Report presenting performance tests of thermal ice-prevention equipment designed and installed in the XB-24F airplane in icing and non-icing conditions. The recorded temperature and air-flow data, and the calculated quantities of heat flow throughout the system are presented in tabular form.

Report presenting an investigation of an 18-foot-radius helicopter rotor powered by tip-mounted ramjet engines in the helicopter test tower. The engine performance is compared with the performance determined in a previous investigation of a 9-foot-radius rotor with the same engines at similar speeds but with twice the centrifugal forces. Results regarding the propulsive characteristics, minimum specific fuel consumption and corresponding propulsive thrust, and operational characteristics are provided.

"Two short turbojet combustors designed for use with vaporized hydrocarbon fuels were tested in a one-quarter annular duct. The experimental combustors consisted of many small "swirl-can" combustor elements manifolded together. This design approach allowed the secondary mixing zone to be considerably reduced over that of conventional combustors" (p. 1).

From Summary: "The results of force tests made at low speed are presented to show the effect of longitudinal static stability produced by drooping the tip of a 63 degree sweptback wing. Five semispan wing models were tested: two incorporated curved drooped tips, two with abruptly drooped tips, and one without droop. The most favorable stability characteristics were measured for a model with an abruptly drooped tip, a fence, and a leading-edge flap; however, the use of these same auxiliary devices on the undrooped wing was nearly as effective."

Report presenting flight tests to measure the directional stability of a fighter-type airplane over a range of Mach numbers. Testing occurred at two altitudes and used three vertical tails of varying aspect ratio or area.

Report presenting an examination of the use of an axisymmetric variable-geometry technique for achieving good supersonic inlet performance over a wide range of Mach numbers. An inlet with a telescoping spike was designed and experimentally evaluated. Results regarding the spike survey study and variable-geometry-inlet study are provided.

Performance characteristics of a 16-inch annular-type combustor installed in a full-scale engine using gaseous-hydrogen fuel were obtained at simulated altitudes from 66,000 to 86,000 feet at a flight Mach number of 0.8. Combustion efficiencies of 86 percent were obtained at 86,000 feet (combustor pressure, 420 lb/sq ft abs). Combustor blowout was not encountered during the investigation.

Report presenting an experimental investigation at Mach number 1.90 to determine the overall performance capabilities of axisymmetric two-cone and isentropic nose inlets in terms of total-pressure recovery, mass flow, and external drags. At zero angle of attack, the external drag was separated into their components of cowl pressure, friction, and additive drags. Results regarding total-pressure recovery and mass-flow characteristics, total-pressure profiles at diffuser exit, cowl-pressure distributions and drag, zero-angle-of-attack component breakdown of external drag, and overall performance comparison are provided.

Report presenting a centrifugal impeller with a modified design procedure to reduce the velocity gradients existing along the hub from inlet to outlet. The modified impeller had better performance characteristics than the original at all speeds tested.

From Summary: "The effect of engine momentum on the longitudinal and directional stability of aircraft in steady rolling maneuvers has been investigated. The results presented indicate that the gyroscopic moments produced on the aircraft by rotating engine in rolling maneuvers can have an appreciable effect on the range of rolling velocities for which longitudinal or directional instability might occur."

Report presenting an analysis made to permit a comparative evaluation of the turbine rotor cooling-air requirements with convection-cooled blades for four combustor-outlet radial gas-temperature profiles: a uniform profile, a profile representable by a complete cycle of the cosine wave using cooler gas layers near the turbine casing, a profile representable by one-half cycle of the cosine wave using cooler gas layers near the stator inner ring, and an optimum profile resulting in the absolute minimum cooling-air requirements.

Effective flame speeds of free turbulent flames were measured by photographic, ionization-gap, and photomultiplier-tube methods, and were found to have a statistical distribution attributed to the nature of the turbulent field. The effective turbulent flame speeds for the free flame were less than those previously measured for flames stabilized on nozzle burners, Bunsen burners, and bluff bodies. The statistical spread of the effective turbulent flame speeds was markedly wider in the lean and rich fuel-air-ratio regions, which might be attributed to the greater sensitivity of laminar flame speed to flame temperature in those regions. Values calculated from the turbulent free-flame-speed analysis proposed by Tucker apparently form upper limits for the statistical spread of free-flame-speed data. Hot-wire anemometer measurements of the longitudinal velocity fluctuation intensity and longitudinal correlation coefficient were made and were employed in the comparison of data and in the theoretical calculation of turbulent flame speed.

