From Introduction: "An analysis of an engine having a division of work such that the power of the reciprocating engine is just sufficient to drive the compressor is reported herein. This combination of a reciprocating-type internal-combustion engine that drives its own supercharging compressor and generates gas for further expansion through a turbine will be called a piston-type gas generator in this report."

Memorandum presenting wind-tunnel tests of a semispan model of an unswept wing of aspect ratio 4 and a taper ratio of 0.50, equipped with leading- and trailing-edge flaps. The purpose of the tests was to determine the low-speed aerodynamic characteristics of the wing as affected by the separate or combined deflections of a full-span, constant-chord, leading-edge, plain flap and a partial-plan, constant-chord, trailing-edge flap of either the plain or split type. Results regarding the maximum lift characteristics, pitching-moment characteristics, drag coefficients, lift-drag ratio, and effect of Reynolds number and profile modification are provided.

Report presenting an investigation of a turbojet engine with compressor-inlet total pressure at various values below that of the exhaust pressure to determine engine performance under conditions simulating operation with inlet-duct losses. Results regarding general performance, application to inlet-duct losses, application to airplane boundary-layer control, and application to turbojet-engine thrust control are provided.

Memorandum presenting wind-tunnel tests at high subsonic Mach numbers conducted on a model of a pursuit airplane with a 45 degree sweptback wing. Tests were made to determine the effect of the wing trailing-edge angle, the fuselage contour at the wing-fuselage intersection, and an extension at the leading edge of the wing root.

Report presenting an investigation in the two-dimensional low-turbulence tunnel of a symmetrical airfoil section equipped with a 0.30-airfoil-chord sealed internally balanced flap with a 0.70-flap-chord overhang and a 0.33-flap-chord leading tab. Results regarding airfoil lift, surface pressure, flap hinge-moment, and flap-balance-chamber pressure characteristics at various flap deflections.

Report presenting an investigation of pressure distributions and flow characteristics at low speed through a range of yaw and angle of attack through the stall for three small-scale low-aspect-ratio pointed wings with varying degrees of trailing-edge sweep. An effort was made to correlate pressure distributions with the strong conical vortex flow observed. Results regarding chordwise pressure distributions and flow characteristics, section lift characteristics at zero yaw, spanwise-load distributions, centers of pressure at zero yaw, and wing force and moment characteristics are provided.

Report presenting the effect of flutter characteristics of variation on the aerodynamic shape of concentrated weights rigidly mounted on a simplified wing structure. Two general types of weights with similar mass and moment-of-inertia properties were employed. Results regarding effects of aerodynamic shape of concentrated weights, effects of spanwise variation of light concentrated weights, and effects of moment of inertia of light concentrated weights.

Memorandum presenting a theoretical analysis of the effect of aerodynamic hysteresis on stalling flutter. The results were applied to a given airfoil and correlation of the experimental and theoretical results was found possible by assuming that the angle of aerodynamic lag varies as the slope of the static-lift curve. It was shown that the phenomenon of stalling flutter can at least in some cases be explained on the basis of an aerodynamic lag or hysteresis effect.

Report presenting theoretical calculations made by means of semirigid-flutter theory to determine the effect of centrifugal force on the critical flutter speed of a uniform cantilever beam. Calculations are made on airfoils with fundamental bending frequencies up to 2000 radian per second. Centrifugal force can under certain conditions reduce the critical flutter speed.

Memorandum discussing four related methods for the study of compressible flow by means of the linear perturbation theory for the case of three-dimensional flow with axial symmetry. A general method which includes the other is also discussed briefly. In each case, the properties of the compressible flow are obtained from those of a corresponding incompressible flow.

Contains results of calculations made to determine the neutral oscillatory stability boundaries, period and time to damp of the oscillatory mode, and motions following disturbances. The calculations were made for Mach numbers of 0.75 and 2.3 at an attitude of 35,000 feet and for the landing condition at sea level.

Report presenting numerical results of flutter calculations for a two-blade helicopter using a see-saw-type rotor. The stability condition for oscillatory motion is expressed in terms of a small number of composite parameters that are evaluated from moments of inertia, angle settings, and aerodynamic parameters of a blade. The analysis indicated that a see-saw rotor with a coning angle is more unstable than an airplane wing with the same parameters.

Report presenting testing in the X-4 airplane to obtain stability and control data. The flight was made with the center of gravity at 19.7 percent of the mean aerodynamic chord and with the rudder-boost system removed. The results showed that the longitudinal stability was positive in the clean condition and in the gear-down flaps-up condition.

"This paper presents some data on the dynamic lateral stability characteristics of the Douglas D-558-II (BuAero No. 37974) airplane. For the airplane in the clean condition, the lateral oscillations are lightly damped. In the landing condition, the airplane performs a constant-amplitude lateral oscillation" (p. 1).

