Report presenting an investigation of the lateral stability and control effectiveness of a model of a fighter-type airplane model with a low-aspect-ratio and 3.4-percent-thick wing with negative dihedral at a range of Mach numbers, sideslip angles, and angles of attack. Results regarding the lateral characteristics at zero angle of attack, lifting conditions, and lateral and directional controls are provided.

Memorandum presenting an annotated bibliography of NACA reports containing information of interest to designers and manufacturers of controls for turbojet engines. The eleven major topics include starting, acceleration, flame-out, temperature control, stability and dynamics of small disturbances, combustion dynamics, engine inlet diffuser control, steady-state engine performance, fuel systems, sensors, and general control system theory.

Research conducted at the NACA Lewis Laboratory on ignition of flowing gases by means of long-duration discharges is summarized and analyzed. Data showing the effect of a flowing combustible mixture on the physical and electrical characteristics of spark discharges and data showing the effects of variables on the spark energy required for ignition that has been developed to predict the effect of many of the gas-stream and spark variables is described and applied to a limited amount of experimental data.

Memorandum presenting an investigation of a full-scale afterburner with high burner-inlet velocity conducted to determine burner performance with several variations in burner design. Variables receiving particular attention were flameholder design and burner length. Results regarding diffuser performance, performance of the reference two-V-gutter flameholder, designs to improve combustion for high-velocity conditions, and operational characteristics are provided.

Memorandum presenting an investigation to determine the roll effectiveness of a differentially deflected horizontal tail of a 42 degree swept-wing model. The model was tested through an angle-of-attack range of 0 degrees through the stall in the clean and landing configurations with the horizontal tail in a low position. Results regarding the longitudinal characteristics and lateral characteristics are provided.

Report presenting an investigation on a transonic bump to determine the aerodynamic characteristics of a series of triangular wings. Four basic triangular-wing plan forms with different aspect ratios, taper ratios, and combinations of tip clipping were tested over a range of Mach and Reynolds numbers. Results regarding angle of attack, drag coefficient, pitching-moment coefficient with lift coefficient, and various curves are provided.

Note presenting general equations for the linear responses of inner- and outer-spool speed to change in turbine-inlet temperature and exhaust-nozzle area are derived and evaluated from hypothetical two-spool-engine characteristics at design speed. Experimental corroboration of analysis is also provided in the form of response to fuel flow, response to exhaust-nozzle area, and response to turbine-inlet temperature are provided.

Report presenting the results of flight tests with several typical light aircraft. Flight tests were made with one airplane with two different horizontal tail configurations in an attempt to provide an arrangement that would give optimum conditions with regard to the effect of power change on longitudinal trim near the stall. The results are intended to provide quantitative flight-test information which may be useful to designers in attempting to provide for adequate low-speed control and which may be correlated with analytical analyses.

Note presenting some analytical means by which designers may estimate the elevator deflection required to trim in steady longitudinal flight and to demonstrate in a quantitative manner the effects on longitudinal trim of changes in some of the more important design parameters. The procedures can result in a design in which the maximum up-elevator deflection can be maintained within the highest value that will result in satisfactory damping in roll and reliable lateral control under all flight conditions, while, at the same time, adequate longitudinal control is available.

Note presenting measurements of space heating rate, which can yield information that is useful in characterizing turbulent combustion. For Bunsen burner flames stabilized over a field of pipe-induced turbulence, the space heating rate decreased with increasing linear flow and burner diameter and was independent of pilot conditions. Results regarding residual heat values, space conversion rate, turbulent burning velocities, and a comparison of concepts are provided.

Report presenting an investigation to determine the effect of type and location of impact damage on the fatigue strength of jet-engine compressor blades. The most serious damage was found in the nicks at the leading and trailing edges in the vicinity of the maximum-vibratory-stress section of the airfoil. Results regarding stress distribution in the blades, fatigue of the damaged blades, the fatigue test results, the correlation of reduction in strength, an analysis of the results, and testing using reworked blades are provided.

Report presenting an analysis of temperatures and thermal stresses in typical skin-stiffener combinations of winglike structures subjected to aerodynamic heating using an electronic differential analyzer. Variations were made in aerodynamic heat-transfer parameter, in a joint conductivity parameter, and in the ratio of skin width to skin thickness. Results regarding data obtained,an illustrative example, temperature and stress ratios, and peak stress ratios and temperature-ratio drop across joint are provided.

