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open access

An Investigation of Aircraft Heaters 9: Measured and Predicted Performance of Two Exhaust Gas-Air Heat Exchangers and an Apparatus for Evaluating Exhaust Gas-Air Heat Exchangers

Description: Report presenting laboratory testing to determine the thermal output and pressure drop characteristics of the Airesearch and Solar fluted-type exhaust gas-air heat exchangers. The apparatus used in these tests consisted of a natural gas furnace of 3,000,000 Btu per hour thermal capacity, a centrifugal blower, and a system of ducting and various measuring devices. Results regarding the method of analysis, the Airesearch heat exchanger tests, the solar heat exchanger tests, and a comparison of th… more
Date: March 1943
Creator: Boelter, L. M. K.; Miller, M. A.; Sharp, W. H.; Morrin, E. H.; Iversen, H. W. & Mason, W. E.
open access

The effect of altitude on cooling

Description: Report presenting variables that control the cooling of liquid-cooled and air-cooled engines and then to show by illustrations how either engine may be cooled at any desired altitude. Cooling was found to not be the limiting factor in the design of high-altitude airplanes and was also not found to be a valid reason for selecting either liquid- or air-cooled engines for high-altitude operation.
Date: March 1943
Creator: Brevoort, Maurice J.; Joyner, Upshur T. & Wood, George P.
open access

A Theoretical Investigation of the Lateral Oscillations of an Airplane With Free Rudder With Special Reference to the Effect of Friction

Description: Report presenting charts showing the variation in dynamic stability with the rudder hinge-moment characteristics. A stabilizing rudder floating tendency combined with a high degree of aerodynamic balance is shown to lead to oscillations of increasing amplitude.
Date: March 1943
Creator: Greenberg, Harry & Sternfield, Leonard
open access

Comparative Yields of Light Oil, Tar, and Constituents from Carbonization Tests at 800 Degrees, 900 Degrees, and 1,000 Degrees Celsius

Description: Report issued by the U.S. Bureau of Mines on testing done on a variety of American coals collected from 32 coal beds across the country. The carbonizing properties of samples tested at 3 different temperatures are presented. This report includes tables, and graphs.
Date: March 1943
Creator: Holmes, C. R.; Wilson, J. E. & Davis, J. D.
open access

Radioactivity of the Cooling Water

Description: The most important source of radioactivity at the exit manifold of the pile will be due to O19, formed by neutron absorption of O18. A recent measurement of Fermi and Weil permits to estimate that it will be safe to stay about 80 minutes daily close to the exit manifolds without any shield. Estimates are given for the radioactivities from other sources -- both in the neighborhood and farther away from the pile.
Date: March 1, 1943
Creator: Wigner, Eugene Paul, 1902-1995.
open access

An investigation of aircraft heaters 10: measured and predicted performance of a fluted-type exhaust gas and air heat exchanger

Description: Report presenting performance data on a small exhaust gas and air heat exchanger. The heat transfer rates were measured using about 8000 pounds per hour of exhaust gas and 4300 pounds per hour of ventilating air. The thermal performance of heater no. 2 can be estimated to 3 to 17 percent by use of the method described in the report.
Date: March 1943
Creator: Boelter, L. M. K.; Dennison, H. G.; Guibert, A. G. & Morrin, E. H.
open access

An Investigation of Aircraft Heaters 8: A Simplified Method for the Calculation of the Unit Thermal Conductance Over Wings

Description: Report presenting a simplified approximate method of calculating the unit thermal conductance along an airfoil as a function of distance from the leading edge, by use of heat transfer data for smooth cylinders and smooth flat plates. Several examples are used in order to show the effectiveness of the method.
Date: March 1943
Creator: Martinelli, R. C.; Guibert, A. G.; Morrin, E. H. & Boelter, L. M. K.
open access

Wind-Tunnel Investigation of Trimming Tabs on a Thickened and Beveled Aileron on a Tapered Low-Drag Wing

Description: Report presenting an investigation in the 7- by 10-foot tunnel of three inset tabs and of one attached tab on the beveled aileron of a low-drag wing. The results indicated that, of the arrangements tested, an inset tab with a chord 50 percent of the aileron chord provided the most satisfactory trimming characteristics on a beveled aileron.
Date: March 1943
Creator: Rogallo, F. M. & Crandall, Stewart M.
open access

A Correlation of the Dimensions, Proportions, and Loadings of Existing Seaplane Floats and Flying Boat Hulls

Description: Report presenting a study to determine what loadings and proportions have been chosen by designers of seaplanes and flying boats and what, if any, interrelations exist between the loadings and proportions. The characteristics considered include the beam, getaway speed, forebody length, afterbody length, hull length, center of gravity, and brake horsepower necessary.
Date: March 1943
Creator: Locke, Fred W. S., Jr.
open access

The Effect of Spinner-Body Gap on the Pressures Available for Cooling in the NACA E-Type Cowling

Description: "Tests of a 1/3-scale model of an NACA E-type cowling were made in the 8-foot high-speed tunnel for the purpose of determining the effect of the gap between the skirt of the hollow spinner and the cowling proper on the pressures available for cooling. It was found that even a large gap (0.096 in. on the model) had no appreciable effect on the available cooling pressures" (p. 1).
Date: March 1943
Creator: Becker, John V. & Mattson, Axel T.
open access

Effects of Prior Fatigue-Stressing of the Impact Resistance of Chromium-Molybdenum Aircraft Steel

Description: Note presenting a study of the impact behavior of normalized SAE X4130 steel after a variety of repeated stress treatments. Fatigue specimens of several types were used and the effects of surface finish, rest periods, stress amplitude, mean stress, stress concentration, and temperature during repeated stress received consideration.
Date: March 1943
Creator: Kies, J. A. & Holshouser, W. L.
open access

