"From a review of the different similarity approaches to compressible potential flow, the meaning and limitations of transonic similarity are traced back to their origin. Although the main text deals with the quasi two-dimensional flow, special suggestions for the case of axisymmetric bodies are added in an appendix" (p. 1).

Note presenting the statistical concepts of random variables and probability distributions as applied to the sharp edge gust formula as a basis for the prediction of the gust-load history of airplanes in service operations. The results are applied in an example and the predicted load experience is compared with the available flight loads data for the case.

Note presenting an expression developed for the lift of a slender afterbody in terms of the "slender-body" approximate potential at the after end in conjunction with a suitably calculated value of the potential at the forward end. The same expression is used to compute the part of the interference lift generated by the presence of a neighboring body, due to the interference upwash. The lift is determined for a cone-cylinder body, a cylindrical afterbody of a slender wing-body combination, and three combinations of bodies to illustrate the method.

Report presenting a simplified method for the solution of two-dimensional compressible flows through well-defined passages. Pressure distributions around four cascades of turbine blades and along the surface of a choked nozzle determined by the method are shown to compare well with experimental results.

Report presenting the results of an investigation of condensation phenomena in supersonic wind tunnel. Lower and upper limits for the degree of supersaturation attainable before the onset of condensation of air are discussed. A method is presented for calculating the properties of a stream containing a small fraction of condensed air.

"An investigation has been conducted to determine experimentally the effects of compressibility on the flow past a bump and to compare the experimentally determined results with theory. Pressure measurements and Schlieren photographs were made of the flow past two bumps having thickness-chord ratios of 0.10 and 0.30 at Mach numbers between 0.20 and 0.84" (p. 1).

Report presenting an experimental investigation in order to determine the performance of a 90 degree cascade diffusing bend with an area ratio of 1.45:1, a 19-by-19-inch inlet, and five inlet boundary layers varying in thickness and shape parameter. Tests were performed over a range of Mach and Reynolds numbers. Results regarding velocity distribution, performance, and some general considerations for this configuration are provided.

Report presenting an investigation of boundary-layer suction through flush surface slots as a means for increasing the extent of laminar flow on the NACA 64A010 airfoil section. Results regarding slot modifications, suction distribution, and drag results are provided.

Note presenting wind-tunnel tests of the heat-transfer characteristics of the laminar and turbulent boundary layers on a cooled flat plate conducted at a nominal Mach number of 2.4. Data were obtained for a range of Reynolds numbers and nominal surface temperatures. Results regarding the Mach number distribution on flat-plate model, surface temperatures and heat-transfer rates, boundary-layer velocities profiles, temperature-recovery factor, and heat-transfer characteristics are provided.

Note presenting analytical expressions derived for the flapping, thrust, torque, and profile-drag power of a hinged rotor that are applicable to high-speed helicopters and to certain types of convertible aircraft.

Report presenting the laminar flame speed of 2,2,4-trimethylpentane with various oxygen-nitrogen mixtures as determined from schileren photographs of Bunsen-type flames. Some experimental results and theoretical predictions are provided. Testing occurred at 311 and 422 degrees Kelvin.

Note presenting several known methods of controlling the entry and exit of hydrogen in steel as correlated with the known chemical behavior of atomic and molecular hydrogen. Some of the results of testing and a newly proposed mechanism for hydrogen control are provided.

"An analysis of the gust and gust-load experience of a low-altitude transcontinental transport airplane, based on 834 hours of VGH record, is presented. The relation of gust experience to airspeed, altitude, season of the year, and flight condition is considered. An estimate of the overall gust history for the present type of operations is derived from a synthesis of the VGH data and available V-G data" (p. 1).

Low-speed pressure-recovery and surface-pressure measurements for a twin fuselage-side air-inlet arrangement intended for use at transonic speeds are presented. The model was developed by adding a canopy and nose-wheel fairing to basic transonic annular inlet studied in TN 2685. The results indicate shape requirements of fuselage nose, canopy, and nose-wheel fairing for maintaining substream surface velocities everywhere ahead of entrance.

Low-speed wind-tunnel tests were conducted as preliminary steps in the study of fuselage-air-inlet arrangements believed suitable for use at transonic speeds. The forward part of the model consisted of an NACA 1-85-050 cowling located at the base of the long protruding fuselage nose designed to maintain substream surface velocities everywhere ahead of the entrance and thereby to avoid or minimize adverse boundary-layer-shock interaction effects up to low supersonic speeds. Pressure-recovery and surface-pressure measurements are presented for the model with three fuselage nose shapes for ranges of angle of attack and inlet-velocity ratio useful for high-speed flight.

"A variable-air-gap, inductance-type, electrical pressure gage is described that is basically 7/16 inch in diameter and 1/4 inch in thickness. The gage was designed to measure accurately pressures fluctuating at high frequencies and has proved to be a value as a general-purpose electrical gage for aeronautical work where small size and minimum response to acceleration forces are important factors. Design equations and curves are presented which can be used to predict the deflections and fundamental natural frequencies of stretched flat diaphragms" (p. 1).

"A theory for the elastic behavior of orthotropic sandwich plates is used to determine the compressive-buckling-load parameters of flat systemic corrugated-core-sandwich plates with simply supported loaded edges and simply supported or clamped unloaded edges. Charts are presented for corrugated-core sandwich plates for which the transverse shear stiffness in planes parallel to the axis of the corrugations may be assumed infinite. The limits of validity of this assumption are investigated for simply supported plates" (p. 1).

Note presenting an analysis of the one-dimensional compressible flow in a rotating radial-plane impeller channel conducted in order to provide an insight into the characteristics of the passage mean flow under the influence of centrifugal forces and losses.

Report presenting a theory and method for the application of interferometry to the measurement of certain two-dimensional gaseous density fields. The theory includes the effects of optical refraction on the observed interference pattern.

From Summary: "A method is presented for obtaining three-dimensional unsymmetric supersonic nozzles and inlets from known axisymmetric flows. Stream-lines bounding the desired exit shape are traced through the known basic flow solution to give the required unsymmetric wall contours. Several examples are given."

Report presenting the development of an exact theoretical method that permits the determination of the pressure field of a wing-body combination with a circular body and a wing with supersonic leading and trailing edges. Detailed calculations were performed for wing-body combinations composed of rectangular wings mounted at incidence on bodies at zero angle of attack for effective chord-radius ratios of 4 or less.