Report presenting a survey of various types of catapults in connection with the problem of accelerating a large car along a track to a speed of 150 miles per hour. A hydraulic jet catapult seems to be the best-suited for the purpose, and various types of design problems are examined.

Memorandum presenting a method for designing a wing to be self-trimming at a given set of flight conditions. The spanwise distribution of load on the wing is made to be approximately elliptical, in an effort to maintain low wing drag. The procedure is illustrated using several examples.

Report presenting some highlights of recent experimental studies of flutter at high speeds. Flutter problems have become more varied with the advent of transonic flight and importance of aeroelasticity, and the flutter field has merged with other aspect of aeroelasticity such as divergence and buffeting. The two main subjects of flutter, classical flutter and stall flutter, are explored in these studies.

"An experimental investigation of a 0.8 hub-tip radius ratio, nontwisted-rotor-blade turbine designed for a stagnation-pressure ratio of 2.5 and an equivalent mean blade speed of 643 feet per second was made in a cold-air turbine with (a) nontwisted stator blades, and (b) twisted stator blades designed to maintain zero rotor-inlet incidence angles. Turbine efficiencies of the order of 0.85 at the design point were obtained with a nontwisted-rotor-blade turbine with a hub-tip radius ratio of 0.80. The turbine with the twisted stator blades gave higher efficiencies at the design point (of the order of 1.5 percentage points) than the turbine with the nontwisted stator blades" (p. 1).

"The pressure distribution and drag were determined for a spherical-nosed axially symmetric body with thin projecting rods at Mach numbers of 1.76, 1.93, and 2.10. The upstream projection distance of the rods was varied over a wide range to study changes in the character of the flow separation and to determine the variation of drag and pressure distribution with tip projection. Drag coefficients between 0.18 and 0.30 were obtained for most tip projections at each Mach number" (p. 1).

Report presenting the effects of Mach number between 0.50 and 0.95 and between 1.09 and 1.29 on the characteristics of the downwash and on the location of the wake behind a triangular wing of aspect ratio 4 as determined from semispan model tests.

Memorandum presenting an investigation on the effectiveness of different slot configurations, which uses the method of making the flow of the cooling air visible. Two methods were used for this purpose: one utilized the traces caused by a reaction between pain spread over the blade surface and a gas mixed with the cooling air, while the second utilized smoke mixed with the cooling air to make it visible. A continuous slot was found to give the best coverage of the cooling-air film.

Report presenting a wind-tunnel investigation of two semispan wing models with 45 degrees of sweepback, an aspect ratio of 5, and a taper ratio of 0.565. One wing had no camber or twist while the other was cambered for a design lift coefficient of 0.4 and twisted to relieve loading at the tip. Results regarding the plane wing, cambered and twisted wing, wing-body combinations, effect of camber and twist, effect of fences, effect of surface roughness, and lift-drag ratio are provided.

From Introduction: "The investigation reported herein, which was conducted in an NACA Lewis altitude test chamber, covered a range of altitudes from 30,000 to 50,000 feet at a flight Mach number of 0.8."

An investigation was conducted to determine the behavior of recently produced, forged S-816 turbine blades in a full-scale turbojet engine, and in particular, the scatter in performance of the alloy. The turbine blades were operated as continuously as possible at a temperature of 1500 degrees F and a centrifugal stress of 21,500 pounds per square inch. The operating lives of the turbine blades varied from 181 to 539 hours, a range of 358 hours. Stress-rupture properties of specimens cut from blade airfoils also varied considerably, as much as 1257 hours at 20,000 pounds per square inch and 1500 degrees F. Since the variability of scatter of stress-rupture data is greater than that of blade performance, the scatter is probably caused by variations in the properties of the forged blades rather than by variations caused by engine operation or installation of the blades. Metallographic examinations were made to determine possible causes of the scatter and although numerous differences in microstructures of blades were found, no consistent tendencies were observed and the findings did not permit an explanation of the scatter of blade performance. The results of the metallographic examinations and of the physical tests indirectly indicated variables in the fabricating method …

Report presenting an investigation to determine the effects of six stabilizing fin plan forms and three body-nose configurations on the static stability of a 20 degree cone-cylinder body of revolution that had a fineness ratio of 8.65. The fin plan forms tested were swept untapered fins with 45 and 60 degrees sweep angles, trapezoidal fins, and delta fins. Results regarding the normal force coefficient, pitching moment coefficient, and center of pressure are provided.

