From Summary: "The aerodynamic design of propellers from considerations of centrifugal force is presented. By applying a constant minimum value of thickness ratio from root to tip and allowing the distribution of required area to appear in the blade plan form, propellers with good efficiency are realized at high Mach numbers by the method of this paper."

Note presenting the measurement of the constant-pressure specific heat of carbon dioxide over the range of pressures and temperatures from ambient conditions to 1000 pounds per square inch gage and 1000 degrees Fahrenheit using a steady-flow calorimeter operating on an open cycle. The results of the tests check the widely accepted spectroscopic data within 1 percent. Results regarding the validity of results, presentation of results, and limitations of the calorimeter are provided.

Note presenting an analysis of the corrections for lift, drag, and moment of a two-dimensional airfoil as tested in the working section of a supersonic tunnel in which the pressure field, instead of being uniform, is characterized by gradients in the axial and transverse directions. The pressure gradients of the tunnel as well as the effect of the airfoil to be tested are regarded as perturbations of the original rectilinear flow field of given Mach number.

Report presenting an exploration of synthetic lubricants, which involved studying the effects of a wide range of sliding velocities on boundary lubrication. The data showed that a number of synthetics, including diesters, polyethers, a silicate ester, and a phosphonate ester as well as a silicone-diester blend are more effective boundary lubricants at high sliding velocities than comparable petroleum oils.

An experimental investigation was conducted to determine the temperature profiles downstream of heated air jets directed at angles of 90 deg, 60 deg, 45 deg, and 30 deg to an air stream. The profiles were determined at two positions downstream of the jet as a function of jet diameter, jet density, jet velocity, free-stream density, free-stream velocity, jet total temperature, orifice flow coefficient, and jet angle. A method is presented which yields a good approximation of the temperature profile in terms of the flow and geometric conditions.

"The influence of nonmartensitic transformations products on the mechanical properties of tempered martensite is presented for samples of a SAE 4340 steel, partially isothermally transformed to specific high-temperature transformation products and quenched and tempered to hardness values of from 25 to 40 Rockwell C. The effects of upper bainite in amounts of 1,5, 10, 20 and 50 percent, of 5 percent ferrite, and of 5 percent pearlite on the tensile, impact, and fatigue properties are evaluated" (p. 1).

"The complex problem of the interaction between shock waves and boundary layers in supersonic flow is not yet clearly understood, despite a number of theoretical studies. Among these, the analysis of Tsein and Finston is singled out here for further examination. In the Tsien-Finston model the boundary layer is simulated by a uniform subsonic stream of finite width bounded on one side by a solid wall and on the other side by the interface with a uniform supersonic stream of semi-infinite extent" (p. 2).

Report presenting two 75-millimeter-bore inner-race-riding cage-type ball bearings were used in an experimental investigation of the effects of load, oil flow, and oil inlet conditions on bearing operating characteristics over a range of DN values.

Report presenting the study of spontaneous ignition characteristics of organic compounds with emphasis on the various types of lubricating oils. Results regarding the spontaneous ignition temperatures of the lubricants, pure compounds, effects of additives on spontaneous ignition temperatures, spontaneous ignition temperatures of mixtures and effects of additives, and effect of metal surfaces on spontaneous ignition temperatures are provided.

"A study has been made of the heat requirement for the cyclic de-icing of hollow steel propellers fitted with external blade heating shoes. Solutions to the equations for the heat flow in cyclic heating of propellers were obtained, using an electrical analogy. The study showed how the energy requirement for propeller de-icing with existing blade shoes could be decreased, and illustrated the effect of blade-shoe design on the energy requirement. It was demonstrated, for example, that by increasing the heating intensity and decreasing the heating period from those currently used the energy requirement could be decreased in the order of 60 percent" (p. 1).

Note presenting an analysis of the natural-convection phenomenon, which shows that the flow and heat transfer, in general, are not only functions of the Prandtl and Grashof numbers but also depend on a new dimensionless parameter. If the parameter is not negligibly small, the compression work and frictional heating may appreciably affect this mode of heat transfer. Results regarding the velocity and temperature distributions and heat transfer are provided.