Report discussing an investigation of the effect of curved speed brakes on the drag characteristics and longitudinal stability and control characteristics of a model of the MX-1554A with a circular jet nozzle. The speed brakes were tested at several deflections, gaps, and locations in the landing configuration and clean configuration. Results of a lateral- and directional-stability study due to reduction in the vertical tail area are also provided.

Memorandum presenting tests conducted with four specific versions of a swept-wing fighter airplane, which indicate that a large reduction in external-drag coefficient was accomplished by redesigning the original configuration. The forebody modifications, which consisted of a smaller canopy, slimmer nose, and sharper inlet lip, reduced the value of the external-drag coefficient from 0.044 to 0.042 at a Mach number of 1.05 and from 0.042 to 0.040 at a Mach number of 1.28.

Report discussing an experimental investigation of the low-speed rolling stability derivatives of a model of the Douglas A4D-1. The model was tested under a variety of conditions, including in clean and landing configurations and with the horizontal and vertical tails on and off, and the study also explored the effects of slats and flaps on the derivatives of the wing. No analysis of the data is provided.

Memorandum presenting an investigation of the problems associated with the design of a low-pressure-loss, short afterburner for sea-level thrust augmentation in a static, sea-level test stand. Results regarding diffuser pressure losses, afterburner pressure losses, and afterburner performance are provided.

"An investigation was conducted at the NACA Lewis laboratory to obtain pressure-drop data for flow of air with no heat addition through mockups of two reactor segments of the proposed General Electric Company aircraft reactor. Pressure-drop data were obtained over a range of Reynolds numbers from 4000 to 80,000, air inlet Mach numbers from 0.02 to 0.40, inlet pressures up to about 40 inches of mercury absolute, and ambient air temperatures. factors, corrected for entrance, vena contracta, momentum, and exit losses, are considerably higher at the high Reynolds numbers than those reported for turbulent flow in smooth pipes" (p. 1).

Report presenting the results of an investigation at supersonic speeds to determine the aerodynamic characteristics of a model of the North American MX-770 missile at several designated Mach numbers. No analysis is provided. Information about the longitudinal aerodynamic characteristics with trimmer and elevon deflected and lateral aerodynamic characteristics are described.

Report discussing an investigation of the stability of a series of flared-body and blunted-cone models at a range of Mach numbers. Increasing the flare length was found to increase static stability and the damping in pitch. The Reynolds number was found to have a large effect on static stability at lower Mach numbers, but little effect on the higher end of the range covered in testing.

Memorandum presenting the results of recent exploratory investigations of the performance of clustered jet-exit installations at Mach numbers from 0.60 to 3.05. Data presented in this report were obtained with tunnel-wall-mounted models with cold-air-jet exhaust. Results regarding base pressures, effect of boattailing, effect of afterbody-nozzle geometry, and terminal fairings are provided.

Memorandum presenting a single J33 combustor and an experimental tubular combustor incorporating a fuel vaporizer as operated with gaseous hydrogen at temperatures slightly above the boiling point of the fuel. Data were obtained to explore possible effects of the fuel temperature on combustor performance and on the control and measurement of fuel flow.

Report presenting a flight investigation on a roll-stabilized ramjet test vehicle to determine engine performance over a range of Mach numbers, a range of fuel-air ratio, and an altitude range. Results regarding engine performance and roll autopilot performance are provided.

Memorandum presenting a study of the static stability and control problems associated with several hypersonic boost gliders. Generally, it is possible to obtain the desired trim features. Results regarding the high-lift-drag-ratio type of gliders and low-lift-drag-ratio type of gliders are provided.

Memorandum presenting an investigation of the performance of a semielliptical scoop inlet with a two-dimensional flow field at the design Mach number of 2.0. The investigation included a study of the effects of inlet-leading-edge shape and boundary-layer bleed on the pressure recovery and total-pressure distribution. Results regarding performance of inlets without boundary-layer bleed, effect of diverter boundary-layer bleed, effect of leading-edge sweep angle, effect of compression-surface bleed, performance of inlet III-B, tests of buzz suppressors, and tests of rearward-facing control tubes are provided.