Two-dimensional tests were made of an NACA 0006 airfoil with area suction applied to a porous region on a 0.3-chord trailing-edge flap deflected 50 degrees. The lift with suction approached the value computed from thin-airfoil theory. The lift gains and suction quantity requirements were unaffected by the perforation patterns of the surface over a wide range of hole sizes and spacings.

From Summary: "An investigation was made in the NACA 7 by 10 foot wind tunnel to find the increase in maximum lift coefficient which could be obtained by providing a model wing with both a Fowler trailing-edge extension flap and a Handley Page type leading-edge slot. A conventional Handley page slot proportioned to operate on the plain wing without a flap gave but a slight increase with the flap; so a special form of slot was developed to work more effectively with the flap. With the best combined arrangement the maximum lift coefficient based on the original area was increased from 3.17, for the Fowler wing, to 3.62."

Report presenting a theoretical investigation to study the effects of systematic changes in configuration of a representative airframe on the center-of-pressure travel due to changes in angle of attack and Mach number. The airframe was an unbanked canard missile configuration with low-aspect-ratio coplanar wing and tail surfaces of triangular plan form.

"A theoretical analysis is given for the stresses and deflections of a square plate with clamped edges under normal pressure producing large deflections. Values of the bending stress and membrane stress at the center of the plate and at the midpoint of the edge are given for center deflections up to 1.9 times the plate thickness. The shape of the deflected surface is given for low pressures and for the highest pressure considered" (p. 1).

Note presenting an experimental investigation conducted to determine the characteristics of a 40 degree cone for use in the measurement of Mach number, total pressure, and flow angles. The cone had a total-pressure orifice at the apex and four equally spaced static-pressure orifices on the surface and pressure measurements were taken at a range of angles of pitch, Mach numbers, and Reynolds numbers. Results regarding cone pressure distribution, determination of Mach number, determination of total pressure, and determination of flow angles are provided.

Report presenting the method and advantages of matrix algebra in setting up the geometric aspects of problems of airplane motion. The paper is divided into two parts. The first is about the aspects of matrix algebra required for use in orthogonal transformations and the other shows how to use orthogonal transformations in matrix form by applying them in several examples.

Note presenting an analysis which predicts the skin-friction and heat-transfer characteristics of a compressible, laminar boundary layer on a solid flat plate preceded by a porous section that is transpiration cooled. The analysis is restricted to a Prandtl number of unity and linear variation of viscosity with temperature. Results regarding a comparison of polynomial and exact velocity distribution, skin friction, heat transfer, and some practical implications of results are provided.

Report presenting a low-turbulence wind-tunnel investigation of an NACA 64A010 airfoil with a porous surface to determine the reduction in section total-drag coefficient that can be obtained at large Reynolds numbers by using area suction. While previous testing has been reported on, the focus of this paper is primarily the results of additional tests of the same airfoil model equipped with a porous skin of lower porosity.

"A single chart has been prepared that simplifies the calculation of the thermodynamic properties of air, various octene-air mixtures, and mixtures of those with their products of combustion at all temperatures below which chemical dissociation becomes unimportant. The chart is based on the use of 1 pound mol of mixture, and examples of its use are given in the form of the calculation of a turbocompressor power plant and a supercharged Otto engine cycle" (p. 1).

Report presenting flame speeds based on the inner edge of the shadow cast by the laminar Bunsen cone for methane-air and ethylene-air mixtures as functions of composition at initial mixture temperatures ranging from 34 degrees to 344 degrees Celsius. The data showed that flame speed increased with temperature at an increasing rate, as did similar data reported earlier for propane and air.

"A theoretical study has been made of the reduction in downwash and upward displacement of the wake in the presence of the ground, and some verification of the theory has been obtained by means of air-flow measurements made with a ground-board and image-wing combination. Methods are given for estimating the effects and numerous examples are included to illustrate the nature of these effects and to show their order of magnitude" (p. 1).

Note presenting testing of bonding processes evaluated by tension tests on sandwich specimens of 1-inch aluminum cubes bonded to a resin-impregnated paper honeycomb core. 6 of the 14 processes gave good-quality bonds which had average strengths of more than 350 psi or more than 75-percent failure in the core when tested at two different temperatures.

