherein methods are presented for the calculation of the normal-force distribution over plain and flapped airfoils, respectively, but not of the pressures on the individual surfaces. Base-profile pressure-coefficient distributions for the usual N.A.C.A. family of airfoils, which are also suitable for several other commonly employed airfoils, are included in tabular form. With these tabulated base-profile pressures and the computed normal-force distributions, pressure distributions adequate for most engineering purposes can be obtained."
Date: May 1939
Creator: Allen, H. Julian
Partner: UNT Libraries Government Documents Department

A Study of Transparent Plastics for use on Aircraft, Special Report

Description: "Various transparent organic plastics, including both commercially available and experimental materials, have been examined to determine their suitability for use as flexible windshields on aircraft, The properties which have been studied include light transmission, haziness, distortion, resistance to weathering, scratch and indentation hardness, impact strength, dimensional stability, resistance to water and various cleaning fluids, bursting strength at normal and low temperatures, and flammability" (p. 1).
Date: May 12, 1937
Creator: Axilrod, Benjamin M. & Kline, Gordon M.
Partner: UNT Libraries Government Documents Department

Tank Tests of a Model of the NC Flying-Boat Hull - N.A.C.A. Model 44

Description: "A 1/7.06 full-size model of the NC-type hull was tested in the N.A.C.A. tank by both the general method and the specific or free-to-trim method. The results of the tests are given in curves plotted as non dimensional coefficients and are compared with the test results of N.A.C.A. model 11-A. The NC model (N.A.C.A. model 44) shows higher resistance than model 11-A at hump speed but lower resistance at high speeds. Model 44 has a higher best trim angle at the jump and a lower maximum positive trimming moment than model 11-A. At high speeds the best trim angle and the trimming moments of the two models are approximately the same" (p. 1).
Date: May 1936
Creator: Bell, Joe W.
Partner: UNT Libraries Government Documents Department

Effect of spark-timing regularity on the knock of engine performance

Description: Tests on a high-speed single-cylinder engine are described. The regularity of the spark timing was varied by driving the timer from different engine shafts. A simple and reasonably accurate method of determining the spark timing is described. The results show that irregular spark timing may cause large errors in tests of the knocking properties of fuels. For the engine tested, it was found that a change of one crankshaft degree in spark restart was equivalent to an 0.85 inch Hg change in allowable inlet pressure.
Date: May 1938
Creator: Biermann, Arnold E.
Partner: UNT Libraries Government Documents Department

Heat transfer from cylinders having closely spaced fins

Description: The heat-transfer coefficients have been determined for five steel cylinders having fins 1.22 inches wide and the spacing between the fins ranging from 0.022 to 0.131 inch. The cylinders were tested with and without baffles in a wind tunnel; they were also tested enclosed in jackets with the cooling air supplied by a blower. A maximum heat transfer was reached at a fin space of about 0.45 inch for the cylinders tested with each of the three methods of cooling investigated. The rise in temperature of the air passing between the fins and the change in flow pattern were found to be important factors limiting the heat transfer that may be obtained by decreasing the fin space. The use of baffles for directing the air around the cylinders with closely spaced fins proved very effective in increasing the over-all heat-transfer coefficient, provided that the spacing was not appreciably less than that for maximum heat transfer.
Date: May 1937
Creator: Biermann, Arnold E.
Partner: UNT Libraries Government Documents Department

The Effect of Compressibility on Eight Full-Scale Propellers Operating in the Take-Off and Climbing Range

Description: "Tests were made of eight full-scale propellers of different shape at various tip speeds up to about 1,000 feet per second. The range of blade-angle settings investigated was from 10 degrees to 30 degrees at the 0.75 radius. The results indicate that a loss in propulsive efficiency occurred at tip speeds from 0.5 to 0.7 the velocity of sound for the take-off and climbing conditions" (p. 517).
Date: May 18, 1938
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department

Engineering Study of the Seminole Area, Seminole and Pottawatomie Counties, Oklahoma

Description: Report issued by the Bureau of Mines over engineering studies conducted on Oklahoma oil fields. The results of the studies are presented and discussed. This report includes tables, illustrations, and photographs.
Date: May 1930
Creator: Brandenthaler, R. R.; Morris, W. S. & Bopp, C. R.
Partner: UNT Libraries Government Documents Department

Radiator Design and Installation

Description: "The fundamental principles of fluid flow, pressure losses, and heat transfer have been presented and analyzed for the case of a smooth tube with fully developed turbulent flow. These equations apply to tubes with large length-diameter ratios where the flow is at a high Reynolds Number. The error introduced by using these equations increases as the magnitude of the tube length and the air-flow Reynolds Number approaches the values encountered in modern radiator designs" (p. 1).
Date: May 1939
Creator: Brevoort, M. J. & Leifer, M.
Partner: UNT Libraries Government Documents Department

The effect of air-passage length on the optimum fin spacing for maximum cooling

Description: The effect on cooling of baffle length with optimum cylinder finning is discussed. Results from tests of several streamlined cylinders are given. It is shown that by employing several baffles the cooling can be increased several times.
Date: May 1938
Creator: Brevoort, Maurice J.
Partner: UNT Libraries Government Documents Department

Improved airplane windshields to provide vision in stormy weather

Description: This report presents the results of wind tunnel tests to determine possible improvements in the design of airplane windshields, particularly with respect to the pilot's vision from the cabin in stormy weather.
Date: May 23, 1934
Creator: Clay, William C.
Partner: UNT Libraries Government Documents Department

