Report presenting an analysis of the performance of a composite engine consisting of a reciprocating spark-ignition engine, two superchargers, a blowdown turbine, and a steady-flow turbine. The performance of the configuration was analyzed in order to determine the suitability and cost of design compromises when the size of turbines and superchargers and all gear ratios are assumed fixed. Results regarding the variable-component system, fixed-component system, and auxiliary-propeller system are provided.

Note presenting equations derived for the wave drag of sweptback tapered wings with thin symmetrical double-wedge sections at zero lift. Calculations of section wave-drag distributions and wing wave drag are presented for families of tapered plan forms. Results regarding section wave drag and wing wave drag are provided.

Report presenting a theoretical investigation of the supersonic wave drag at zero lift of a series of untapered sweptback wings with thin symmetrical biconvex parabolic-arc sections. The investigation was extended to include Mach numbers which bring the Mach line behind the wing leading edge and also to include wings of rectangular plan form.

Report presenting calculations to determine the influence of changes in temperature distribution and elastic material properties on calculated elastic stresses for a typical gas-turbine disk. Severe temperature gradients caused thermal stresses of sufficient magnitude to reduce the operating safety of the disk.

Note presenting a method for determining, by step-by-step integration, the trajectories of water drops around any body in two-dimensional flow for which the streamline velocity components are known or can be computed. The equations are presented in general form and then, to illustrate the procedure, water-drop trajectories are calculated about a 12-percent-thick symmetrical Joukowski profile chosen to simulate an NACA 0012 section. The method provides a means for the relatively rapid calculation of the trajectory of a single drop without the utilization of a differential analyzer.

Note presenting measurements of the vertical distribution of liquid water concentration and drop size in winter stratus clouds in the absence of significant cyclonic or frontal activity. The observations indicate that the clouds are formed by turbulent mixing of the lower layers of the atmosphere, resulting in a region of constant specific humidity and adiabatic lapse rates. Calculations based on the observations were used to construct a graph that gives the liquid water concentration in terms of the temperature at the cloud base and the height above the base.

An investigation was conducted to furnish data on the effect of tab balance on tab and control-surface characteristics. The airfoil tested had a modified NACA 65(1)-012 contour with a plain flap having a chord equal to 25 percent of the wing chord and with a tab having a chord equal to 25 percent of the flap chord and having several nose shapes and overhang lengths. The results of the investigation indicated that, in general, tab balance affected tab hinge-moment characteristics in much the same manner that flap balance affects flap hinge-moment characteristics. A moderate amount of tab balance did not seem to have any adverse effect on flap hinge-moment characteristics.

"Following the law of stress adopted in the Navier-Stokes equations, the configuration of the viscous flow in planes at right angles to the axis of an infinite cylinder is found to be independent of the axial motion of the cylinder. In the limiting case of a yawed or swept wing of very high aspect ratio, certain boundary-layer and separation phenomena are thus determined independently by the crosswise component of velocity" (p. 1).

An introduction to the problem of determining the fundamental limitations on the performance possibilities of rocket-powered aircraft is presented. Previous material on the subject is reviewed and given in condensed form along with supplementary analyses. Some of the problems discussed are: 1) limiting velocity of a rocket projectile; 2) limiting velocity of a rocket jet; 3) jet efficiency; 4) nozzle characteristics; 5) maximum attainable altitudes; 6) ranges. Formulas are presented relating the performance of a rocket-powered aircraft to basic weight and nozzle dimensional parameters. The use of these formulas is illustrated by their application to the special case of a nonlifting rocket projectile.

"A resume is given of an investigation of the influence of plastic deformation and of annealing temperature on the tensile and shear elastic properties of high strength nonferrous metals and stainless steels in the form of rods and tubes. The data were obtained from earlier technical reports and notes, and from unpublished work in this investigation. There are also included data obtained from published and unpublished work performed on an independent investigation" (p. 1).

Report presenting a method of predicting the dynamic response of airplane wings to gusts by considering only the fundamental mode of bending along with the results of model tests to evaluate the method. Results regarding experimental results and associated calculations, limitations of calculations, and results calculated for effect of change of certain parameters are provided.

Report presenting an equation for calculating the heat flow required from the surface of an internally heated windshield in order to prevent ice accretions during flight in specified icing conditions. Results regarding the internally heated windshield characteristics, external discharge windshields, and prediction of heating requirements for both types of windshields are provided.

"In the present paper, under the same lineaeizing assumptions as are made in the derivation in reference 1 but with the explicit consideration and simplification of the form of the wake extending from the rear of the airfoil, the methods of Theodorsen (reference 2) have been extended to obtain the forces on the airfoil not only at a fixed angle of attack but also in arbitrary motion" (p. 1).

From Summary: "These properties compare favorably with those of the strongest similar alloys previously investigated. However, compared with a 60Cr-25Fe-15Mo alloy, the three cobalt-chronium-nickel cast alloys are inferior. A correlation of NACA and OSRD (Project NRC-8) data is presented, showing the variation of rupture strengths with temperature in the range of 1350^o to 2000^o for alloys."