Report presenting an investigation to determine which of two ceramic coatings, L-7C and A-417, developed by the National Bureau of Standards is more suitable as a protective coating for turbine blades in a turbojet engine. Four cast Vitallium turbine blades, two coated with each of the ceramics, were installed in a turbine wheel of a turbojet engine and subjected to accelerated cyclic life tests.

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.

Results of a wind-tunnel investigation at a Reynolds number of 6.8 x 10(exp 6) to determine the static longitudinal stability characteristics of a 42 degree sweptback wing and fuselage combination with a sweptback horizontal tail are provided. Included are the effects of vertical position of fuselage and tail with respect to wing for several combinations of high-lift and staff-control devices. Also included is the effect of a simulated ground.

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.

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 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.

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.

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 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 tank results for take-off tests with a powered dynamic model of a hypothetical jet-propelled high-speed airplane fitted with NACA hydro-skis and with flush turbojet intakes on the upper part of the fuselage near the nose. Some of the investigations included were the possibility of making take-offs without spray entering the intakes, the effect of turbojet air inflow on the tendency of spray to enter the intakes, and the effect of jet power on trim.

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."

Report presenting wind-tunnel measurements of the pressure distribution on a semispan wing with a modified NACA 0012-64 airfoil section and a plain trailing-edge aileron with the wing unswept and also swept back 45 degrees. Adverse changes in loading and loss of aileron effectiveness developed with the wing unswept as the Mach number was increased, but did not occur at Mach numbers up to 0.925 with the swept wing. Results regarding section characteristics and effect of fences are provided.

From Summary: "Ogive-cylindrical fuselages of fineness ratio 11 have been flight-tested with and without stabilizing fins. Base-pressure measurements over a range of free-stream Mach numbers from 0.7 to 1.3 indicated that the fins reduced the base drag. A rear-support sting similar to those used in wind tunnels was tested with one of the fuselages and found to reduce base suction by 40 percent at subsonic speeds, but to have little effect at Mach numbers above 1.15."

Report presenting an investigation of the performance of several conical cooling-air ejectors at primary jet pressure ratios from 1 to 10, secondary shroud pressure ratios from 0.60 to 4.00, and primary to secondary temperature ratio of 1.0. The investigation centered on primary air flow, secondary air flow, primary nozzle thrust, and gross ejector thrust.

Report presenting testing of JP-3 fuel and a slurry of 60 percent powdered magnesium in JP-3 fuel in a small-scale afterburner in the presence of large quantities of water vapor. The results indicated that total temperature, combustion efficiency, and air specific impulse were improved when the magnesium slurry was used, but the improvements came at the cost of increased liquid consumption.

Report presenting an analytical and experimental evaluation of diborane as a ram-jet fuel, which seems to offer greater flight range, thrust, and combustion stability beyond what is attainable with petroleum fuels. Results regarding ideal thrust, stability, deposits, and flight range with several blends of diborane are provided.

Report presenting an investigation of some effects of aileron spanwise location and wing structural rigidity on the rolling power of 0.3-chord plain, flap-type ailerons on a wing with a taper ratio of 0.25, an aspect ratio of 3.5, and swept back 63 degrees at the leading edge. Results regarding the aeroelastic effects and aileron span and spanwise location are provided.

Report presenting an investigation in the free-flight tunnel to determine the dynamic longitudinal stability and control characteristics of tandem-coupled bomber-fighter airplane models. Results regarding bomber alone tests, freely coupled combination, and rigidly coupled combination are provided.

An investigation was conducted to study the mechanisms of blade failure of forged Hastelloy B and cast Stellite 21. The blades were mounted in a 16-25-6 alloy rotor and subjected to 20-minute cycles consisting of 15 minutes at rated speed and approximately 5 minutes at idle. The first failures of the Hastelloy B and Stellite 21 blades were probably the result of excessive vibratory stresses and occurred after 14.25 and 16.75 hours, respectively. After 28.75 hours of operation, all but 3 of the original 25 Hastelloy B blades had either failed or contained stress-rupture-type cracks and four of the original 27 Stellite 21 blades contained stress-rupture-type cracks.

Memorandum presenting the results of an experimental investigation to determine the effects of Reynolds number on the flow characteristics over a delta wing at a Mach number 2.41. The wing streamwise airfoil sections are based on the NACA 00-thickness series with the maximum thickness varying from 4 percent at the root section to 6.24 percent at the 90-percent spanwise station. Results regarding force data and pressure-distribution data are provided.

Report presenting the low-speed lateral control and hinge-moment characteristics of a 20-percent-chord plain aileron on a 47.7 degree sweptback wing of aspect ratio 5.1 in the pressure tunnel. The tests were performed with and without high-lift and stall-control devices. Results regarding the basic aileron data, rolling-moment characteristics, and pitching-moment characteristics are also provided.

Report presenting an investigation of the effect of Reynolds number and the addition of leading-edge roughness on the aerodynamic characteristics of wings with aspect ratio 1, 2, and 3, a rectangular plan form, square-cut wing tips, and NACA 0012 airfoil sections. Results regarding lift and moment, lift-curve slope, and maximum lift are provided.

Report presenting longitudinal-damping data in the form of the pitching-moment derivatives and summarized from flight tests of rocket-propelled models and full-scale airplanes. 22 models and 4 airplanes are examined in the study and the damping derivative results are generalized.

"The experimental performance of a modified turbine for driving a supersonic compressor is presented and compared with the performance of the original configuration to illustrate the effect of small changes in the ratio of nozzle-throat area to rotor-throat area. Performance is based on the performance of turbines designed to operate with both blade rows close to choking. On the basis of the results of this investigation, the ratio of areas is concluded to become especially critical in the design of turbines such as those designed to drive high-speed, high-specific weight-flow compressors where the turbine nozzles and rotor are both very close to choking" (p. 1).