Report presenting a method for obtaining a power spectrum of gust vertical velocity over a wide range of wavelengths from simultaneous measurements in flight. It has the advantage of not involving the use of airplane transfer functions. Results regarding the measurements of velocity, including long-period and short-period measurements, and a composite spectrum over the range of frequencies are provided.

"Tests utilizing the schileren method of flow photography have been conducted to provide a comparison of the complete flow fields past an unswept- and a swept-wing-body combination and the flow fields past their equivalent bodies of revolution at Mach numbers around 1.0. The results indicated that the shock growth and positions on the wing-body combinations were closely reproduced in the flow past the equivalent body" (p. 1).

Report presenting an investigation in the 300 mph 7- by 10-foot tunnel and gust tunnel to determine the static longitudinal aerodynamic characteristics an the gust-alleviation capabilities of forward-located fixed spoilers, deflectors, or a spoiler-deflector combination on a simulated transport airplane model with an unswept wing. Results regarding the static/force test, dynamic/gust-tunnel test, and short-period frequency and damping are provided.

Formulas for the wave drag of shrouded symmetrical airfoils and shrouded bodies of revolution of arbitrary shape are derived by means of linearized theory. In the case of the airfoils, the shroud consists of flat plates and for the bodies of revolution the shroud is a cylindrical shell. The results obtained hold for a Mach number range dependent on the geometry of the configuration. Expressions are also given for determining a class of body shapes for which the wave drag is theoretically zero.

Report presenting fatigue testing in rotating bending on severely notched bars machined from 2024-T4 aluminum-alloy extruded round rods. Two sizes of specimens were studied.

"Experimental results of lifts and moments about the quarter chord of a two-dimensional wing at subsonic Mach numbers are presented. A comparison of the experimental magnitude of the lift vector with the theory as given by Dietze showed good agreement. Comparisons of the moments and the quadrature component of lift with theory indicated that some refinements in the testing technique are necessary for the experimental determination of these quantities in the transonic range" (p. 1).

Report presenting the results of an investigation on the flutter of propeller blades with three different plan forms. The propellers tested included one with highly twisted 2-percent-thick blades, 6-percent-thick blades, and two sets of 3-percent-thick blades with different internal damping. Results regarding the effect of various parameters on the stall flutter boundaries and blade stresses near the flutter boundary are provided.

Results are presented from an investigation of the variation with Reynolds number and Mach number of the total, base, and skin-friction drag of seven boattail bodies of revolution designed for minimum wave drag according to the theory of NACA-TN-2550. The tests covered a Reynolds number range from approximately 1.0 x 10(6) to 10.0 x 10(6) at Mach numbers of 1.62, 1.93, and 2.41 respectively.

Note presenting an investigation of the problem of selecting heat-exchanger configurations for optimum performance. The method of optimization is illustrated for several compact heat-exchanger configurations where a prescribed amount of heat is transferred. The results for heat-exchanger configurations for which data is reported in the literature are presented in the form of charts illustrating the method of analysis and results that can be drawn.

Note presenting an analysis of fixed- and free-turbine engines applicable to helicopter propulsion. Generalized performance charts are presented for the engines and comparisons are made of off-design specific fuel consumption, altitude performance, power-speed characteristics, and response times. At design shaft speeds and turbine-inlet temperature ratios, the equivalent power developed by both the fixed- and free-turbine engines was about 91.4 horsepower per pound of air per second.

Report presenting surveys made through a turbulent boundary layer on a flat plate by means of a pitot probe, an X-ray densitometer, and hot-wire and cold-wire probes. Results were analyzed to determine the reliability of basic data and how well the distributions of properties in the boundary layer compare with those assumed in theoretical analyses.

Report presenting the performance of four 90 degree bends in ducts of constant diameter with differing ratios of radius of curvature to diameter over a range of inlet Mach numbers extending up to the choking condition for a thin and thick inlet boundary layer. An increase in the inlet boundary-layer thickness decreased the choking Mach number for each of the elbows, and had little other effect on performance parameters.