This paper contains a detailed description of a 2,000-horsepower propeller dynamometer used to make wind-tunnel tests of a two-blade NACA 10-(3)(08)-03 propeller for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. The results of these tests and comparisons with results obtained from a theoretical analysis and from previous tests made in other wind tunnels are presented.

Report presenting an experimental investigation with a surface with a dead rise angle of 40 degrees and horizontal chine flare to determine the effects of increasing the angle of dead rise on the planing characteristics of horizontally flared prismatic surfaces. Wetted length, resistance, center-of-pressure location, and draft were determined for a range of speed coefficients and trims. Planing characteristics for a given trim were found to depend mainly on lift coefficient.

A study is presented of the geometric configuration factors required for computing radiant heat transfer between opaque surfaces separated by a nonabsorbing medium and various methods of determining the configuration factors are discussed. Configuration-factor solutions available in the literature have been checked and the more complicated equations are presented as families of curves. Cases for point, line, and finite-area sources are worked out over a wide range of geometric proportions.

Report presenting an investigation at low speed of the two-dimensional aerodynamic characteristics of a 10.51-percent-thick symmetrical airfoil with area suction near the leading edge. The chordwise extent and distribution of porosity were adjusted in order to obtain a low quantity of suction-air flow for the maximum possible lift. Results regarding the plain wing, wing with various chordwise extents of area suction, wing with area suction from the leading edge to 3-percent chord, boundary-layer measurements, and stagnation location are provided.

Report presenting the theoretical spanwise distributions of circulation resulting from constant angle of attack, steady rolling velocity, steady pitching velocity, and constant vertical acceleration calculated for a series of thin, sweptback, tapered wings with streamwise tips.

Report presenting the supersonic wave draw of a nonlifting, symmetrical, double-wedge-profile, delta wing with a linearly varying thickness ratio as calculated by the use of linear theory. It was found that a delta wing with linearly varying thickness ratio can have less wave drag than a similar wing with a constant thickness ratio.

Report presenting a method for investigating the effects of the dynamic response of an autopilot on the stability of an aircraft-autopilot combination. The effects of the stability of variations in the gain, natural frequency, and damping ratio of the autopilot are explored.

Report presenting a theoretical study of the aerodynamic characteristics at small angle of attack of a thin, double-wedge profile in the range of supersonic flight speed in which the bow wave is detached. The calculations provide, for extremely small angles of attack, the following information as a function of the transonic similarity parameter: chordwise lift distribution, lift-curve slope, and position of center of lift.

Report describing an instrument based on the principle that an x-ray beam is essentially undeviated while traversing a short path in air. It was used to measure the product of air density and the path length in the 10- by 14-inch supersonic wind tunnel. The measurements obtained were accomplished by comparing the intensity of two beams from the same X-ray source.

Note presenting normal-acceleration and airspeed data obtained for one type of twin-engine transport airplane in commercial operations in order to determine the gust and gust-load experiences of the airplane. Results regarding acceleration experience, gust experience, seasonal effects, and effect of special operating restriction are provided.

From Introduction: "It is shown in the body of this report that the solution to the error problem depends upon a more or less arbitrary definition, the only criterion as to the choice of the definition being the usefulness of the solution to which it leads. In this respect, it may be said of the method derived herein that it is not difficult to apply and appears to lead reasonable values of the errors."

Note presenting the general equations governing the fixed-trim water landing of a straight-keel seaplane with a hull of arbitrary constant cross section in such a form that the landing motions and loads are expressed in terms of the steady planing characteristics of the seaplane.

Report presenting the constant-temperature hot-wire anemometer amplifier and accessories have been developed to provide an instrument with wide frequency response, good stability, and ease of operation. Techniques are described using the equipment to study periodic phenomena such as surge, rotating stall, and wake surveys in centrifugal- and axial-flow compressors.