Report presenting a study of wear and sliding friction properties of a number of nickel alloys operating against hardened SAE 52100 steel. The alloys were cast beryllium nickel, heat-treated beryllium nickel, cast Inconel, Nimonic 80, Inconel X, Refractalloy 26, and Discaloy. Results regarding the wear of unlubricated surfaces, friction of lubricated surfaces, x-ray diffraction study of wear debris, and the practical significance are provided.

From Summary: "A Langley low-turbulence wind-tunnel investigation of a porous NACA 64A010 airfoil section has been made to determine the effectiveness of area suction in maintaining full-chord laminar flow behind finite disturbances and at angles of attacks other than 0 degrees. Aero suction resulted in only a small increase in the size of a finite disturbance required to cause premature boundary-layer transition as compared with that for the airfoil without suction. Combined wake and suction drags lower than the drag of the plain airfoil were obtained through a range of low lift coefficient by the use of area suction."

Report presenting a study of several aspects of transonic flow around the forward portions of wedge profiles by means of interferometry. Measurements were made of the two kinds of flow pattern that occur at the leading edge of a wedge at an angle of attack. Results regarding the flow at leading edge, flow around the corner, method of characteristics, drag coefficient of the wedge at 14.5 degree semiangle, and conditions at bases of shock waves are provided.

From Introduction: "The problem of free-convection flow as produced by a body force about a flat plate in the direction of the body force was studied at the NACA Lewis laboratory and is treated in a formal and more general manner herein. The method used is somewhat similar to that used in reference 4 wherein consideration was given to the free-convection flow at high Grashof numbers in a horizontal cylinder which had a variable surface-temperature distribution. In addition, the numerical solutions of references 2 and 3 are herein extended to cover a more complete range of variables."

Report presenting an investigation of the accuracy of the result obtained in a fundamental paper by Kantrowitz that a small short-time lowering of the back pressure in steady, shock-free, transonic diffuser flow causes a stationary or trapped shock to form near the critical shock channel throat.

Report presenting an investigation to provide a basis for the design of combination probes intended to survey the static and total pressure and direction of flow with special reference to subsonic turbo-machine testing. Static-pressure probes, yaw-element probes, claw-type yaw probes, and combination probes were tested in an 8-inch-diameter calibration tunnel. The factors that determine the sensitivity of claw-type yaw probes were determined from this test.

Report presenting an experimental investigation of the effect of oil viscosity on bearing operation characteristics using a 75-millimeter-bore cylindrical-roller inner-race-riding cage-type bearing. Results regarding DN value, oil flow, viscosity, the combination of DN and oil flow, oil inlet temperature, and improvements to cooling correlation theory are provided.

Report presenting a description of a device for adapting rotating-beam fatigue testing machines for tests in which the amplitude of stress is continuously varied. Testing was conducted on 24S-T aluminum-alloy specimens subjected to stresses with amplitudes varying according to sinusoidal and exponential functions.

Note presenting a theoretical solution obtained for the problem of the compressive buckling of flat rectangular Metalite type sandwich plates with simply supported loaded edges and clamped unloaded edges. The solution is based on the general small-deflection theory for flat sandwich plates developed in a previous NACA report. Results regarding the stability criterion and buckling curves, correction for plasticity, and a comparison with theoretical results are provided.

"Equations expressing the heat transfer and evaporation from wetted surfaces during ice prevention have been simplified and regrouped to permit solutions by simple graphical means. Working charts for quick and accurate anti-icing calculations are also included" (p. 1).

Note presenting several approximate methods for calculating lift distributions at subsonic speeds, which are combined and extended to form a simple step-by-step procedure for calculating symmetric and antisymmetric lift distributions for arbitrary angle-of-attack conditions on swept and unswept wings. The results obtained by the method compare favorably with those obtained by more time-consuming theories.

From Summary: "Results of an analytical and a sea-level experimental investigation of a turbojet engine with proportional speed control are presented."

