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 presenting an investigation of the pressure distributions over the drooped-nose flap of a 42 degree sweptback wing with circular-arc airfoil sections and half-span trailing-edge split flaps in the 19-foot pressure tunnel. The effects of the deflection and span of the drooped-nose flap and effects of split trailing-edge flaps on the pressures over the drooped-nose flap were determined.

Report discusses the results of an investigation into the aerodynamic characteristics of models of a tailless, pursuit-type, supersonic airplane employing a wing of triangular plan form. Measurements of lift, drag, and pitching moment, side force, drag, and yawing moment are described for several angles of attack and angles of yaw. Information about elevator and rudder behavior is also described.

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.

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."

Report presenting an investigation using the NACA wing-flow method to determine the longitudinal stability and control characteristics at transonic speeds of a semispan airplane with a 45 degree sweptback wing and tail. Measurements of the lift and angle of attack for trim were made for several stabilizer and elevator settings. Testing was also performed to investigate the effects of transition wires mounted on the wing and tail, the effect of increasing the boundary-layer thickness on the test surface, and the effectiveness of a wing flap with a sweepback of 45 degrees.

Memorandum presenting some pressure-distribution and boundary-layer measurements made in flight in the presence of shock on two modifications of the local contour of the wings of a high-speed airplane. Results regarding the pressure distribution, boundary-layer surveys, and effects on test airplane 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 the results of an estimation of the limit forces on airfoils at supersonic speeds. The limit pressure coefficient attainable on an airfoil is shown to be about 70 percent of the pressure coefficient for a vacuum over a wide range of Mach numbers.

Two low-acceleration transonic-flutter vehicles were launched and flown. The first carried two test wings, one of which fluttered at M = 0.92 at a frequency of 61.4 cycles per second. The reference flutter speed determined from two-dimensional theory for an unswept wing in incompressible flow is conservative when compared to the experimental flutter speed. The second vehicle carried two test wings, one of which failed at M = 0.71 because of low-frequency divergent oscillation. Since this failure was not caused by conventional flexure-torsion flutter, no comparison with a reference flutter speed can be made.

Report presenting an investigation of burner liners in a turbojet engine to determine the principal factors limiting the burner-liner service life. The investigation covered a range of engine speeds and testing was conducted to determine whether bare, ceramic-coated, or shielded thermocouples would give the most correct temperature readings.

Report presenting several rectangular and tapered wing configurations with leading-edge and trailing-edge ailerons tested as part of a general investigation of an aerodynamic control at supersonic speeds. Results indicated that the use of the leading-edge aileron alone was ineffective or caused negative control until a high Mach number was attained. Results for the untapered configurations, tapered configurations, and drag measurements are provided.

An X-ray - diffraction analysis of residual surface stresses after plastic strain was introduced in a parallel-sided 3S-O aluminum disk with a central hole by two types of centrifugal overspeed is reported. Both tangential and radial stresses were generally tensile with large local variations near the hole where surface stresses may have been partly superficial. These stresses were both tensile and compressive dependent on the distance from the disk center when mass compression was effected near the hole.

Report presenting results obtained to determine the effects of compressibility at high Mach numbers on a scale model of the Bell XS-1 transonic research airplane. The results are presented for several model configurations through a range of Mach numbers. Results regarding aerodynamic characteristics and static longitudinal stability characteristics are provided.

"An investigation has been conducted in the NACA Cleveland altitude wind tunnel to evaluate the performance and windmilling drag characteristics of an original and a modified turbojet engine of the same type. Data have been obtained at simulated altitudes from 5000 to 45,000 feet, simulated flight Mach numbers from 0.09 to 1.08, and engine speeds from 4000 to 12,500 rpm. Engine performance data are presented for both engines to show the effects of altitude at a flight Mach number of 0.25 and of flight Mach number at an altitude of 25,000 feet" (p. 1).

Combustion chamber performance properties of a 3000-pound-thrust axial-flow turbojet engine were determined. Data are presented for a range of simulated altitudes from 15,000 to 45,0000 feet and a range of Mach numbers from 0.23 to 1.05 for various modifications of the engine.

An investigation was conducted to evaluate the operational characteristics of a 3000 pound thrust axial flow turbojet engine over a range of simulated altitudes from 2000 to 50,000 feet and simulated flight Mach numbers from 0 to 1.04 throughout the operable range of engine speeds. Engine operating range, acceleration, deceleration, starting, altitude, and flight Mach number compensation of the fuel control system, and operation of the lubrication system at high and low ambient air temperatures were evaluated.

A wind tunnel investigation was conducted to determine the performance of a turbine operating as an integral part of a turbojet engine. Data was obtained while the engine was running over full operable range of speeds at various altitudes and flight mach numbers, and with four nozzles of different outlet areas.A maximum turbine efficiency of 0.875 was obtained at altitude of 15 thousand feet, Mach number 0.53, and corrected turbine speed of 5900 rpm.

Compressor performance properties for two 11-stage compressors of 3000-pound-thrust axial-flow turbojet engines were determined. Data are presented for a range of simulated altitudes and a range of Mach numbers for various modifications of the engine.

"An investigation of the XJ-41-V turbojet-engine compressor with a revised vaned collector was conducted to determine the performance of the compressor and to obtain fundamental information on the aerodynamic problems associated with large centrifugal compressors of this type. The original vaned collector was revised by increasing the flow area at the vaned collector entrance. A maximum adiabatic efficiency of 0.81 was obtained at a corrected weight flow of 36.5 pounds per second and a pressure ratio of 1.90" (p. 1).

"An extended analysis was made of the previously reported performance investigation of the original compressor from the XJ-41-V turbojet engine and a similar compressor revised a to obtain a 33-percent increase in the geometric passage area at the vaned-collector entrance. This analysis was based on the concept of the vaned-collector entrance as the throat section of a nozzle. Because of nonuniform air distribution at the vaned-collector entrance, approximately 90 percent of the available flow area was utilized in the original compressor and 94 percent in the revised compressor" (p. 1).

From Summary: "Flight tests have been made to determine the longitudinal stability and control and stalling characteristics of a North American P-51H airplane. The results indicate that the airplane has satisfactory longitudinal stability in all the flight conditions tested at normal loadings up to 25,000 feet altitude. At Mach numbers above 0.7, the elevator push force required for longitudinal trim decreased somewhat because of compressibility effects."

"Tests were made of a 1/18-scale dynamically similar model of the Lockheed Constellation airplane to investigate its ditching characteristics and proper ditching technique. Scale-strength bottoms were used to reproduce probable damage to the fuselage. The model was landed in calm water at the Langley tank no. 2 monorail. Various landing attitudes, speeds, and fuselage configuration were simulated" (p. 1).

From Summary: "An investigation has been conducted in the NACA Cleveland altitude wind tunnel to evaluate the operational characteristics of a 3000-pound-thrust axial-flow turbojet engine over a range of simulated altitudes from 2000 to 50,000 feet and simulated flight Mach numbers from 0 to 1.04 throughout the operable range of engine speeds. Operational characteristics investigated include engine operating range, acceleration, deceleration, starting, altitude and flight-Mach-number compensation of the fuel-control system, and operation of the lubrication system at high and low ambient-air temperatures."