Memorandum describing an investigation using two airplanes, an F6F-3 and F-86A, each fitted with servo equipment for varying in flight the lateral and directional stability and handling characteristics, which have been flown by test pilots to simulate the predicted dynamic behavior of six prototype airplanes. The methods of simulation and the types and ranges of variables considered are presented and the results of the individual programs are discussed.

"A study has been made of a flare-cylinder configuration to investigate its feasibility as a reentry body of an intermediate range ballistic missile. Factors considered were heating, weight, stability, and impact velocity. A series of trajectories covering the possible range of weight-drag ratios were computed for simple truncated nose shapes of varying pointedness, and hence varying weight-drag ratios" (p. 1).

An investigation was conducted on a 35 deg swept-wing fighter airplane to determine the effects of several blunt-trailing-edge modifications to the wing and tail on the high-speed stability and control characteristics and tracking performance. The results indicated significant improvement in the pitch-up characteristics for the blunt-aileron configuration at Mach numbers around 0.90. As a result of increased effectiveness of the blunt-trailing-edge aileron, the roll-off, customarily experienced with the unmodified airplane in wings-level flight between Mach numbers of about 0.9 and 1.0 was eliminated, The results also indicated that the increased effectiveness of the blunt aileron more than offset the large associated aileron hinge moment, resulting in significant improvement in the rolling performance at Mach numbers between 0.85 and 1.0. It appeared from these results that the tracking performance with the blunt-aileron configuration in the pitch-up and buffeting flight region at high Mach numbers was considerably improved over that of the unmodified airplane; however, the tracking errors of 8 to 15 mils were definitely unsatisfactory. A drag increment of about O.OOl5 due to the blunt ailerons was noted at Mach numbers to about 0.85. The drag increment was 0 at Mach numbers above 0.90.

Report presenting an investigation at Mach numbers of 1.61 and 2.01 to determine the pressure distributions for a series of 20 controls on a 60 degree delta wing. Tests occurred at a range of angles of attack and control deflections. Results regarding basic pressure distributions, comparison of experimental and theoretical results, and experimental comparisons are provided.

Report presenting an investigation of the use of aerodynamic and mechanical devices for improving the response of guided missiles. An analysis indicates that the use of free-floating flaps and spring-mounted control surfaces should be able to increase maneuverability to the point that electronic automatic stabilization and gain-adjusting devices can be eliminated.

Report presenting an investigation conducted with trimethyl borate azeotrope and pentaborane fuels in a turbojet combustor. The primary purposes of the study were to determine the effect of boron oxide deposits on the turbine-nozzle area, combustor pressure loss, temperature distribution, and combustion efficiency. Three distinct boron deposit patterns were noted in the investigation.

Report presenting an investigation of the blades of an experimental two-blade jet-driven helicopter when subject to a condition of near resonance between the frequencies of the first elastic bending mode of the blades and third harmonic component of the aerodynamic loading that results in high bending strains in normal flight conditions. Various changes in design configuration on the blade bending strains were explored. Results regarding the preliminary studies, effects of variation in flight conditions and blade configuration, and harmonic analysis are provided.

Report presenting a partly linearized solution of plastic deformation of a rotating disk based on the deformation theory of plasticity and considering finite strains. The method can be used to investigate the general plastic behavior of a rotating disk.

"A theoretical discussion of the application of blade boundary-layer control to increase the efficiency and the stage pressure ratio and to improve off-design performance of turbomachines is presented. A method based on the potential flow of a compressible fluid is developed for designing suction, or ejection, slotted blades having a prescribed velocity distribution along the blade and in the slot. The effect of the boundary layer on the design of the slot and the effect of ejecting gas at stagnation pressures and temperatures different from free-stream values are discussed" (p. 1).

From Summary: "Values of the downwash of a horseshoe vortex in compressible flow are presented in the form of charts and tables. The use of the charts and tables in the calculations of the downwash of wings of arbitrary plan form is discussed. The results of a few calculations are compared with experimental results."

