Results are presented from a hydrodynamic investigation of the inception of vortex ventilation on modified-flat-plate rectangular lifting surfaces of aspect ratio 0.25 differing in scale and thickness ratio. Two types of bubble-formation processes are described. Inception speeds were correlated for bubble formation in the high angle-of-attack range by using the Froude number and for that in the low angle-of-attack range by expressing the speed as a function of the thickness ratio.

Results of an investigation of the hydrodynamic characteristics over an extended speed range of a rectangular modified flat plate having an aspect ratio of 0.25 and operating at several depths of submersion are presented. Comparisons between these data and data over a lower speed range on a similar aspect-ratio-0.25 flat plate but having one-half the thickness are presented. These comparisons show no significant differences at the low speeds. At high speeds and high angles of attack, where extensive cavitation was present, the lift coefficients were lower than would have been indicated by the results of the previous investigations and the present investigation at the lower angles of attack. A brief discussion and comparison of ventilation are presented which shows two types of planing bubble formation and the effect of increasing the thickness of the model on the ventilation boundary.

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).

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.

"Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is included to the flow. Errors due to variations in the configuration of static-pressure vents are also presented" (p. 1).

Memorandum presenting a preliminary and theoretical investigation of the effect of velocity diagram on inlet total-pressure distortions through single-stage subsonic axial-flow compressors for incompressible flow. A theoretical investigation was used to determine proper velocity diagrams and then the wake of a 1/4-inch-diameter rod was measured upstream of the rotor. The tests indicated that the derived equation will estimate the downstream distortion with reasonable accuracy for inlet total-pressure distortion which extends far enough circumferentially to alter the static-pressure field in the blade passage.

Memorandum presenting an 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.

Report 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. Combustion with hydrogen was found to be stable up to the facility altitude limit of 89,000 feet.

Report presenting an investigation to determine the control hinge-moment characteristics at two Mach numbers for a series of 18 controls, including the effects of various tabs and fences, on a 60 degree delta wing. Testing covered a range of angles of attack, control deflection, and tab deflection. Results regarding the basic variation of hinge-moment coefficients, tip controls, and trailing-edge controls are provided.

Report presenting testing of a transonic compressor rotor with double-circular-arc blade sections and inlet guide vanes turning counter to the direction of rotor whirl to determine the effect of blade-row interaction on the performance of a transonic rotor. Results regarding overall performance, guide-vane performance, rotor-inlet conditions, rotor-outlet conditions, consideration of radial equilibrium, blade-element performance, and axial asymmetry in rotor-outlet flow are provided.

Memorandum presenting an investigation of the static longitudinal stability characteristics of two wings of different construction and slightly different flexibilities in the 16-foot transonic tunnel. The wings had the same external dimensions but one had a steel construction and the other was made of plastic reinforced by a steel core.

Memorandum presenting an investigation conducted in the 7- by 10-foot tunnel of the static longitudinal and lateral stability characteristics of a model with a 45 degree sweptback wing of aspect ratio 4 and with several different tail arrangements. The tail configurations studied had unswept, rectangular surfaces and included a T-tail and conventional fuselage-mounted horizontal and vertical tails. Results regarding wing-fuselage characteristics, effects of afterbody shape, effect of tail configuration on stability, and comparison of swept- and unswept-wing configurations are provided.

Memorandum presenting an investigation in the 20-foot free-spinning tunnel on a 1/25-scale model of the McDonnell F3H-2N airplane. The effects of control settings and movements on the erect and inverted spin and recovery characteristics of the model were determined for the clean condition. Results regarding erect spins, engine gyroscopic moments, inverted spins, spin-recovery parachute, and landing condition tests are provided.

Report presenting flight tests on an FJ-3 airplane to determine the flight characteristics of a carrier-type airplane with area-suction and blowing boundary-layer control on the trailing-edge flaps. Measurements were made of lift, drag, and bleed-air requirements for the different types of boundary-layer control systems. Results regarding lift, drag, flow requirements, performance, pilots' opinions, and approach-speed criteria are provided.

Report presenting a review of the literature on the thermodynamic and physical properties of boric oxide. Data on the following properties is presented: specific heat, sensible enthalpy, total enthalpy, entropy, latent heat of vaporization, and vapor pressure for the crystal, liquid, and vapor states.

Report presenting an experimental investigation conducted to determine the lateral-directional aerodynamic characteristics at transonic speeds of missile configurations with three blunted cone-cylinder bodies. Modifications of the basic model were tested to determine the effects of relative lengths of the bodies and the effects of seals between the cylindrical parts of the bodies. Cross-wind force, drag, yawing moment, and rolling moment were measured through a range of angles of sideslip, angles of attack, and Mach numbers.

Report presenting a five-degree-of-freedom analysis of aircraft maneuvering stability, which showed that gyroscopic moments due to engine rotor momentum produced considerable rolling asymmetry for certain values of stability derivatives and flight conditions. Results regarding the altitude effects, Mach number effects, initial load factor, effective dihedral, static stability, roll velocity, and comparison with simplified longitudinal- and lateral-mode theory are provided.