Memorandum presenting rudder pulse maneuvers obtained with the Convair XF-92A delta-wing research airplane at an altitude of about 30,000 feet over a Mach number range of 0.52 to 0.92. Tests were made with and without a wing fence. By analyzing the maneuvers, the characteristics of the airplane transient, airplane stability derivatives, and frequency-response characteristics were measured.

From Summary: "A flight test has been conducted to determine the longitudinal stability and control characteristics of a 0.125-scale model of the McDonnell F-101A airplane for the Mach number range between 0.82 and 1.84. The variation of lift-curve slope with Mach number was gradual with a maximum value of 0.107 occurring at a Mach number of 0.95. The minimum drag coefficient (including base and internal drag) has a value of 0.020 at a Mach number of 0.87. The drag rise begins at a Mach number of 0.90, and at Mach number of 1.10 the minimum drag is 0.070. Above this Mach number there is a gradual increase in minimum drag coefficient to a value of 0.074 when the Mach number is 1.83."

Report presenting an investigation at Mach number 1.61 to determine the effect of 10-percent control are attached tabs on the hinge-moment characteristics of a trailing-edge flap-type control on a trapezoidal wing with a 23 degree sweptback leading edge, aspect ratio of 3.1, and taper ratio of 0.4. Results regarding hinge-moment coefficients, tab parameters, and control effectiveness are provided.

"A comparison is presented between the experimentally measured and theoretically calculated (by the method of NACA TN 3067) rates of roll of two rocket-propelled models with flexible rectangular wings. The comparisons show that although there are large aeroelastic losses in rolling rate, the theory predicts the actual rate of roll accurately" (p. 1).

Report describing an investigation conducted with a single combustor from a J47 turbojet engine using weathered aviation gasoline and several spark-plug modifications to determine altitude ignition, acceleration, and steady-state operating characteristics. Results regarding ignition, acceleration, altitude operational limits, combustion efficiency, and pressure loss are provided.

From Introduction: "Range in more or less steady level flight depends directly on aerodynamic lift-drag ratio at high supersonic speeds, just as it does at lower speeds. This result follows from the classical Breguet range equation in the case of powered flight, and it may be easily deduced from the equations of motion for unpowered or gliding flight (see refs. 1 and 2)."

Report presenting an investigation to study cowling-spinner combinations based on the NACA 1-series nose inlets and to obtain systemic data for one family of approximately ellipsoidal spinners. 11 of the spinners were also tested in various combinations with 9 NACA open-nose cowlings, which were also tested without spinners. Results regarding flow over spinners, internal flow, external flow over cowling, critical Mach number characteristics, envelope values, and cowling section are provided.

"In the present paper an analysis is made of the compressible-flow variations occurring in heat-exchanger passages. The results of the analysis describe the flow and heating characteristics for which specific flow passages can be treated as segments of generalized flow systems. The graphical representation of the flow variations in the generalized flow systems can then be utilized as working charts to determine directly the pressure changes occurring in any specific flow passage. On the basis of these results, working charts are constructed to handle the case of air heated at constant wall temperature under turbulent-flow conditions" (p. 1).

Tests were made to determine the loss in exhaust-jet thrust and engine power resulting from the insertion of an exhaust-gas-to-air heat exchanger in a jet-type exhaust stack of an aircraft engine. The thermal performance of the heat exchanger was also determined.

The durability of five different structural or cooling configurations or combination of both of air-cooled blades made of noncritical materials was investigated in a modified turbojet engine. The greater part of the investigation was conducted at an engine speed of 11,500 rpm, a turbine-inlet temperature of approximately 1670 degrees F, and a cooling-air to combustion gas flow ratio per blade of 0.05. The results of the investigation indicated that air-cooled blades made of noncritical metals can be operated for extended periods of time in engines at current inlet temperatures; however, before these blades are considered completely satisfactory for gas-turbine application, some means such as coatings is required to inhibit the oxidation of the blades.

Memorandum presenting the results of a wind-tunnel investigation of the damping in pitch of a model triangular wing with an aspect ratio of 4 combined with a slender pointed body. The investigation was conducted at Mach numbers from 0.10 to 0.95 for Reynolds numbers of 550,000 and 1,250,000 with additional data obtained at Reynolds numbers of 3,000,000 and 6,000,000 at Mach number 0.23. Results regarding the effects of oscillation amplitude, Mach number, Reynolds number, angle of attack, frequency, and pitching axis position are provided.

Report presenting a study and experimental investigation on the pressure rise across shock waves required to cause separation of the boundary layer on a flat plate. The interaction of shock wave and boundary layer was investigated experimentally when the boundary layer was caused to separate from the surface of a tube. Results regarding testing and correlation with other results are provided.

