Report presenting charts for estimating the effects of variations in short-period stability characteristics of a rigid airplane on its root-mean-square vertical-acceleration and pitch-angle response to continuous atmospheric turbulence. A comparison of the root-mean-square vertical-acceleration response of an airplane free to be disturbed in vertical and pitching motion with that of an airplane free to be disturbed only in vertical motion indicates that the responses are similar for a nearly critically damped airplane.

A simple and practical method for evaluating the onset of permanent buckling in plates in the presence of combined thermal and compressive load stresses is outlined. A particular application of the method shows reasonable agreement with tests of 17-7 PH stainless-steel square tubes. The results indicate that the compressive load stress which the plate can support at the onset of permanent buckling is substantially reduced as the temperature difference of the plate and adjoining members increases.

Note presenting the equations for development of the compressible laminar boundary layer over a yawed infinite cylinder. The results indicate that the effect of yaw on the heat-transfer coefficient at the stagnation line depends markedly on the free-stream Mach number.

Report presenting lightweight design concepts, which were developed and tested in a full-scale turbine wheel with a tip diameter of 34.3 inches and a tip speed of 1190 feet per second. It consisted of a rotor of two thin alloy disks attached with spacers and bolts and hollow turbine blades. Testing indicated that it would be particularly applicable to an expendable missile engine.

"Thermal stresses, which may result from transient heating, can cause changes in the effective stiffness of wing structures. Some effects of this change in stiffness were investigated experimentally by radiantly heating three types of simple wing structures: a uniform plate, a solid double-wedge section, and a circular-arc multiweb-wing section. Changes in stiffness were determined by measuring the changes in natural frequency of vibration during transient heating. Some comparisons are made between theoretical calculations and the measured data" (p. 1).

Note presenting an investigation conducted in the high-speed 7- by 10-foot tunnel to determine the effects of varying the horizontal-tail position relative to the wing chord plane on the aerodynamic characteristics in pitch of a general research model having a 45 degree sweptback wing of aspect ratio 4, taper ratio 0.30, and NACA 65A006 airfoil sections. The investigation also included the effects of a wing modification consisting of a full-span leading-edge flap deflected 6 degrees and an outboard partial-span chord-extension.

Note presenting results of several experimental investigations which indicate the effects of rapid heating on the bending strength of multiweb beams and ring-stiffened cylinders. Thermal stresses are shown to reduce the bending load carried at buckling by both beams and cylinders.

Note presenting the incompressible boundary-layer theory of Truckenbrodt extended using a modified Stewartson-type transformation to include compressible boundary-layer development over insulated surfaces. The method is applicable to two-dimensional and axisymmetric, laminar and turbulent boundary layer, and accounts for the pressure gradient along the wall for both compressible and incompressible flow. Some experimental measurements of the boundary layer on small axisymmetric bodies on the wall of a supersonic wind tunnel compared with theoretical predictions.

A study of the effect of induction-vacuum-melting procedure on the high-temperature properties of a titanium-and-aluminum-hardened nickel-base alloy revealed that a major variable was the type of ceramic used as a crucible. Reactions between the melt and magnesia or zirconia crucibles apparently increased high-temperature properties by introducing small amounts of boron or zirconium into the melts. Heats melted in alumina crucibles had relatively low rupture life and ductility at 1,600 F and cracked during hot-working as a result of deriving no boron or zirconium from the crucible.

Report presenting a solution to the unsteady two-dimensional laminar boundary-layer flow inside centered expansion waves and behind both centered expansion waves and shock waves using an extension of the Karman-Pohlhausen method. The Prandtl unsteady-boundary-layer equations are also integrated normal to the surface bounding the flow and are transformed into a conical coordinate system. The solution to the two-dimensional unsteady laminar boundary layer existing at all points in an air-air shock tube is obtained using the method.

Results of an investigation at low speeds to determine the gust-alleviation capabilities (reduction in lift-curve slope) of spoilers and deflectors on a 35 degree swept-wing model of high aspect ratio and on a 1/4-scale model of the X-5 airplane with 35 degree swept wings indicate that deflector and spoiler-deflector types of controls can be designed to provide considerable gust alleviation for a swept-wing airplane while still maintaining stability and control.