Report presenting thrust-reversal performance of several basic target-type jet reflectors of various sizes and with various modifications obtained with unheated air over a range of exhaust-nozzle pressure ratios. Maximum, or near maximum, reversal for any deflector occurred at a spacing which was mechanically feasible and did not affect nozzle air flow.

Report presenting an experimental investigation in the 8- by 6-foot supersonic wind tunnel to determine the performance characteristics of a twin-duct side intake system joining into a common duct and utilizing two-dimensional 6 degree compression ramps mounted on a supersonic airplane at Mach numbers 1.5 and 1.7.

"A method is presented for estimating the rolling moments caused by wing-tail interference for missiles composed of wing-tail-body combination. The considerations involved in determining the structure of the downwash field behind lifting cruciform wing-body combinations and the rolling moment on cruciform wings of various plan forms induced by an infinite line vortex are discussed in detail. Computations of induced rolling moments for several missile designs are compared with experimental results" (p. 1).

An investigation of the performance of a twin-duct air-intake system with a 9 degree compression-ramp inlet mounted on a supersonic airplane in the 8- by 6-foot supersonic wind tunnel at a range of Mach numbers, angles of attack, yaw, and mass-flow ratios. The effect on performance of a series of boundary-layer-removal wedges and a main-duct airflow bypass system were also investigated.

Report presenting an investigation in the flutter research tunnel to determine the oscillating forces and moments on a two-dimensional wing equipped with an oscillating circular-arc spoiler. The study indicated that force and moment coefficients and their phase angles are affected by Reynolds number, Mach number, and reduced frequency.

From Introduction: "Reported herein are the over-all engine performance and the starting and windmilling characteristics. Data are presented in the form of performance maps at each flight condition to show the effects of altitude and flight Mach number on various engine-performance variables. The effect of engine deterioration with operating time on performance is also discussed."

From Summary: "A compilation has been made of available information on the problem of support interference at transonic and supersonic speeds. This compilation indicates that at supersonic speeds there are sufficient experimental data to design properly sting supports and shrouds having negligible interference. At transonic speeds the interference problem becomes more acute, and more experimental information is needed."

Report presenting an investigation to determine the effect of spanwise variations in thickness ratio on the aerodynamic characteristics of wings at transonic speeds. Lift, drag, and pitching-moment data rare presented for 3 wings with different taper ratios. Testing occurred over a range of Mach and Reynolds numbers.

From Summary: "An experimental investigation of a series of four convergent-divergent exhaust nozzles was conducted in the Lewis 8-by-6 foot supersonic wind tunnel at Mach numbers of 0.1, 0.6, 1.6, and 2.0 over a range of nozzle pressure ratios. The thrust characteristics of these nozzles were determined by a pressure-integration technique. From a thrust standpoint, a nozzle designed to give uniform parallel flow at the exit had no advantage over the simple geometric design with conical convergent and divergent sections."

Report presenting the aerodynamic design and design-point performance of a 16-inch impulse-type supersonic-compressor rotor component with turning to the axial direction, including an off-design and stage performance analysis. Results regarding rotor component performance, discussion of rotor performance, stage consideration for rotor performance, stage performance, and stator performance are provided.

Report presenting an experimental investigation in the altitude test chamber on an axial-flow turbojet engine at transonic flight conditions to determine the magnitude of thrust augmentation and to ascertain the operational characteristics of a combined augmentation system. Results regarding the augmented engine performance, influence of coolant on afterburner combustion, performance losses, and operational problems are provided.

The adhesive and protective characteristics of National Bureau of Standards Coating A-417 were investigated, as well as the effect of the coating on the life of forged Refractaloy 26 and cast Stellite 21 turbine blades. Coated and uncoated blades were run in a full-scale J33-9 engine and were subjected to simulated service operations consisting of consecutive 20-minute cycles (15 min at rated speed and approximately 5 min at idle). The ceramic coating adhered well to Refractaloy 26 and Stellite 21 turbine blades operated at 1500 degrees F. The coating also prevented corrosion of the Refractaloy 26, a corrosion-sensitive nickel-base alloy, and of the Stellite 21, a relatively corrosion-resistant cobalt-base alloy. Although the coating prevented corrosion of both alloys, it had no apparent effect on blade life.

Report presenting an investigation of wings of aspect ratios of 4, 3, and 2 with a plan-form taper ratio of 0.5 and a thickness taper ratio of 0.33 to determine their transonic longitudinal characteristics and effects of tapering thickness ratio. Results regarding the combined effects of aspect ratio and thickness ratio and effects of tapered thickness ratio are provided.