Report presenting a theoretical approach to determine the lateral frequency response of a fighter airplane to side gusts and rolling gusts at a Mach number of 0.7 and an altitude of 30,000 feet. Frequency response and power spectral density were determined with the controls fixed and in combination with three different basic types of attitude autopilots.

"By use of an approximate equation for the wave drag of slender bodies of revolution in a supersonic flow field, the optimum shapes of certain boattail bodies are determined for minimum wave drag. The properties of three specific families of bodies are determined, the first family consisting of bodies having a given length and base area and a contour passing through a prescribed point between the nose and base, the second family having fixed length, base area, and maximum area, and the third family having given length, volume, and base area. The method presented is easily generalized to determine minimum-wave-drag profile shapes which have contours that must pass through any prescribed number of points" (p. 1).

From Introduction: "The analysis of flight data in the present report is, to a large extent, based on analyses and information contained in references 1 and 2 for wing deflections, reference 3 for horizontal-tail parameters, reference 4 for airplane lift-curve slopes and angles of zero lift, and reference 5 for wing centers of pressure."

"The primary objectives of the present paper are to report the horizontal-tail-loads measurements for configuration B which have not previously been reported and to summarize the horizontal-tail-loads results obtained with both configurations. The manner in which the aerodynamic-loads data were analyzed to include structural temperature effects and fuselage flexibility effects constitutes an important part of the present paper" (p. 1).

Report presenting a series method of determining two-dimensional vortex paths is considered and applied to the computation of vortex positions behind a slender equal-span cruciform wing at any angle of bank as a function of the distance behind the trailing edge.

Report presenting a theoretical treatment of absorption problems that considers the following cases: radiation is normal to an absorber with plane parallel surfaces, radiations are of several polyenergetic types, induced radioactive isotopes decay to stable atoms in multistep decay processes, and radiations from the absorber affect the time-dependency of the source activity. Radiation from intermediate isotopes can become more dangerous than the original activity, so the entire range of radiations must be accounted for.

Report presenting tables for determining the total-absorption coefficients as well was the intensities and spectral distribution of gamma rays at any scattering angle. Both experimental and computed data on gamma rays of quantum energies up to 20 million electron volts for all elements which have significant data available are provided. The accuracy of results is obtained by the use of tables.

Report presenting friction and wear experiments conducted to explore the effects of high temperature, varied chlorine content, sulfur catalysis, and preformation of sulfide films on boundary lubrication with reactive gases. Results regarding sulfur hexafluoride, dichlorodifluoromethane, chlorotrifluoromethane, chlorotrifluorometahne plus sulfur hexafluoride, and dichlorodifluoromethane plus sulfur hexafluoride are provided.

Report presenting the development of an asymmetric type of adjustable supersonic nozzle suitable for application to wind tunnels. This type of nozzle permits continuous adjustment of the test-section Mach number without the requirement of flexible walls.

From Summary: "An analysis is given of the oscillating motion of a ballistic missile which upon entering the atmosphere is angularly misaligned with respect to the flight path. The history of the motion for some example missiles is discussed from the point of view of the effect of the motion on the aerodynamic heating and loading. The miss distance at the target due to misalignment and to small accidental trim angles is treated. The stability problem is also discussed for the case where the missile is tumbling prior to atmospheric entry."

A simplified analysis of the velocity and deceleration history of missiles entering the earth's atmosphere at high supersonic speeds is presented. The results of this motion analysis are employed to indicate means available to the designer for minimizing aerodynamic heating. The heating problem considered involves not only the total heat transferred to a missile by convection, but also the maximum average and local time rates of convective heat transfer.

Report presenting a visualization study using smoke to see the secondary-flow phenomena in the rotor-blade tip region of a low-speed turbine. Measurements of the factors affecting the flow patterns were recorded from visual observations. Results regarding a general description of the smoke patterns, shroud boundary-layer considerations, transition rotor tip speed, and high-speed-turbine operating conditions are provided.