Report presenting an investigation to determine the floating characteristics of full-length plain and horn-balanced rudders during rotary tests at spinning attitudes on a scale model of a typical low-wing personal-owner airplane. The investigation included the determination of the effects of the horizontal tail and the wing on the rudder floating characteristics.

Report presenting data for turbulent-velocity-fluctuation components and mean-velocity distributions measured in the subsonic jet issuing from a pipe in which a fully developed turbulent flow was established. Axial and radial components of the fluctuation velocities were examined as functions of Reynolds number and position in the jet.

"The present report covers a series of torsional tests on stiffened D-tubes of alclad 24S-T3 aluminum alloy having a cross section similar to the NACA 0012 airfoil section and a closing web at 30 percent of the chord. The stiffeners consisted of ribs and stringers. An average-strength chart has been developed for this type of structure that takes into account the skin thickness, rib spacing, and stringer spacing. This chart may also be used for unstiffened D-tubes" (p. 1).

Note presenting an account of explicit solutions in terms of Mathieu functions of the problem of two-dimensional subsonic compressible flow past oscillating airfoils. The results are applied to the calculation of three-dimensional corrections for the two-dimensional theory and the effect of the incorporation of the three-dimensional effects on the Mathieu function solution of the two-dimensional problem is shown.

Note presenting an analysis of the problem of two-dimensional flow behind a curved stationary shock wave. The method assumes a given shock-wave shape, which automatically determines certain initial conditions on flow variables, and flow-pattern, including any body shape, follows from initial conditions.

Report presenting an investigation in the high-speed 7- by 10-foot tunnel to determine some effects of tail height and wing plan form on the static longitudinal stability characteristics of a complete, small-scale model at high subsonic speeds. It had both a low-tail and high-tail position. Results regarding the lift and drag characteristics and longitudinal stability characteristics are provided.

Report presenting a description of a new blade series designed to operate at near choking inlet Mach numbers and to have near maximum critical Mach numbers by employing high aerodynamic loading of the profiles in the leading-edge region. Results regarding aerodynamic characteristics and prediction of high-speed performance are provided.

Note presenting an experimental investigation of the heat-loss characteristics of heated fine wires suitable for use as anemometers in turbulence research. The effects of each of the several variables on the heat-loss characteristics of both normally oriented and swept wires were measured. The temperature-loading effects were found to cause large sensitivity differences between constant-temperature and constant-current operation.

From Summary: "Charts are developed for the analysis of flow in a whirling constant-diameter duct. These charts permit the determination of the duct-exit Mach number, or the Mach number at any point along the duct, for practical ranges of duct-inlet Mach number, duct-tip Mach number, friction factor, ratio of ambient temperature to duct-flow total temperature, ratio of duct-tip radius to duct hydraulic diameter, and heat conductivity through the duct wall and surrounding material. The method of using the charts is illustrated through the computation of a sample problem."

Report presenting calculations of the lift and moment responses to penetration of sharp-edged traveling gusts for wings in incompressible and supersonic two-dimensional flow, for wide delta and rectangular wings in supersonic flow, and for very narrow delta wings. The results of the calculations indicate that the forward speed of the gusts has a large effect on the lift- and moment-response functions.

Report presenting a study of the use of a magnetic field to control the motion of electrically conducting fluids. Results indicated that the skin friction and heat-transfer rate are reduced when the transverse magnetic field is fixed relative to the plate and increased when fixed relative to the fluid.

Report presenting a single, ordinary, nonlinear differential equation of second order that can be used for determining entry into an exponential planetary atmosphere. The reduced equation includes various terms, some of which represent the gravity force, the centrifugal acceleration, and the lift force. A number of solutions for lifting and nonlifting vehicles entering at various initial angles are obtained from the complete nonlinear equation.

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."

Report presenting heat-transfer measurements made in turbulent flow at a variety of Mach and Reynolds numbers through the use of an axially symmetric annular nozzle consisting of an inner shaped center body and an outer cylindrical sleeve. The results are presented as Stanton number and recovery factor as a function of Reynolds number. Stanton number was found to decrease with an increase in Reynolds number and usually decreases with an increase in Mach number.