Numerical methods have been developed for obtaining the steady, adiabatic flow field of a frictionless, perfect gas about arbitrary two-dimensional bodies. The solutions include the subsonic velocity regions, the supersonic velocity regions, and the transition compression shocks, if required. Furthermore, the rotational motion and entropy changes following shocks are taken into account. Extensive use is made of the relaxation method. In this report the details of the methods of solution are emphasized so as to permit others to solve similar problems. Solutions already obtained are mentioned only by way of illustrating the possibilities of the methods described. The methods can be applied directly to wind tunnel and free air tests of arbitrary airfoil shapes at subsonic, sonic, and supersonic speeds.

Note presenting the use of the hodograph method to investigate the problem of flow of a compressible fluid past a body with subsonic flow at infinity. Explicit formulas for numerical calculations are given for the flow about a body, such as an elliptical cylinder, and for the periodic flow such as would exist over a wavy surface.

Report presenting a study of the two-dimensional flow of a frictionless, adiabatic, perfect gas inside of a two-dimensional hyperbolic nozzle by using numerical methods.

From Summary: "The presence of radomes and instruments that are sensitive to water films or ice formations in the nose section of all-weather aircraft and missiles necessitates a knowledge of the droplet impingement characteristics of bodies of revolution. Because it is possible to approximate many of these bodies with an ellipsoid of revolution, droplet trajectories about an ellipsoid of revolution with a fineness ratio of 10 were computed for incompressible axisymmetric air flow. From the computed droplet trajectories, the following impingement characteristics of the ellipsoid surface were obtained and are presented in terms of dimensionless parameters: (1) total rate of water impingement, (2) extent of droplet impingement zone, and (3) local rate of water impingement."

Note presenting wind-tunnel tests to ascertain the total-pressure recovery of a circular nose inlet utilizing various shapes of inlet lips. The tests were conducted at a free-stream Mach number of 0.237 with inlet flows ranging from low values to choking and at angles of attack from 0 to 25 degrees.

Report presenting testing of a flat-bottom V-step model with a beam loading of 4.6 subjected to fixed-trim impacts in smooth water. Testing occurred at three different trim angles and a range of initial flight-path angles. Data were obtained as time histories of draft, vertical velocity, and vertical acceleration. The results are presented as plots of nondimensional lift, draft, vertical velocity, and time against flight-path angle at contact.

"The results of an experimental investigation of the strength of plane diagonal-tension webs with ratios of web depth to web thickness of about 60 are presented. An analysis of the beam indicated that the methods of strength analysis presented in NACA TN 2661 are applicable to beams with flanges symmetrically arranged with respect to the web if the portal-frame effect is taken into account" (p. 1).

From Summary: "The principles involved in the operation of several types of stall-warning devices are described and conditions under which difficulty may be experienced are pointed out. In the discussion, stall-warning devices are grouped as special stall-sensing devices and angle-of-attack-sensing devices. Methods of transmitting the warning to the pilot are also discussed. Some specific examples of stall-warning devices are illustrated and described."

Note presenting graphs for rapid evaluation of air-induction systems from considerations of their aerodynamic-performance parameters in combination with power-plant characteristics. The graphs cover the range of supersonic Mach numbers up to 3.0. The illustrative examples indicate that the inlet area required for optimum performance must change with altitude at a fixed Mach number as well as with Mach number at a fixed altitude.

Report presenting a linearized theoretical analysis made to determine minimum-wave-drag airfoil sections for arrow wings having the same airfoil sections at all spanwise sections. Numerical computations of the airfoil shape and wing wave drag were performed for a delta wing and an arrow wing with a ratio of the tangent of the trailing-edge sweep angle to the tangent of the leading-edge sweep angle of 0.4.

Report presenting a low-speed investigation in the stability tunnel to determine and improve, if possible, the directional stability characteristics of two tandem helicopter fuselages, one representing a helicopter with overlapping rotors and the other a helicopter with nonoverlapping rotors. Results regarding the presentation of data, directional stability of overlap-type fuselage, and directional stability of nonoverlap-type fuselage are provided.

Note presenting the results of buckling tests of long square tubes loaded in compression, torsion, and combined compression and torsion and a comparison with theoretical compression and shear buckling curves and with theoretical interaction curves for the buckling of simply supported flat plates. Results regarding the pure compression and pure torsion buckling and combined compression and torsion buckling are provided.