Report presenting an investigation in the high-speed 7- by 10-foot tunnel using the transonic bump method to determine the gust-alleviation capabilities of spoilers and deflectors when mounted on a 35 degree swept semispan wing with NACA 65A006 airfoil sections. Testing was conducted over a range of Mach numbers and angles of attack.

Note presenting an investigation of a straight outer-wall annular diffuser with a center-body length of one-half the outer-body diameter and an area ratio of 1.9:1 for mean inlet flow angles of 0 and 19.5 degrees in order to determine the effect of area suction applied on the inner wall. The entrance shape, number, and location of the openings through which the air was removed were varied. Results regarding inlet flow conditions, visual-flow observations with axial flow, performance with axial flow, and performance with whirling flow are provided.

A brief review is presented of the basic methods of gust alleviation. Some results obtained in flight tests of a gust-alleviation system are included.

Note presenting a consideration of the equations of motion and energy for the laminar boundary layer flow in an expansion wave of finite width moving into undisturbed fluid, such as in a shock tube. Solutions in the form of infinite power series for velocity and local enthalpy functions were indicated and the first three terms of each series were numerically evaluated. Results regarding numerical information, a discussion of the results, a comparison with the solution of the zero-thickness expansion wave, and singularities in the flow field are provided.

"Separate investigations have dealt with the critical crack length of flat sheets or of unstiffened cylinders and with the type of rupture experienced by stiffened cylinders. These investigations are correlated, supplemented by new tests, and combined into a uniform scheme for predicting critical crack length and type of rupture in stiffened pressurized cylinders" (p. 1).

"A theoretical study is made of the influence of tire hysteresis effects on the rolling motion and wheel shimmy of landing gears. The results of this study indicate that hysteresis forces and moments have a noticeable secondary influence on the landing-gear rolling behavior. Comparisons of the available experimental data with the corresponding theoretical predictions provide a fair confirmation of the theory" (p. 1).

"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).

Note presenting the results of some theoretical and experimental investigations of delta-wing vibrations. Experimental nodal-line patterns and frequencies for a 60 degree thick-skin delta wing are shown. Comparisons of the different investigations have shown that the idealized-strucutre type of method as proposed by Levy gives excellent results for thin-skin wings provided that corrections are made for the effects of transverse shear.

Report presenting an analysis to ascertain the feasibility of using the device to produce high-temperature air. The production of high temperature is associated with the leakage of the hot outlet air through the tip clearance to the inlet and the subsequent mixing with the supply air. The calculated performance of the unit is very sensitive to the assumed value of Stanton number.

"The influence of joint conductivity and internal radiation on temperature distribution and thermal stresses has been discussed. Joints of poor conductivity can occur in normal fabrication procedure and greatly alter temperature distributions and increase thermal stresses. On the other hand, internal radiation tends to make the temperature distributions more uniform and thereby relieves thermal stress" (p. 1).

This paper presents a description of a simple air-jet shaker. Its force can be calibrated statically and appears to be constant with frequency. It is relatively easy to use, and it has essentially massless characteristics. This shaker is applied to define the unstable branch of a frequency-response curve obtained for a nonlinear spring with a single degree of freedom.

From Introduction: "The purpose of this report is to present the results of an analytical investigation of the engine characteristics of two-spool engines with high over-all compressor pressure ratio (12.0 at design). Some of the turbine design problems encountered in a single-spool engine with current compressor pressure ratio (7.32 at design) were investigated in reference 1. The investigation was extended in reference 2 to cover the effect of mode of engine operation on the turbine design requirements and engine performance for a single-spool engine with current compressor pressure ratio."

"Flat 2024-T3 aluminum panels measuring 11 inches by 13 inches were tested in the near noise fields of a 4-inch air jet and turbojet engine. The stresses which were developed in the panels are compared with those calculated by generalized harmonic analysis. The calculated and measured stresses were found to be in good agreement. In order to make the stress calculations, supplementary data relating to the transfer characteristics, damping, and static response of flat and curved panels under periodic loading are necessary and were determined experimentally. In addition, an appendix containing detailed data on the near pressure field of the turbojet engine is included" (p. 703).