Note presenting tables of thermal properties of molecular nitrogen that have been prepared in an NBS-NACA series and grouped together for convenient use. Some of the properties include the thermodynamic functions for the gas, both real and ideal, the transport properties for the gas, and the vapor pressure of the liquid and the solid.

Note presenting tables based on the Lennard-Jones 6-12 potential for nonpolar molecules to be used in the representation of second and third virial coefficients and equation-of-state corrections for enthalpy, entropy, specific heats at constant volume and at constant pressure, the ratio of specific heats, the isentropic expansion coefficient, and the velocity of sound.

Report presenting the effect of leading-edge geometry on transition position, recovery-factor distribution, boundary-layer profile, and the roughness required to induce transition at Mach number 3.1 for a hollow cylinder aligned with the air stream. Results regarding leading-edge effect, roughness elements in laminary boundary layer, surface-heat condition effects, and effect of stream total temperature are provided.

Note presenting a theoretical analysis of the relations between wake characteristics and total-pressure defect for the incompressible flow across a two-dimensional cascade of compressor blades. Results indicated that the total-pressure-loss coefficient for unseparated flow varied almost directly with the ratio of wake momentum thickness to blade chord length and with the solidity, and inversely with the cosine of the air outlet angle.

Note presenting large downstream movements of transition observed when the leading edge of a hollow cylinder or a flat plate is slightly blunted are explained in terms of the reduction in Reynolds number at the outer edge of the boundary layer due to the detached shock wave. The hypothesis is made that transition Reynolds number is substantially unchanged when a sharp leading edge or tip is blunted.

Report presenting an investigation of a method for producing hypersonic flow in a wind tunnel by using the hot gaseous products obtained from the thermal decomposition of nitrous oxide. Testing was conducted at a variety of temperatures and pressures.

Report presenting measurements made of the flow around a 10-percent-thick, double symmetrical, two-dimensional wedge at Mach number 1.30 and a 14.2-percent-thick wedge at two Mach numbers for various angles of attack. Pressure and Mach number distributions, lift and drag coefficients, center of lift, and pitching moment are presented.

Report presenting measurements of unsteady-flow turbulent boundary-layer characteristics for artificially thickened boundary layers using a new optical technique involving the bow-wave shape of bullets fired in a shock tube. Measurements using several different methods are compared in the study. Results regarding boundary-layer measurements, velocity-profile measurements, attenuation measurements, pipe-flow effect, and qualification of results are provided.

Report presenting an investigation of the effects of ground proximity and propeller position on the effectiveness of a wing equipped with large-chord slotted flaps in redirecting the slipstreams from large-diameter propellers downward for vertical take-off. Results regarding the characteristics of basic configuration in the ground-effect region, effect of propeller position, comparison of characteristics of one- and two-propeller models, characteristics of modified configuration, and effect of ground on propeller characteristics are provided.

From Summary: "Results are presented of axial-load fatigue tests at stress ratios of 0 and -1.0 on electropolished 2024-T3 (24S-T3) and 7075-T6 (75S-T6) aluminum-alloy-sheet specimens with central holes. The specimen widths and hole diameters were varied in order to provide data suitable for a study of the effect of notch size. The data are compared with previously published results of tests on unnotched electropolished specimens and on unpolished specimens containing central holes."

From Introduction: "The results are presented in the form of a structural-efficiency chart where minimum structural weight is plotted as a function of the structural index for constant values of the ratio of wing depth to skin thickness."

Report presenting an analysis of the use of linked leading-edge and trailing-edge flap-type controls for the purpose of reducing hinge moments at supersonic speeds. A series of linked controls with supersonic leading and trailing edges on swept and unswept wings has been studied for several Mach numbers by use of the linearized theory of supersonic flows. Results regarding hinge moment and hinge-moment reduction and lift and rolling moment are provided.

Note presenting a theoretical derivation for the effect of a towing-carriage mass upon the general equations of motion for a prismatic body during a hydrodynamic impact. The equations can be used at any stage of the impact to determine the resulting loads and motions of the body, including the effect of a carriage mass. Results regarding a nonimmersed chine and an immersed chine are provided.

"A miniature rocket motor was designed and developed to produce 3 ounces of thrust for a duration of 2 seconds. The rocket is simply designed, safe to operate, easily handled, and gives reproducible performance. Standard solid-propellant-rocket design techniques were found to be not wholly applicable to the design of miniature rockets because of excessive heat losses" (p. 1).

Report presenting the results of an exploratory, analytical, and experimental study of some of the factors that can be important in the stall flutter of thin wings. Some of the factors considered were Mach number, Reynolds number, density, aspect ratio, sweepback, structural damping, location of torsion nodal line, and concentrated tip weights. Some of the factors were considered to be more or less significant, but all require further study.

Report presenting an evaluation of the local coefficients of convective heat transfer from skin temperature on the body of an NACA research missile. Aerodynamic heating has been recognized as a major problem in the design of supersonic aircraft and experimental data has been greatly sought after. Results regarding recovery factors, the equation for thermal conductance, air viscosity, and the heat transfer parameters are provided.

From Introduction: "This study was the basis for the present paper which deals with means for compensating the roll and yaw response to side gusts of a fighter airplane in combination with an autopilot. Results are presented which compare the response to side gusts of the original and compensating autopilots; the responses to commands are presented also."

Note presenting theoretically derived charts showing steady-state and first- and second-harmonic flapping coefficients for helicopter rotors with hinged rectangular blades with a linear twist of 0, -8, and -16 degrees. The charts, showing the rotor flapping coefficients for combinations of inflow ratio and blade pitch angle, are presented for tip-speed ratios ranging from 0.05 to 0.50.

Report presenting a low-speed investigation in the stability tunnel to determine the directional stability characteristics of tandem nonoverlap-type helicopter fuselages without rotors. The investigation consisted of both bent and straight fuselages with either circular or elliptical cross sections and with two vertical-tail sizes.

Report presenting tests of a group of related NACA airfoil sections varying in maximum thickness, design lift coefficient, and thickness distribution in a two-dimensional open-throat wind tunnel at a range of Mach numbers. Normal-force, drag, and pitching-moment coefficients are presented with representative schileren photographs and pressure-distribution diagrams.

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.

Note presenting the lifting-surface sidewash behind rolling triangular wings for a range of supersonic Mach numbers for which the wing leading edges remain swept behind the Mach cone emanating from the wing apex. Variations of the sidewash with longitudinal distance in the vertical plane of symmetry are presented in graphical form.

Report presenting a method to compute the contour of a body for a prescribed pressure distribution based on the theory of characteristics. A mode was constructed with an initial included cone angle of 30 degrees and a contour to give a linear pressure distribution for a free-stream Mach number of 3.13.

Note presenting the measurement of relaxation times for the excitation of molecular vibrations in a number of heavy gases using an acoustic interferometer. All of the gases studied were found to have a single relaxation time, indicating that intermodal coupling in these gases is strong.