Memorandum presenting measurements of some of the high-speed characteristics of the D-558-1 airplane up to Mach number 0.89. The results of the tests showed that the stabilizer incidence drastically affected the longitudinal trim characteristics above a Mach number of 0.80.

Memorandum describing a way in which the data of three previous reports can be used to compute the incompressible flow fields for cowling-spinner combinations and open-nose inlets for use in the design of propeller shanks and cuffs. The method consists of regarding the cowling surface as replaced by a ring vortex sheet whose strength at any point is equal to the local tangential velocity.

Report presenting free-flight investigations conducted on four 16-inch-diameter ramjet units to determine the performance at high subsonic and supersonic velocities. Data for evaluating the performance were obtained from radio-telemetering and radar-tracking equipment. Results regarding combustion performance, diffuser total-pressure recovery, thrust coefficient, and external drag coefficient are provided.

Report presenting an investigation with a ram-jet combustion chamber to determine the effect of fuel-air ratio and the inlet-air parameters of pressure, temperature, and velocity on combustion limit, combustion efficiency, and flame length.

From Summary: "Measurements of wing and fuselage pressure distributions were made at low and high subsonic Much numbers on a 0.16-scale model of the projected MX-656 research airplane. The MX-656 is a supersonic design utilizing a low-aspect-ratio wing and tail. Pressure-distribution measurements indicated that, although the critical Mach number of the wing was approximately 0.81 at 0 degree angle of attack, compressibility effects were of little significance below a Mach number of at least 0.90. The principal effect of compressibility was an increase in the pressure gradient over the after 30 percent of the wing chord, causing a tendency for the flow to separate."

"An investigation of the XJ-41-V turbojet-engine compressor was conducted 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 original compressor indicated the compressor would not meet the desired engine-design air-flow requirements because of an air-flow restriction in the vaned collector. The compressor air-flow choking point occurred near the entrance to the vaned-collector passage and was instigated by a poor mass-flow distribution at the vane entrance and from relatively large negative angles of attack of the air stream along the entrance edges of the vanes at the outer passage wall and large positive angles of attack at the inner passage wall" (p. 1).

Report presenting testing of a twin-scoop duct inlet that enclosed 37.2 percent of the forebody circumference at Mach numbers between 1.36 and 2.01. The approach to each scoop consisted of a ramp that deflected the flow to create an oblique shock wave in front of the duct entrance. Results regarding the inlet proportions, ramp angle, slots, and angle of incidence are provided.

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.

"Previous performance data of the 19XB axial-flow compressor indicated that the outlet guide vanes and possibly the inlet guide vanes were stalling. Calculations were made to determine if these adverse conditions could be eliminated and if the manufacturer's design specifications could be more nearly approached by altering the blade angles of the first few compression stages as well as the outlet guide vanes. With the blade angles altered, experimental data were taken at compressor speeds of 8500 to 17,000 rpm with inlet-air conditions of 7.4 inches of mercury absolute and 59 degrees Fahrenheit" (p. 1).

"Data for a liquid-cooled engine with a displacement volume of 1710 cubic inches were analyzed to determine the effect of exhaust pressure on the engine cooling characteristics. The data covered a range of exhaust pressures from 7 to 62 inches of mercury absolute, inlet-manifold pressures from 30 to 50 inches of mercury absolute, engine speeds from 1600 to 3000 rpm, and fuel-air ratios from 0.063 to 0.100. The effect of exhaust pressure on engine cooling was satisfactorily incorporated in the NACA cooling-correlation method as a variation in effective gas temperature with exhaust pressure. Large variations of cylinder-head temperature with exhaust pressure were obtained for operation at constant charge flow" (p. 1).

Report presenting testing of a semispan model of a wing of triangular plan form and aspect ratio 2 in the 12-foot pressure tunnel to determine the aerodynamic characteristics of the wing as influenced by the independent effects of Reynolds number and Mach number up to Mach numbers approaching unity. Results regarding the effect of body and effect of wing-profile modification are also provided.

An investigation of a 1/18-scale dynamically similar model of the North American B-45 airplane was made to observe the ditching behavior and determine the proper landing technique to be used in an emergency water landing. Various conditions of damage were simulated to determine the behavior which probably would occur in a full-scale ditching. The behavior of the model was determined from high-speed motion-picture records, time-history acceleration records, and visual observations. It was concluded that the airplane should be ditched at the maximum nose-high attitude with the landing flaps full down for minimum landing speed. During the ditching, the nose-wheel and bomb-bay doors probably will be torn away and the rear of the fuselage flooded. A violent dive will very likely occur. Longitudinal decelerations of approximately 5g and vertical accelerations of approximately -6g (including gravity) will be experienced near the pilots' compartment. Ditching braces installed in the bomb bay will tend to improve the behavior slightly but will be torn away along with the bomb-bay doors. A hydroflap installed ahead of the nose-wheel doors will eliminate the dive and failure of the nose-wheel doors, and substantially reduce the motions and accelerations.

