"The accuracy of the substitute-stringer approach for including the effects of shear lag in the calculation of the transverse modes and frequencies of multistringer box beams is investigated. Box beams, the covers of which consist of normal-stress-carrying stringers on sheets which carry not only shear but also normal stress, are analyzed exactly. Frequencies of beams with various numbers of stringers, obtained by means of this exact analysis, serve to determine the possible accuracy of the frequencies obtained by the substitute-stringer approach" (p. 1).

From Introduction: " Considerable analytical and experimental research has been done to find means of reducing the noise levels of the turbojet transports. Noise levels can be decreased by engine redesign to reduce the jet-exit velocity (ref. 1), proper flight-climb techniques (ref. 2), and the use of noise-suppression exhaust nozzles (refs. 3 to 5). The present report is concerned with the last method."

Report presenting an investigation of the two-dimensional aerodynamic characteristics of three airfoil sections formed by removing various portions of the original chord from the trailing edge of the NACA 0012 airfoil section. Results regarding lift, drag, and pitching moment and aerodynamic center are provided.

From Introduction: "This paper presents the basic design method and experimental results of calibration of a nozzle which was constructed to conform to the analytically determined ordinates."

From Introduction: "The time-averaged flows are considerably simpler to deal with theoretically than are the instantaneous flows, and the results of several theoretical analyses are available (refs. 2 to 6, for example). Several previous experimental investigations (see ref. 7 for a bibliography) have provided some qualitative information on the subject by the use of smoke in flight and in wind tunnels. However, quantitative measurements (refs. 8 to 10) are extremely scarce and, in general, are inadequate either to define the nature of the flow or to check the accuracy of the theoretical calculations."

From Introduction: "In this paper are presented descriptions of the camera setups and associated equipment, the equations and methods used in determining the model attitudes and motions from the film, and time-history curves of the variables of the spin and recovery investigated. Discussions of the nature of the spin and recovery obtained and of factors ostensibly affecting these motions are included."

From Introduction: "In the present paper, general ejector equations (see reference 4 or 5) and certain assumptions with regard to flow conditions and pressure losses have been utilized to calculate the running times of induction blowdown supersonic tunnels operating in the mentioned Mach number range."

From Introduction: "The purpose of the present paper is to present summary of the information gleaned from various transonic-bump investigations of wing and wing-fuselage configurations at two representative tail heights and to compare these results with theoretical estimations made in subsonic and supersonic Mach number range."

From Introduction: "First, an analysis of loads transmitted to the hub by balanced blades will be given. In the second section, the additional loads transmitted to the hub in a direction normal to the plane of rotation of the blades by imbalances in a rotor are derived. In the entire analysis, the results are given in terms of the forces transmitted to the hub by a single rotating helicopter blade in flight, and these are regarded as known or given."

From Introduction: "The purpose of this report is to treat analytically heat addition heat addition to a divergent stream with initially sonic flow and to employ the results thus obtained in evaluating the effect of delayed combustion on convergent-divergent nozzle performance."

"Slender-body theory is used in conjunction with late theory to analyze the static aeroelastic-divergence behavior of low-aspect-ratio rectangular wings of constant thickness when chordwise deformations are considered. In the analysis, the spanwise variation of the deflection is restricted to a parabola but the chordwise variation is allowed complete freedom. Results show the variation of the divergence speed and mode shape with the aspect ratio" (p. 1).

From Introduction: "In the turbulent case, however, the results of the various analyses disagree markedly because of the different assumptions made by various authors. These analyses are reviewed in references 1 to 3. The analysis is extended to flow and heat transfer in a boundary layer at high Mach numbers in this paper. (Some preliminary results were presented in ref. 11.)"

From Introduction: "In rounded-approach nozzles with discharge coefficients close to unity, the frictional effects are concentrated in the boundary layer. A method of obtaining an analytical relation among the discharge coefficient, Reynolds number, and the nozzle geometry by utilization of elementary boundary-layer theory is presented herein."

The generalized shock-expansion method is applied to obtain solutions to the flow field about pointed bodies of revolution at high supersonic airspeeds and small angles of attack. Simple explicit expressions are obtained for the surface Mach numbers and surface pressures in the special case of slender bodies. In the case of inclined cones, algebraic solutions are obtained defining the entire flow field. Experimental pressure-distribution data for cones and ogives at Mach numbers from 3 to 5 are included. (author).

"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 numerical solutions of quantities appearing in the Karman momentum equation for the development of a turbulent boundary layer in plane and in radial compressible flows along thermally insulted surfaces in tabular form for a rnage of Mach numbers from 0.100 to 10. Through use of the tables, approximate calculation of boundary-layer growth is reduced to routine arithmetic computation.

Note presenting a method for the design and analysis of two-dimensional subsonic-flow passages with isentropic nonviscous flow. The method is based on the relation between the pressure change across a stream tube and the centrifugal force resulting from the curvature of the flow. In an example, the method was applied to the design of an expanding elbow at each of two Mach numbers.

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.

Note presenting internal-pressure tests made on aluminum-alloy unstiffened cylinders with precut slits to study the effect of slit length and curvature on the hoop stress developed at the bursting pressure. The results are predicted with good accuracy by applying a curvature correction to the method presented in a previous report for computing the strength of flat plates with cracks.

Report presenting the results of some sample calculations for the bending-aileron and torsion-aileron flutter of an idealized wing-aileron system for several values of Mach number in supersonic flow and some subsonic Mach numbers. The results are preliminary but may provide some knowledge of the influence of variations in certain parameters and to indicate some of the differences in the trends at high and low speeds.

Report presenting the rate equation for the dissociation of air, based on simple-collision theory, and the numerical values of the factors that enter it. The rate equation and conservation equations for a flowing dissociating gas are solved for the conditions behind normal shock waves at Mach numbers of 10, 12, and 14. Results regarding the adjustment of translation, rotation, and vibration and adjustment of dissociation are provided.

A series of papers describing a system that will automatically record as many as 300 pressures, 200 voltages, and 24 frequencies in as little as 30 seconds to an accuracy of 0.15 percent or better of full-scale range. The information is able to be used in any high-speed, general-purpose digital computer. The computer will accept the encoded data produced by the recording system and automatically calibrates it, takes averages, forms ratios, and does terminal calculations such as mass flow, momentum, distortion numbers, drag coefficients, thrust, specific fuel consumption, and efficiency.

Report presenting charts that permit the determination of enthalpy change for various processes regarding the thermodynamic data of gas properties. Some examples using the charts to solve problems are provided.