Report presenting engine evaluation tests of twelve sets of cermet turbine blades. The first five runs were similar to previous engine tests, but the remaining ones were modified based on information gained during the first runs.

From Summary: "A parameter is introduced which simplifies the accounting for pressure losses in ram-jet combustors. This parameter, called the combustor-force coefficient, relates the jet force and the total pressure at the combustion-chamber entrance. Experimental data for several different combustors are presented for evaluation and comparison."

Memorandum presenting an investigation in which the behavior of parachutes in close proximity to one another was studied by using small parachutes attached to thin wires in the 20-foot free-spinning tunnel. The results indicate that the parachutes, when side by side, generally had little effect on one another and may sometimes have had slight repelling effects.

"Preliminary results of approximately 350 maneuvers of all types performed by a Lockheed F-94B jet interceptor airplane during normal operational training are presented in time-history form and are summarized as maximum load factors, control rates, angular accelerations, and sideslip angles plotted against indicated airspeed. The results were obtained from approximately 350 maneuvers performed by a Lockheed F-94B jet interceptor airplane during squadron operational training" (p. 1).

The results of fuel-air ratio and temperature surveys made in the flame stabilizing zone of a 16-inch ram-jet combustor indicated that the distribution of combustible mixture immediately downstream of a flame holder should be mechanically controlled if a preferred mixture composition is to be maintained in that zone. A sloping-baffle combustor configuration gave combustion efficiencies of 90 percent or greater over a range of fuel-air ratios from 0.010 to 0.045.

Report presenting an investigation of a four-blade single-rotation propeller in combination with an NACA 1-series D-type spinner-cowling combination at Mach numbers up to 0.83. Characteristics of the propeller operating in the presence of the cowling are compared with the characteristics of the propeller with the spinner.

Report presenting an investigation to determine the low-speed large-scale characteristics of an aspect ratio 3 triangular-wing airplane model. The model consisted of the wing in combination with a fuselage of fitness ratio 12.5, a thin, triangular vertical tail with a constant-chord rudder, and a thin, unswept, all-movable tail.

The results of transonic flight measurements of the longitudinal stability characteristics of the Douglas D-558-II research airplane in the original configuration and with outboard fences mounted on the wings are presented. The levels of normal-force coefficient at which the stability decreases and pitch-up starts have been determined for both airplane configurations at Mach numbers up to about 0.94.

Report presenting a theoretical investigation of the lateral stability of a towed high-speed fighter plane using a fighter cruising at supersonic speed at 50,000 feet and a 1000-foot cable. The motion of this configuration was shown to have highly unstable oscillation caused by the towline restraint, but the configuration can be stabilized by choosing the right position for the towline connection and several types of automatic controls.

Report presenting the results of an experimental investigation of several types of aerodynamically balanced trailing-edge flaps on an aspect ratio 2 triangular wing are presented. The balancing devices tested consisted of flap overhang, paddles, rectangular and triangular horns, and trailing-edge tabs. Results regarding the lift, drag, pitching moment, hinge moment, and rolling moment are presented for a range of Mach numbers and a constant Reynolds number.

"The field of a uniformly loaded wing in subsonic flow is discussed in terms of the acceleration potential. It is shown that, for the design of such wings, the slope of the mean camber surface at any point can be determined by a line integration around the wing boundary. By an additional line integration around the wing boundary, this method is extended to include the case where the local section lift coefficient varies with spanwise location (the chordwise loading at every section still remaining uniform)" (p. 471).

Report presenting an investigation to determine the effect of fuel volatility characteristics on the minimum spark energy required to ignite a single tubular turbojet-engine combustor. Results regarding the ignition at sea-level conditions, ignition at altitude conditions, relation between distillation data and minimum ignition-energy requirements, and application of relation to data from a previous investigation are provided.

Report presenting the development of an annular combustor by utilizing the design principles evolved in previous investigations and by making 12 design changes to optimize the altitude performance of the combustor. Three types of fuels were used and the combustion efficiency, pressure losses, and outlet temperature profiles were evaluated.

Investigation of the internal performance characteristics of several jet-exit configurations over a wide range of pressure ratios, which are summarized to provide an overall picture of jet-exit performance. The configurations investigated include a convergent nozzle, fixed convergent-divergent nozzles, an adjustable plug-type convergent-divergent nozzle, and jet ejectors. Results regarding the performance of several jet-exit configurations and matching adjustable jet exits to supersonic aircraft are provided.