Memorandum presenting an investigation of a typical inlet stage of a multistage axial-flow compressor that was designed on the basis of an analysis of basic design variables. The stage, consisting of 19 rotor blades and 20 stator blades with 40 inlet guide vanes, had a hub-to-tip-radius ratio at the rotor inlet of 0.50 and a rotor-blade outside diameter of 14 inches. Results regarding the overall compressor performance, comparison of compressor performance with design, and rotor-row performance are provided.

Report presenting an investigation to determine the performance of a Bumblebee 18-inch ram jet with a rake-type flame holder was conducted using kerosene and propylene oxide as fuels. Experiments occurred at a range of pressure altitudes and ram-pressure ratios over the operable range of fuel-air ratios. Use of propylene oxide was found to improve the stability of combustion, increased the operable range of fuel-air ratios, and allowed ignition at high values of combustion-chamber-inlet velocities.

"Tests were made with a C-54 airplane in which airline pilots made several blind approaches to determine whether any special flying techniques were used in blind landings and whether any special handling-qualities requirements would have to be formulated because of such special techniques. It was found that the airplane was flown at all times in the normal manner; that is, all turns were banked turns that were nearly coordinated by use of the rudder so that the sideslip was held close to zero. The pilot expended considerable physical work in continually moving the controls but this wake was due in part to the large friction in the three control systems" (p. 1).

An analysis is presented of rim cooling of gas-turbine blades; that is, reducing the temperature at the base of the blade (wheel rim), which cools the blade by conduction alone. Formulas for temperature and stress distributions along the blade are derived and, by the use of experimental stress-rupture data for a typical blade alloy, a relation is established between blade life (time for rupture), operating speed, and amount of rim cooling for several gas temperatures. The effect of blade parameter combining the effects of blade dimensions, blade thermal conductivity, and heat-transfer coefficient is determined. The effect of radiation on the results is approximated. The gas temperatures ranged from 1300F to 1900F and the rim temperature, from 0F to 1000F below the gas temperature. This report is concerned only with blades of uniform cross section, but the conclusions drawn are generally applicable to most modern turbine blades. For a typical rim-cooled blade, gas temperature increases are limited to about 200F for 500F of cooling of the blade base below gas temperature, and additional cooling brings progressively smaller increases. In order to obtain large increases in thermal conductivity or very large decreases in heat-transfer coefficient or blade length or necessary. The increases …

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The basic lateral stability characteristics of the complete model with undeflected control surfaces are presented in the present report with a very limited analysis of the results.

From Summary: "An investigation was conducted on a large centrifugal compressor from an experimental turbojet engine to determine the performance of the compressor and to obtain fundamental information on the aerodynamic problems associated with large centrifugal-type compressors. The results of the research conducted on the compressor indicated that the compressor would not meet the desired engine-design air-flow requirements (78 lb/sec) because of an air-flow restriction in the vaned collector (diffuser). Revision of the vaned collector resulted in an increased air-flow capacity over the speed range and showed improved matching of the impeller and diffuser components."

A theoretical analysis of the temperature distribution through the trailing portion of a blade near the coolant passages of liquid cooled gas turbines was made. The analysis was applied to obtain the hot spot temperatures at the trailing edge and influence of design variables. The effective gas temperature was varied from 2000 degrees to 5000 degrees F in each investigation.

Spin tests have been performed in the Langley 20-foot free-spinning tunnel on a 1/35-scale model of the Douglas XB-43 airplane. The spin and recovery characteristics were determined for several loading conditions of the airplane. The effects of installing a dorsal fin and of installing a ventral fin were investigated. Emergency escape of the crew was simulated and the stick and rudder pedal forces necessary to effect recoveries on the airplane were determined.

An investigation was conducted on an 0.08-scale semispan model of the Chance Vought XF7U-1 airplane in the Langley high-speed 7- by 10-foot tunnel in the Mach number range from 0.40 to 0.97. The results are compared with those obtained with an 0.08-scale sting-mounted complete model tested in the same tunnel and with an 0.026-scale semispan model tested by the wing-flow method. The lift-curve slopes obtained for the 0.08-scale semispan model and the 0.026-scale wing-flow model were in good agreement but both were generally lower than the values obtained for the sting model.

"An investigation was conducted to determine the performance characteristics of the axial-flow supersonic compressor of the XJ55-FF-1 turbojet engine. An analysis of the performance of the rotor was made based on detailed flow measurements behind the rotor. The compressor apparently did not obtain the design normal-shock configuration in this investigation. A large redistribution of mass occurred toward the root of the rotor over the entire speed range; this condition was so acute at design speed that the tip sections were completely inoperative" (p. 1).