Memorandum presenting various reports regarding the use of hydrogen for turbojet and ramjet powered flight. Some of the characteristics considered include the combustion properties, potential fueling problems, and flight experience with hydrogen on-board.

Memorandum presenting an investigation to determine the performance of the J65-B-3 turbojet engine with JP-4 and gaseous-hydrogen fuels. With JP-4 fuel, the maximum altitude for stable combustion was from about 60,000 to 65,000 feet, and the ultimate blowout limit was at an altitude of about 75,000 feet. The steady-state performance with either fuel decreased considerably with increasing altitude.

Report presenting a flight test of pentaborane fuel in an air-launched ramjet engine with a design free-stream Mach number of 1.8. The ramjet used in the investigation had a revised spray bar-flameholder configuration. Results regarding propulsive thrust and propulsive-thrust specific fuel consumption are provided.

Memorandum presenting an evaluation of the performance increase resulting from the addition of 20 percent fluorine to the oxygen-RP-1 propellant combination in a 5000-pound-thrust rocket engine at a chamber pressure of 650 pounds per square inch absolute. Runs were made with the engine water cooled and regeneratively cooled.

Memorandum presenting the results of an investigation directed at determining the effectiveness of various amounts and spanwise extents of conical camber on the aerodynamic characteristics of a wing-body-tail combination employing a triangular wing of aspect ratio 2.2. Five cambered wings were tested, all of which were designed for a Mach number of 1.0. Results regarding drag characteristics and lift and moment characteristics are provided.

Memorandum presenting an investigation at high subsonic speeds of a model of a twin-engine swept-wing fighter-type airplane. The model was tested with several different tail configurations and with several wing and engine inlet modifications. Results regarding pitching-moment characteristics, lift and drag characteristics, and lateral derivatives are provided.

Boundary-layer-transition and heat-transfer measurements were obtained from flight tests of blunt and sharp cones having apex angles of 50 deg. The test Mach number range was from 1.7 to 4.7, corresponding to free-stream Reynolds numbers, based on cone base diameter, of 18. 3 x 10(exp 6) and 32.1 x 10(exp 6), respectively. Transition on both models occurred at a local Reynolds number of 1 x 10(exp 6) to 2 X 10(exp 6) based on distance from the stagnation point. Transition Reynolds numbers based on momentum thickness were between 320 and 380 for the blunt cone. The model surface roughness was 25 rms microinches or greater. Turbulent heat transfer to the conical surface of the blunt cone at a Mach number of 4 was 30 percent less than that to the surface of the sharp cone. Available theories predicted heat-transfer coefficients reasonably well for the fully laminar or turbulent flow conditions.

Memorandum presenting the effect of missile armament on the performance of an interceptor-type aircraft model at Mach numbers 1.5, 1.7, and 1.9 and at angles of attack up to 19 degrees. The aircraft model was characterized by triangular-shaped normal-shock inlets located at wing roots. Results regarding force measurements, effect of armament on inlet-duct performance, fuselage boundary-layer survey, and total-pressure contours at inlet throat and diffuser exit are provided.

Report discussing a project to determine a high-energy fuel suitable for turbojet-powered aircraft. Components of the project include thermal and combustion properties, experiments with combustors using boron compounds, evaluation of boron fuels in full-scale turbojets with and without afterburners, and boron fuel use in ramjet flights. The most promising fuel found in the report is pentaborane.

Flight investigation of pentaborane fuel in 9.75- inch-diameter ramjet engine with downstream fuel injection.

Combustion efficiency of pentaborane fuel in 48- inch diameter ramjet engine.

"Skin temperatures and surface pressures have been measured on a slightly blunted cone-cylinder-flare configuration to a maximum Mach number of 9.89 with a rocket-propelled model. The cone had a total angle of 25 deg and the flare had a 10 deg half-angle. Temperature data were obtained at eight cone locations, four cylinder locations, and seven flare locations; pressures were measured at one cone location, one cylinder location, and three flare locations" (p. 1).