An investigation was made comparing the performance of JFC-2 fuel and unleaded, clear gasoline in a 3000-pound-thrust turbojet engine. The JFC-2 fuel was a blend of percent diesel fuel and 25 percent aviation gasoline. Engine combustion efficiency was equal to that obtained with gasoline at rated engine speed and altitudes up to 35,000 feet, but at lower engine speeds or at higher altitudes the JFC-2 fuel gave lower combustion efficiency. No discernible difference was obtained in starting or low-speed combustiion blow-out characteristics of the two fuels. Turbine-discharge radial temperature profiles were nearly the same at altitudes up to 35,000 feet.

The characteristics of a wedge static-pressure sensing element with various holder configurations were determined and compared with the characteristics of the conventional tube. The probes were tested over a range of Mach number from 0.3 to 0.95 and at various pitch and yaw angles. The investigation showed that the spike-mounted wedge sensing element has a pressure coefficient comparable with the conventional subsonic static-pressure probe and the pressure coefficient of the wedge varied less than that of the conventional probe for corresponding change of yaw angle.

Report presenting the results of an investigation to determine the effects of simulated skin wrinkling of the wing surface on the aerodynamic characteristics of two wing-body combinations. The lift, drag, and pitching moment of a low-wing wing-body combination with a plane triangular wing of aspect ratio 3 are presented for a range of Mach and Reynolds numbers.

From Summary: "Results of flight-path computations are presented for launchings from a straight deck and the curved ramp under conditions of insufficient lift at the instant of take-off."

From Summary: "Data are presented on the instrumentation and calibration technique used in determining the position error of angle-of-attack sensors mounted on the fuselage of a 35 degree swept-wing fighter airplane. The true angle of attack was determined by the use of a nose boom with five angle-of-attack vanes spaced 20 inches apart on alternate sides of the boom. Errors due to boom bending, upwash around the boom, and vane floating angle were measured and corrections applied to all indicated angles of attack."

Report presenting an investigation of flutter of wings mounted on the after portion of a body free to pitch was made in the flutter research tunnel. Uniform wings of 0 and 45 degrees sweep were tested at various positions rearward of the pitch axis. A low-frequency flutter was observed on the unswept wing, but no flutter was obtained for the swept wings.

From Introduction: "The purpose of the present paper is to investigate the effect of two-speed gearing on the take-off efficiency under certain conditions. The present paper gives charts from which the efficiencies can be readily computed for optimum rotational speeds. Also included is a brief discussion of the static thrust of thin propellers, including the effect of camber on the static thrust."

Report presenting a method for predicting the drag due to lift and lift-drag ratio of all-movable wing and body combinations and all-movable wings in the presence of bodies at supersonic speeds. The method is used to calculate the factors for configurations at which experimental data are available.

A wind tunnel investigation has been conducted to determine the steady-state windmilling and engine speed decay characteristics of the J34-WE-32 turbo-jet over a range of altitudes from 5000 to 50,000 feet and simulated flight Mach numbers from 0.19 to 1.06. The effect of an engine accessory load on the speed decay characteristics was also determined. The accessory load was about 7.8 horsepower for engine speeds above 4000 rpm and decreased with decreasing engine speed. An analysis of the speed decay data was made and engine speed decay rates were determined for hypothetical accessory loads up to 40 horsepower.

A spark energy of 2.13 joules per spark at 1 spark per second produced ignition to an altitude of 50,000 feet at a flight Mach number of 0.6. The minimum power requirements for ignition were obtained from a combination of low spark repetition rates and high spark energy. The altitude-ignition limit was also increased by increasing spark-gap immersion, fuel temperature, inlet-air temperature, and fuel volatility, and by decreasing flight Mach number. The maximum altitude at which flame propagation was accomplished from combusters with spark plugs to combusters without spark plugs to combustors without spark plugs was increased about 5000 feet by increasing fuel volatility.

"A multiple-range potentiometer circuit is described that provides automatic measurement of temperatures or temperature differences with any one of several thermocouple-material pairs. Techniques of automatic reference junction compensation, span adjustment, and zero suppression are described that permit rapid selection of range and wire material, without the necessity for restandardization, by setting of two external tap switches" (p. 1).

An investigation was made of the variation of the pressure limits of flame propagation with tube diameter for quiescent propane with tube diameter for quiescent propane-air mixtures. Pressure limits were measured in glass tubes of six different inside diameters, with a precise apparatus. Critical diameters for flame propagation were calculated and the effect of pressure was determined. The critical diameters depended on the pressure to the -0.97 power for stoichiometric mixtures. The pressure dependence decreased with decreasing propane concentration. Critical diameters were related to quenching distance, flame speeds, and minimum ignition energy.