Turbulent Flow Between Rotating Cylinders

Description: "The turbulent air flow between rotating cylinders was investigated. The distributions of mean speed and of turbulence were measured in the gap between a rotating inner and a stationary outer cylinder. The measurements led to the conclusion that the turbulent flow in the gap cannot be considered two dimensional, but that a particular type of secondary motion takes place. It is shown that the experimentally found velocity distribution can be fully understood under the assumption that this second… more
Date: March 1943
Creator: Shih-I, Pai
open access

Torsion of flanged members with cross sections restrained against warping

Description: "The longitudinal stresses and the stiffness of flange members - I-beams, channels, and Z-bars - were investigated when these members were subjected to torque with constraint against cross-sectional warping. Measured angles of rotation agreed with corresponding calculated values in which the torsion bending factor of the cross section was involved; the agreement was better for the I-beam and the Z-bar than for the channel. Longitudinal stresses measured at the mid-span were found to agree with … more
Date: March 1943
Creator: Hill, H. N.
open access

A Theoretical Investigation of the Lateral Oscillations of an Airplane With Free Rudder With Special Reference to the Effect of Friction

Description: "Charts showing the variation in dynamic stability with the rudder hinge-moment characteristics are presented. A stabilizing rudder floating tendency combined with a high degree of aerodynamic balance is shown to lead to oscillations of increasing amplitude. This dynamic instability is increased by viscous-friction in the rudder control system" (p. 147).
Date: March 4, 1943
Creator: Greenberg, Harry & Sternfield, Leonard
open access

A method for studying piston friction

Description: From Introduction: "The purpose of this investigation was to develop a method for determining directly the friction force between the piston and cylinder of an internal combustion engine. The method consists in elastically mounting the cylinder barrel so that it can have a small motion parallel to its axis, and providing suitable means for recording its instantaneous displacement."
Date: March 1943
Creator: Forbes, J. E. & Taylor, E. S.
open access

Tests of a dynamic model in NACA tank number 1 to determine the effect of length of afterbody, angle of afterbody keel, gross load, and a pointed step on landing and planning stability

Description: Report presenting testing in tank no. 1 to determine the effect of length of afterbody, angle of afterbody keel, and gross load on the limits of stable trims and landing characteristics of a model of a flying boat with conventional steps. The studies were made with four lengths of afterbody, four angles of afterbody keel, and five gross loads. Results regarding the trim limits of stability and landing stability are provided.
Date: March 1943
Creator: Land, Norman S. & Lina, Lindsay J.
open access

XC-35 gust research project: Preliminary analysis of the lateral distribution of gust velocity along the span of an airplane

Description: Report presenting measurements of the lateral distribution of effective gust velocity along the span of the XC-35 airplane in a variety of weather conditions. Six standard shapes were determined from the distributions: triangular, rectangular, first trapezoidal, second trapezoidal, unsymmetrical, and double triangular.
Date: March 1943
Creator: Moskovitz, A. I.
open access

Investigation of the Longitudinal Stability at High Speeds of a 1/5-Scale Model of a Tailless Pursuit Airplane

Description: "Tests of a tailless pursuit airplane model at the Ames Aeronautical Laboratory have shown that in conditions corresponding to level flight at a Mach number less than 0.7 and at an altitude under 35,000 feet, no serious compressibility effects occurred and that no sudden adverse diving moments were encountered up to a Mach number of 0.74, the maximum speed of the tests. However, there were indications that the elevons might lose their effectiveness for longitudinal control during a pull-out fro… more
Date: March 1943
Creator: Laitone, Edmund V.
open access

Wind-Tunnel Tests of Two Tapered Wings with Straight Trailing Edges and with Constant-Chord Center Sections of Different Spans

Description: Report presenting tests made in the 19-foot pressure tunnel to determine the aerodynamic characteristics of two tapered wings with NACA 230-series airfoil sections, constant-chord center sections, and straight trailing edges. Lift, drag, and pitching-moment characteristics of the wings with partial-span and full-span split flaps are given for a test Reynolds number of 4,600,000.
Date: March 1943
Creator: Neely, Robert H.
open access

Studies on the Electrolytic Reduction of Nitric Acid

Description: Report discussing the reduction of nitric acid that results from its use at the cathode for the electrolysis of uranyl nitrate. From introduction: "It is the purpose of this report to give the results of studies on the reduction of nitric acid of different concentrations, at different types of electrodes, and for various current densities in order to ascertain the effects of such changes."
Date: March 27, 1943
Creator: Hamer, Walter J.
open access

Optimum Design of Catalytic Towers

Description: Abstract: "This paper gives an arithmetic method of computing the number of sections required in a catalytic tower to produce a given enrichment. It also tells how to calculate the enrichment of a tower with a given number of sections. The problem of the most economical design of catalytic towers is solved. Methods are given for determining the temperature, the efficiencies of catalyst beds and strippers, the relative production rate, and the water vapor-hydrogen gas ratio which give the optimu… more
Date: March 13, 1943
Creator: Mayer, Harris
open access

A simplified chart for determining Mach number and true airspeed from airspeed-indicator readings

Description: "The determination of flight Mach number from measurements of indicated airspeed and pressure altitude is shown to be relatively simple and leads to direct and accurate computation of true airspeed. A simplified chart is presented for determining flight Mach number and true airspeed for a range of values of indicated airspeed, pressure altitude, and air temperature. A table of standard atmospheric values is included" (p. 1).
Date: March 1943
Creator: Baals, Donald D. & Ritchie, Virgil S.
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