Manganese: Its Occurrence, Milling, and Metallurgy; Part 1

Description: Report issued by the U.S. Bureau of Mines discussing the "occurrence, milling, and metallurgy of manganese in the United States" (p. 1). Different properties and compounds of manganese are also discussed. This report includes a map, tables, illustrations, and photographs.
Date: May 1934
Creator: Dean, Reginald S.; DeVaney, Fred D. & Coghill, Will H.
Partner: UNT Libraries Government Documents Department

Full-scale drag tests of landing lamps

Description: "Drag tests were conducted in the N.A.C.A. full-scale wind tunnel on full-scale models of two Army Air Corps type A-6 landing lamps mounted on an 8 by 48 foot airfoil. Drag measurements were made with the lamps in the leading edge and attached to the lower surface at the 5 and 10 percent chord positions. The drag of the lamps when faired into the airfoil was also measured. The results show that at 100 miles per hour and at the angle of minimum drag of the airfoil the unaired lamps in the leading edge produced an increase in drag of 5.5 pounds and that the unaired lamps on the lower surface at either position increased the airfoil drag 22.5 pounds" (p. 1).
Date: May 1934
Creator: Dearborn, C. H.
Partner: UNT Libraries Government Documents Department

Maneuverability investigation of the F6C-3 airplane with special flight instruments

Description: "This investigation was made for the purpose of obtaining information on the maneuverability of the F6C-3 airplane. It is the first of a series of similar investigations to be conducted on a number of military airplanes for the purpose of comparing the abilities of these airplanes to maneuver, and also to establish a fund of quantitative data which may be used in formulating standards of comparison for rating the maneuverability of any airplane. A large part of this initial investigation was necessarily devoted to the development and trial of methods suitable for use in subsequent investigations of this nature" (p. 117).
Date: May 23, 1930
Creator: Dearborn, C. H. & Kirschbaum, H. W.
Partner: UNT Libraries Government Documents Department

The Effect of Rivet Heads on the Characteristics of a 6 by 36 Foot Clark Y Metal Airfoil

Description: "An investigation was conducted in the N.A.C.A. full-scale wind tunnel to determine the effects of exposed rivet heads on the aerodynamic characteristics of a metal-covered 6 by 36 foot Clark Y airfoil. Lead punching simulating 1/8 inch rivet heads were attached in full-span rows at a pitch of 1 inch at various chord positions. Tests were made at velocities varying from 40 to 120 miles per hour to investigate the scale effect" (p. 1).
Date: May 1933
Creator: Dearborn, Clinton H.
Partner: UNT Libraries Government Documents Department

Relative loading on biplane wings of unequal chords

Description: It is shown that the lift distribution for a biplane with unequal chords may be calculated by the method developed in NACA Technical report no. 458 if corrections are made for the inequality in chord lengths. The method is applied to four cases in which the upper chord was greater than the lower and good agreement is obtained between observed and calculated lift coefficients.
Date: May 18, 1934
Creator: Diehl, Walter S.
Partner: UNT Libraries Government Documents Department

An Experimental Investigation of the Normal Acceleration of an Airplane Model in a Gust

Description: Note presenting an investigation in the gust tunnel to determine the influence of airplane wing loading, forward velocity, wing plan form, and the fuselage on the reaction of the airplane to a known gust. Tests were made for four values of gust velocity and for two gust gradients, specifically the sharp-edge gust and a gust rising linearly to full strength in a distance of several chord lengths.
Date: May 1939
Creator: Donely, Philip
Partner: UNT Libraries Government Documents Department

Stability of Thin-Walled Tubes Under Torsion

Description: "In this report a theoretical solution is developed for the torsion on a round thin-walled tube for which the walls become unstable. The results of this theory are given by a few simple formulas and curves which cover all cases. The differential equations of equilibrium are derived in a simpler form than previously found, it being shown that many items can be neglected" (p. 3).
Date: May 5, 1933
Creator: Donnell, L. H.
Partner: UNT Libraries Government Documents Department

Computation of the two-dimensional flow in a laminar boundary layer

Description: A comparison is made of the boundary-layer flow computed by the approximate method developed by K. Pohlhausen with the exact solutions which have been published for several special cases. A modification of Pohlhausen's method has been developed which extends the range of application at the expense of some decrease in the accuracy of the approximations.
Date: May 1934
Creator: Dryden, Hugh L.
Partner: UNT Libraries Government Documents Department

The effect of area aspect ratio on the yawing moments of rudders at large angles of pitch on three fuselages

Description: This reports presents the results of measurements made of yawing moments produced by rudder displacement for seven rudders mounted on each of three fuselages at angles of pitch of 0 degree, 8 degrees, 12 degrees, 20 degrees, 30 degrees and 40 degrees. The dimensions of the rudders were selected to cover the range of areas and aspect ratios commonly used, while the ratios of rudder area to fin area and of rudder chord to fin chord were kept approximately constant. An important result of the measurements is to show that increased aspect ratio gives increased yawing moments for a given area, provided the maximum rudder displacement does not exceed 25 degrees. If large rudder displacements are used, the effect of aspect ratio is not so great.
Date: May 16, 1932
Creator: Dryden, Hugh L. & Monish, B. H.
Partner: UNT Libraries Government Documents Department

Chief Characteristics and Advantages of Tailless Airplanes

Description: This study will be concerned with the critical examination of two main questions, mainly, susceptibility of centering and more generally, the conditions of static stability, longitudinal equilibrium, and the question of dynamic stability, or at least the damping of longitudinal vibrations about a position of equilibrium that may result from a small variation in the angle of attack.
Date: May 1936
Creator: Dufaure De Lajarte, A.
Partner: UNT Libraries Government Documents Department