Memorandum presenting a preliminary investigation made in the two-dimensional low-turbulence tunnel on an NACA 64A010 airfoil with permeable surfaces to obtain an indication of the stabilizing effect of area suction on the laminar boundary layer. Although the airfoil surface had many waves and irregularities of contour, the data corroborated qualitatively the theoretically predicted stabilizing effect of area suction on a smooth flat plate.

Combustion chamber liners for gas turbines and experimental set-ups were tested for failure. A ceramic-lined test chamber was operated at fuel/air ratios up to 0.050. Thermal-shock evaluation indicated that a ceramic lining, which expands after firing, would crack but would not fall apart during operation. Refractoriness of the lining and the resistance to mechanical shock were adequate. In general, shell temperature reductions of approximately 400 deg F were effected by the use of this lining at fuel/air ratios of 0.016 and 0.050. The mechanism of failure of the ceramic lining was induced by sudden heating and cooling during operation.

Report presenting information about some of the fundamental concepts and lines of development that may be undertaken regarding helicopter stability. Some of the principles discussed include method of control, control lag, stability characteristics, control forces, and center of gravity. Some of the means for improvement discussed include use of a horizontal stabilizer, use of trim devices, use of power-operated controls, automatic controls, and choice and grouping of indicating instruments.

Report presenting an investigation of a one-eighth segment of an annular combustor suitable for use as a component of an experimental turbojet engine. Due to the small space available for the combustor, a special design involving a minimum of obstructions in the combustion chamber was created. Results regarding the temperature-rise efficiency, total-pressure loss, and exhaust-gas temperature variation for several simulated engine operating conditions are provided.

An investigation conducted in the icing research tunnel to determine aerodynamic and icing characteristics of two flush-inlet-type fuel cell vent installations. The vent tubes were mounted in two different locations in the two installations. The vents were aerodynamically investigated to obtain vent-tube static-pressure differentials and pressure surveys as a function of tunnel-air velocity and angle of attack.

Report discussing an aerodynamic control effectiveness study using free-flight, rocket-propelled test vehicles. Information about the effects of wing sweepback, aspect ratio, taper ratio, and section thickness ratio on the rolling effectiveness of full-span, sealed ailerons is provided.

Report presenting an extensive collection of lift and hinge-moment characteristics of control surfaces up to a Mach number of 0.90 in a high-speed wind tunnel. A wide variety of control-surface profiles, plan forms, and aerodynamic balances are included. Results regarding elevator hinge moments and longitudinal control, aileron hinge moments and lateral control, control-surface characteristics, and transonic flutter are highlighted.

Memorandum presenting the results of a wind-tunnel investigation of the low-speed characteristics of horizontal tails of aspect ratio 3 with unswept and swept-back plan forms. Two models were tested which had identical areas, aspect ratio, taper ratio, and airfoil section, differing only in the angle of sweepback and elevator area ratios. The major effect of sweepback was to increase the rate of change of hinge-moment coefficient with angle of attack, to reduce the rate of change with elevator deflection, and to reduce the elevator effectiveness.

From Summary: "The effects of externally mounted rockets and fuel tanks on the aerodynamic characteristics of an airplane model with a swept-back wing are presented in this report."

Memorandum presenting an investigation conducted to determine experimentally turbine-nozzle-blade and turbine-bucket temperatures in a turbojet engine and to correlate these temperatures with the gas temperatures. Data were obtained over the normal range of engine speeds and with two tail-pipe-nozzle areas. Results regarding basic data, turbine-nozzle-blade temperature distribution, turbine-bucket-temperature distribution, temperature distribution of gas at burner-outlet, turbine-bucket temperatures during starting, and relation of material and gas temperatures are provided.

Report presenting flight measurements obtained during acceptance tests conducted by the Bell Aircraft Corporation on the XS-1 research airplane. The primary focus was on the aerodynamic loads, handling qualities, maximum lift, and buffet boundaries of the airplane.

From Introduction: "Analyses that provide a basis for comparing the centrifugal-stress distributions inherent in jet-engine turbine blades of several designs currently in use were therefore made and are presented."

Memorandum presenting wind-tunnel tests conducted to determine the high-speed stability and control characteristics of an airplane model with a sweptback wing and tail. The aerodynamic coefficients and the longitudinal- and lateral-control characteristics of the plain wing-fuselage-tail combination are included. Results regarding lift, drag, and pitching moment, longitudinal characteristics, lateral characteristics, wing leading-edge slate, and fuselage-side dive brakes are provided.

Report presenting a model with a nozzle upstream of an annular duct inlet for the purpose of ejecting high-velocity air into the boundary layer of the flow along the forebody tested between Mach numbers of 1.36 and 2.01. Results wind-tunnel data, equivalent pressure recovery, and scale effects are provided.

The vibration characteristics of a group of axial-flow compressor blades of similar geometry were investigated. Empirical-mode constants were determined for the first three bending and torsional modes. A comparison of experimentally determined frequencies of a second group of blades with frequencies computed using these mode constants showed that the computed values were correct within 10 percent. The approximate limiting ratios of depth to chord and length to chord below which these constants could not be used to compute the natural frequencies were also found experimentally.

Report presenting a method for applying the limited contraction ratio to obtain the maximum allowable blade thickness of a two-dimensional model of a supersonic-compressor rotor.

Report presenting testing on parabolic bodies of revolution of two fineness ratios in the transonic and supersonic range. One had a body fineness ratio of 7.87 and one had a ratio of 12 and were tested under different Mach number ranges. Experimental results and drag estimates of various portions of the body are provided.

Results are presented of tests up to a Mach number of 0.92 at altitudes around 30,000 feet. The data obtained show that the airplane can be flown to this Mach number above 30,000 feet. Longitudinal trim changes have been experienced but the forces involved have been small. The elevator effectiveness decreased about one-half with increase of Mach number from 0.70 to 0.87.

Report presenting an experimental investigation to determine the vibration phenomena that occur in turbine blades of a typical jet-propulsion engine during service operation; high-temperature strain gages were used to measure the turbine-blade vibrations. Results regarding modes of vibration, centrifugal stresses, and vibration of turbine blades during operation are provided.

Report presenting data from two experiments. One used the NACA RM-2 drag research model equipped with a pilot's canopy to determine the effect on aerodynamics. The other was conducted with the same configuration and returned similar results.

Report presenting an investigation in the two-dimensional low-turbulence tunnel on an NACA 64A010 airfoil with permeable surfaces to obtain an indication of the stabilizing effect of area suction on the laminar boundary layer. The surface of the airfoil that was tested had a lot of waves and irregularities, but the theoretically predicted stabilizing effect of area suction on a smooth flat plate was still observed.

Report discussing an investigation into chord-extension controls, conventional ailerons, and spoilers on a 45 degree swept-back wing of aspect ratio 4.5 and taper ratio 0.5. Measurements of the lift, drag, pitching moments, rolling moments, and rates of roll produced by the various controls are described. The results on a semispan model and a full-span model are described.

Memorandum presenting the results of measurements of gust and draft velocities within thunderstorms at a selected air field over a 5-day period. They are also compared to previous flights.

Report presenting measurements of the handling qualities of the Bell XS-1 transonic airplane using NACA instruments. Information regarding the stability and control characteristics and aerodynamic loads was obtained using two different airplanes in gliding and powered flight. Results regarding the longitudinal and lateral stability and control and stalling characteristics are provided.