Report presenting a solution for three-dimensional, incompressible, non-viscous, potential flow in a rotating impeller passage with zero through flow. The solution is obtained for a conventional impeller with straight blades but with the inducer vanes removed and the impeller blades extended upstream parallel to the axis of the impeller.

Note presenting testing of the gliding of one metal crystal with respect to another, along their mutual grain boundary, during high-temperature creep tests conducted with bicrystals of pure aluminum. Stresses of from 1 to 100 psi and temperatures from 200 to 650 degrees Celsius were employed. Results regarding grain boundary glide rate, influence of orientation difference between grains, influence of temperature, influence of applied stress, structure of the operated grain boundary, and structural changes within grains are provided.

"An investigation has been made of the elastic stability of an idealized box beam with longitudinally stiffened covers connected by posts and subjected to end moments and axial loads. Stability criterions which give the axial stiffness of the posts required to achieve desired stress values in the box-beam covers are derived" (p. 1).

Report presenting flight testing of a commercially available flight indicator that combines heading, bank-angle, fuselage-pitch-attitude, and potentially altitude and radio-aid information in order to determine its suitability for helicopter instrument flying. The indicator was installed in the instrument panel of a helicopter meant for blind flying and was evaluated by performing prescribed maneuvers with conventional instruments and the combined-signal flight indicator. The indicator was found to result in less fatigue to the pilot and to require less concentration.

Measurements of temperature variations in the atmosphere near the tropopause over land in the vicinity of Langley Field, Va., are presented. This investigation was made for the purpose of obtaining information on the accuracy of the temperature method(NACA TN 2046) of airspeed calibration over the range of Mach number from 0.6 to .08. The temperature surveys and the description of a specially designed thermometer are also presented.

Report presenting an analysis of the gust response of an airplane with degrees of freedom of vertical motion and wing bending flexibility and basic parameters. The method of determining a gust causing a known response is indicated and a procedure is given for determining the response of an airplane directly from the known response of another airplane by eliminating the common gust condition.

A short-bearing approximation of pressure distribution in the oil film is presented which is an extension of the pressure-distribution function of Michell and Cardullo and includes end-leakage effects. Equations giving applied load, attitude angle, location and magnitude of peak film pressure, friction, and required oil flow rate as functions of the eccentricity ratio are also given. The capacity number, a basic non dimensional quantity resulting from this analysis is the product of the Sommerfeld number and the square of the length-diameter ratio.

Note presenting an investigation of the accuracy and range of applicability of the linearized theory, second-order theory, tangent-cone method, conical-shock-expansion theory, and Newtonian theory for predicting pressure distributions on pointed bodies of revolution at zero angle of attack. Three shapes, cone, ogive, and a modified optimum body, are investigated over a wide range of fineness ratios and Mach numbers. The results indicated that for most combinations of fineness ratio and Mach number, one of the approximate methods will give reasonable results.

Note presenting a method for the determination of the time lag in pressure measuring systems incorporating capillaries. The method can be used to select, design, or redesign a pressure measuring system to meet the time requirements of a particular installation. Experimental data are shown and a step-by-step sample application is presented.

Report presenting the use of the similarity law for steady hypersonic flow about slender shapes as extended to nonsteady flows. The aerodynamic forces and moments are correlated for related shapes by means of this law. The motions of related bodies in free flight could be correlated using the hypersonic similarity parameters and additional parameters relating the inertial properties of the bodies and air densities.

Note describing a method of engine simulation involving the use of an electronic analog computer in the simulation of controlled aircraft-engine performance. The equations used in developing the method of simulating the dynamics of gas-turbine engines are derived in general form from engine functional relations.

"Two methods of using the concept of linearized characteristics are derived for the one-dimensional unsteady flow in a tube that is rotated about an axis perpendicular to the axis of the tube. One of the methods correponds to that used by Ferri in his basic work on the subject. Solutions are made by both methods for boundary conditions that allow analytic solutions" (p. 1).