Report discussing the influence of forces and moments on a fighter-bomber airplane with an open bomb bay and on two bluff bomb shapes in various positions below the fuselage and plane of symmetry. The wing was found to have a noticeable effect on bomb forces and that bluff bombs affect the longitudinal characteristics of the wing-fuselage combination.

Memorandum presenting an experimental investigation of the cooling requirements and internal thrust performance of an air-cooled, plug-type, variable-area exhaust nozzle in a turbojet-engine afterburner over a range of exhaust-gas total temperatures and exhaust-nozzle pressure ratios.

From Summary: "A preliminary investigation was conducted to determine the altitude performance of pentaborane and a blend fuel of 64.2 percent pentaborane in JP-4 fuel in a tubular combustor of a current production type turbojet engine. Deposits on the liner barrel and dome were virtually nonexistent. The combustion efficiency of 90 to 94 percent for pentaborane and approximately 90 percent for the blend. Outlet temperature profiles were marginal; however, the developed combustor provided lower pressure losses than obtained in conventional combustors."

From Introduction: "Experimental investigations of the combustion characteristics of diborane, pentaborane, and pentaborane-hydrocarbon blends in modified turbojet combustors have been conducted at this laboratory at the request of the Bureau of Aeronautics, Department of the Navy, as part of Project Zip. Results of these single-combustor tests are presented in references 2 to 5."

Report presenting an investigation using a small-scale ramjet combustor to determine the conditions for spontaneous ignition of pentaborane, amyl nitrate, propylene oxide, and JP-4 fuel. For the range of conditions investigated, the threshold of spontaneous ignition of pentaborane is primarily governed by temperature and is also influenced by burner length and configuration. Combustion efficiency was found to increase in burner length and blocked area of the flame holder.

Report presenting testing of pentaborane as a fuel in a 48-inch-diameter ram-jet engine in a free-jet facility. Each test lasted about 50 seconds and used fast-response instrumentation and prescheduled fuel-flow variation for a range of fuel-air ratios. Results regarding combustion performance, ignition, oxide deposits, and fuel-injector performance are provided.

"An experimental radial-survey investigation of the J71-97 three-stage turbine equipped with a first stator having a throat area 87 percent of the design value was conducted at one turbine operating point. The first-, second-, and third-stage mass-averaged efficiencies were 0.897, 0.843, and 0.755, respectively. The corresponding over-all turbine efficiency was 0.856" (p. 1).

"Measurements of aerodynamic heat transfer have been made along the hemisphere and cylinder of a hemisphere-cylinder rocket-propelled model in free flight up to a Mach number of 3.88. The test Reynolds number based on free-stream condition and diameter of model covered a range from 2.69 x l0(exp 6) to 11.70 x 10(exp 6). Laminar, transitional, and turbulent heat-transfer coefficients were obtained" (p. 1).

Memorandum presenting an investigation of a swept-wing fighter-type airplane not equipped with an automatic pitch damper that made pulse maneuvers at altitudes from 10,000 to 40,000 feet over a Mach number range from 0.36 to 1.45 to determine the longitudinal stability characteristics and derivatives for an original-wing and an extended wing-tip configuration. Results regarding the original wing, extended wing, and influence of wing-tip extensions are provided.

Memorandum presenting a seven-part investigation of hydrogen for turbojet and ramjet powered flight. The combustion characteristics of hydrogen, in ramjets and afterburners, and in turbojet engines are described.

Report presenting detailed blade-element-performance plots for a high-flow transonic inlet rotor. Information provided includes the effects of Mach number, blade loading, and angle of attack on element performance is provided.

Report presenting testing of four models of a thin magnesium fin, with the leading edge swept back 35 degrees, of a type used to stabilize the first stages of rocket-propelled multistage hypersonic models. The investigation was carried out to determine some effects of aerodynamic heating at high stagnation temperatures on the leading edges of fins and to determine the relative effectiveness of several leading-edge protective methods. The fins tested included a basic fin, a fin with a blunt leading edge, a fin with a blunt leading edge wrapped with Inconel, and a fin with a blunt leading edge made of stainless steel.