From Summary: "An investigation was conducted in the NACA Cleveland altitude wind tunnel to determine the operational characteristics of the Westinghouse 19B-2, 19B-8, and 19XB-l jet-propulsion engines. The 19B engine is one of the earliest experimental Westinghouse axial flow engines. The 19XB-1 engine is an experimental prototype of the Westinghouse 15 series, having a rated thrust of 1400 pounds. Improvements in performance and operational characteristics have resulted in the 19XB-2B engine with a rated thrust of 1600 pounds. The operational characteristics were determined over a range of simulated altitudes from 5000 to 30,000 feet for the 19B engines and from 5000 to 35000 feet for the 19XB-l engine at airspeed from 20 to 380 miles per hour."

Memorandum presenting measurements of gust and draft velocities within cumulus clouds at a certain army air field using an AT-6 airplane. The measurements were made to supplement the at a obtained with P-61C airplanes. The data are summarized in tables.

Tests of a PB2Y-3 flying boat were made at the U.S. Naval Air Station, Patuxent River, Md., to determine its hydrodynamic trim limits of stability. Corresponding tests were also made of a 1/8-size powered dynamic model of the same flying boat in Langley tank no. 1. During the tank tests, the full-size testing procedure was reproduced as closely as possible in order to obtain data for a direct correlation of the results. As a nominal gross load of 66,000 pounds, the lower trim limits of the full-size and model were in good agreement above a speed of 80 feet per second. As the speed decreased below 80 feet per second, the difference between the model trim limits and full-scale trim limits gradually became larger. The upper trim limit of the model with flaps deflected 0 deg was higher than that of the full-size, but the difference was small over the speed range compared. At flap deflections greater than 0 deg, it was not possible to trim either the model of the airplane to the upper limit with the center of gravity at 28 percent of the mean aerodynamic chord. The decrease in the lower trim limits with increase in flap …

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 aileron characteristics of the complete model are presented in the present report with a very limited analysis of the results.

Report presenting a discussion of a number of the problems that most frequently arise with airfoils on helicopters. A reference list of published reports on airfoil section characteristics which are useful in regards to these helicopter problems is also included.

From Summary: "The pressure drops through electrically heated Inconel tubes with length-diameter ratios of 29.25, 58.50, 87.75, and 117.00 have been measured at entrance Mach numbers from approximately 0.12 to the value at which choking occurred. The heat-input rate was varied from zero to the highest values allowable without damaging the tubes. Experimental data and a number of computed variables are presented in tabular form."

Pressure measurements were made during wind-tunnel tests of the McDonnell XP-85 parasite fighter. Static-pressure orifices were located over the fuselage nose, over the canopy, along the wing root, and along the upper and lower stabilizer roots. A total-pressure and static-pressure rake was located in the turbojet engine air-intake duct. It was installed at the station where the compressor face would be located. Pressure data were obtained for two airplane conditions, clean and with skyhook extended, through a range of angle of attack and a range of yaw.

Report presenting an investigation of the hydrodynamic take-off and landing characteristics of a model of a hypothetical jet- and rocket-propelled high-speed airplane fitted with various designs of a single monoplane hydrofoil mounted near the center of gravity. This testing is performed to determine the feasibility of the water-based operation of high-speed airplanes. Results regarding the general hydrodynamic characteristics, development of hydrofoils, and effects of some hydrofoil parameters are provided.

Report presenting an investigation of turbine operating temperatures as affected by liquid cooling, especially if materials of high conductivity are used, at gas temperatures up to 1925 degrees Fahrenheit. Results regarding the statio heat-transfer rig and turbine rig are provided. The investigation showed that nonstrategic material such as aluminum alloy can be used in liquid-cooled turbine wheels at high gas temperatures.

From Summary: "Drag measurements at transonic speeds on rectangular airfoils and on airfoils swept back 450 are reported. These airfoils, which were mounted on cylindrical test bodies, are part of a series being tested in free drops from high altitude to determine the effect of variation of basic airfoil parameters on airfoil drag characteristics at transonic speeds. These rectangular and swept-back airfoils had the same span, airfoil section (NACA 65-009), and chord perpendicular to the leading edge. The tests were made to compare the drag of rectangular and sweptback airfoils at a higher aspect ratio than had been used in a similar comparison reported previously."

Tests have been conducted to determine the drive-motor torque and the static force and moment characteristics of the AN/SPS-1 radar antenna. Shifting the longitudinal position of the antenna had very little effect on the drive-motor torque, which reached a maximum value expressed in terms of dynamic pressure (T/q)(sub max) of 1.15 at an azimuth angle of 245. The maximum observed values of rolling, pitching, and yawing moments in terms of dynamic pressure are -29.0, 66.6, and 13.4, respectively.

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.