"A method is presented for the computation and graphic representation of a series of possible turbine designs for any specific application. The use of a preliminary design chart is suggested for determining the number of stages and the effects of exit whirl and annular-area divergence on possible configurations. A specific design chart can then be made to aid in the study of the relations between turbine radius ratio, diameter, and significant design parameters such as Mach numbers, turning angles, and blade root stresses" (p. 1).

Note presenting an experimental investigation in which measurements were made of the turbulent boundary layer of a two-dimensional unswept wing and a comparable wing swept 45 degrees. The results indicate the applicability of simple sweep theory for determining turbulent boundary-layer growth on the swept wing for a lift coefficient of zero.

Report presenting calculations and flight-test measurements on a single-main-rotor helicopter indicate that the damping moment about the helicopter center of gravity produced during pitching or rolling by a rotor which has flapping hinges on the rotor shaft, which depends primarily on four quantities: rotor speed, blade mass factor, height of the rotor hub above the helicopter center of gravity, and the ratio of collective pitch to the thrust coefficient - solidity ratio.

Report presenting charts to provide a convenient means for obtaining the derivatives of rotor resultant force, rotor pitching amount about the helicopter center of gravity, and rotor torque with respect to rotor angle of attack, forward speed, rotor speed, and collective pitch.

Note presenting pressure-distribution measurements made on a 5-inch-chord NACA 0012 airfoil at zero angle of attack in the Langley rectangular high-speed tunnel, a 4- by 18-inch closed-throat tunnel, and compared with results calculated by Emmons for an equivalent airfoil-channel configuration by using the relaxation method.

Note presenting a consideration of a wing-selection problem sometimes encountered in the preliminary design of supersonic airplanes and missiles. The problem is to determine the span, section thickness ratio, and skin thickness or hollowness ratio of the wing of least drag when the plan form, section shape, wing lift requirement, and flight conditions are assumed known. An example of the application of the method to a diamond wing at Mach number 2.0 for a range of specified flight conditions is presented.

Note presenting measurements of ignition delays for mixtures of ethane, n-butane, isobutane, hydrogen, or propane with oxygen and nitrogen using a flow system with two experimental procedures. Delays were measured over a range of temperatures for each gas. Results regarding a comparison among fuels and effect of experimental procedure on absolute values of ignition delay are provided.

"A method is presented for calculating crippling stresses of structural sections as a function of material properties and the proportions of the section. The presence of formed or anisotropic material is accounted for by the use of an effective stress-strain curve. The method of analysis applies to many sections for which a procedure for calculating crippling was not previously available" (p. 1).

The charts presented give the compressive buckling coefficients for a single-truss-core and a double-truss-core sandwich plate. These charts cover a wide range of sandwich proportions and may be used for sandwiches with unequal faces. They apply to inplane compressive loads acting parallel or perpendicular to the core direction or for various combinations of these loads. (author).

"The results of compressive-buckling tests of steel sandwich plates are given, and the significant parameters which affect the strength of the plates are discussed. The various types of sandwich construction are shown to be comparable on a weight-strength basis with conventional high-strength aluminum-alloy construction" (p. 1).

"Charts giving the compressive-buckling stress coefficients for sheet panels of a shape occurring in swept-wing plan forms are presented. The panels are assumed to be a part of a continuous flat sheet divided by nondeflecting supports into parallelogram-shaped areas. The stability analysis was performed by the energy method and the results show that, over a wide range of panel aspect ratio, such panels are decidedly more stable than equivalent rectangular panels of the same area" (p. 1).

"A correlation approach to the crippling-strength analysis of plate structures in new materials and at elevated temperatures is presented. Appropriately defined crippling-strength moduli and correlation procedures are given for predicting the effect of a change in material properties on the strength of a structure. The strength moduli are readily calculated from the effective compressive stress-strain curve for the structural material" (p. 1).