Report presenting an investigation of the low-speed stability and control characteristics of a scale model of the proposed MX-1554A design. It employs a triangular wing and triangular stabilizing surfaces. Results regarding the effect of wing incidence, tail position, fences, and chord extensions on the longitudinal characteristics are provided.

Memorandum presenting tensile fatigue tests run on seven turbine-blade alloys at a temperature of 1500 degrees Fahrenheit and a mean stress of 22,000 pounds per square inch with superimposed alternating stresses of 0, 5000, 10,000, and 15,000 pounds per square inch. The same three types of fracture occurring in turbine blades - stress-rupture, stress-rupture followed by fatigue, and fatigue - were obtained in the specimens. Results regarding the effect of alternating stress on mechanism of failure, specimen life, reduction of area of fractured specimens, and effect of specimen shape on life are provided.

Report presenting an investigation of the radiative processes involved in combustion to determine the present role of radiant energy transfer in combustors. The equivalent gray-body emissivity of a hydrocarbon fuel may be increased by use of liquid or solid, soluble or nonsoluble, additives. Results regarding the experimental apparatus and methods, emission characteristics of luminous and nonluminous flames, absorptivity of fuels and of solutions of possible additives, and absorption by slurries are provided.

Report presenting an experimental investigation conducted a Mach number of 3.85 to determine the diffuser characteristics of a series of conventional axially symmetric nose inlets on a ramjet in a supersonic wind tunnel. Performance evaluations of single-cone, double-cone, and isentropic diffusers were made in terms of total pressure recovery and mass flow for a range of angles of attack. Results regarding performance of 1-cone inlets, performance of 2-cone inlets, and performance of isentropic inlets are provided.

Report presenting an experimental investigation at a Mach number of 3.85 in the supersonic wind tunnel to study the flow patterns at the throat of a two-dimensional single-shock diffuser and to evaluate qualitatively several schemes for improving the turning conditions. Schileren observations were made for supercritical inlet operation and conditions of maximum total-pressure recovery.

Report discussing an investigation to determine the cause and provide a fix for the instability in flight of the antisubmarine rocket Mk 1 Mod 0. The Magnus effects and their nonlinear variation with angle of attack were found to affect the stability, so reducing the Magnus effects should reduce instability in the missiles. The greatest reduction of Magnus effects was found through a combination of nose-ring spoiler and the original direction of the propeller rotation, but the nose ring increased the drag.

Memorandum presenting surveys made at the exit of a radial-flow centrifugal impeller to obtain instantaneous values of velocity from blade to blade and at various positions between the front and rear diffuser walls. Surveys were also made at several radial stations midway between the walls of the diffuser to observe the radial change in the flow pattern through the vaneless diffuser. Results regarding typical trace, hub-shroud surveys, and radial surveys are provided.

Report presenting an investigation to determine the importance of molecular-scale processes in the overall turbojet combustion process. The effect of oxygen concentration on the inlet oxygen-nitrogen mixture on the combustion efficiency of a single J33 combustor was determined for a range of combustor-inlet pressures and a range of fuel-flow rates. At a given fuel-flow rate, combustion efficiency decreased at an increasing rate with reduction in oxygen concentration.

Report presenting an investigation of a series of rectangular wing and body combinations at Mach numbers 1.62, 1.93, and 2.41 to determine the effects of aspect ratio, incidence angle, and forebody length on the interference lift, drag, and pitching moment. A limited investigation to determine the effect of Reynolds number on the wings in the presence of the body was also carried out. Information regarding wing lift, basic quantities for interference evaluation, interference qualities, contributions of the various components, and the concept of wing-lift carry-over is provided.

"A preliminary investigation of the flow fluctuations of surge and blade row stall was conducted with three single-stage axial-flow compressors with hub-tip ratios of 0.9,0.8, and 0.5 and with a multistage axial-flow compressor. Flow fluctuations of large amplitude associated with stall were detected in all compressors investigated. The fluctuations were caused by low flow regions affecting 25 to 40 percent of the annulus area and propagating in the direction of compressor rotation, but at a lower speed. Mild audible surge was obtained with the single-stage compressors with hub-tip ratios of 0.9 and 0.8" (p. 1).