Memorandum presenting an investigation of the flow characteristics over a 6-percent-thick symmetrical circular-arc airfoil section with a 30-percent-chord trailing-edge flap at a Mach number of 6.90 and a Reynolds number of 1.65 x 10(sub 6). The model was tested over an angle-of-attack range of 0 to 16 degrees and a flap-deflection range of -16 degrees to 16 degrees. Results regarding pressure results and aerodynamic characteristics are provided.

Attenuation of tangent-pressure oscillation in liquid-oxygen-heptane rocket engine combustion chamber using longitudinal fin. Results regarding the engine performance with injector A, effect of fins with injector A, and destructiveness of screaming are provided.

An investigation of the use of fins to prevent high-frequency combustion-pressure oscillations (screaming) in the combustion chamber of a 1000-pound-thrust rocket engine with a chamber pressure of 300 pounds per square inch and using liquid oxygen and n-heptane as propellants. Tangential combustion-pressure oscillations were found to be eliminated with longitudinal fins located in the combustion zone. Results regarding engine performance, effect of fins, and destructiveness of screaming are provided.

Memorandum presenting an annotated bibliography of NACA reports containing information of interest to designers and manufacturers of controls for turbojet engines. The eleven major topics include starting, acceleration, flame-out, temperature control, stability and dynamics of small disturbances, combustion dynamics, engine inlet diffuser control, steady-state engine performance, fuel systems, sensors, and general control system theory.

Report presenting pressure-drag coefficients and the changes in these coefficients with mass-flow ratio, which have been measured in tests of six open-nose conical cowls at an angle of attack of 0 degrees. Testing occurred in the Ames 8 by 8-inch supersonic wind tunnel at a range of Mach numbers. Results regarding pressure distributions, change in cowl pressure drag with mass-flow ratio, cowl pressure drag at a given mass-flow ratio, and changes in cowl pressure drag with mass-flow ratio as a function of Mach number are provided.

"A ditching investigation was made of a l/l2-scale dynamically similar model of the Douglas F4D-1 airplane to study its behavior when ditched. The model was landed in calm water at the Langley tank no. 2 monorail. Various landing attitudes, speeds, and configurations were investigated. The behavior of the model was determined from visual observations, acceleration records, and motion-picture records of the ditchings. Data are presented in tables, sequence photographs, time-history acceleration curves, and attitude curves" (p. 1).

"An investigation has been conducted in the 27- by 27-inch preflight jet of the Langley Pilotless Aircraft Research Station at Wallops Island, Va., of the release characteristics of a dynamically scaled streamlined-type internally carried store from a simulated bomb bay at Mach numbers M(sub o) of 0.8, 1.4, and 1.98. A 1/17-scale model of the Republic F-105 half-fuselage and bomb-bay configuration was used with a streamlined store shape of a fineness ratio of 6.00. Simulated altitudes were 3,400 feet at M(sub o) = 0.8, 3,400, and 29,000 feet at M(sub o) = 1.4, and 29,000 feet at M(sub o) = 1.98" (p. 1).

Memorandum presenting a generalized analysis of a pressure-jet powerplant. The effect of changes in ambient conditions on the powerplant performance is provided in a series of charts using parameters containing temperatures and pressures. Some of the variables investigated included the pressure-jet powerplant performance in helicopter and pressure-jet-helicopter performance.

Report presenting data from which the effects of transpiration air flow on average skin-friction coefficients and pressure drag of a conical model were evaluated. The model consisted of a truncated porous nose cone with a solid ogival nose section. Results regarding the pressure distribution, base pressure drag, average skin-friction coefficients, effects of transpiration air, and comparison with theory.

Report presenting the tendencies of 14 different fuels and three fuel blends to produce high-frequency oscillatory combustion (screaming) in a 200-pound-thrust, water-cooled, liquid-oxygen-fuel rocket engine. The fuels, in order of increasing screaming tendency, were hydrazines, branched-chain paraffins, aromatics, and amines, and straight-chain paraffins. Results regarding screaming tendency and screaming amplitude are provided.

Memorandum presenting the subsonic and transonic longitudinal handling qualities of the Douglas D-558-II research airplane with several wing modifications designed to alleviate swept-wing instability and pitch-up. The airplane configurations investigated included the basic wing configuration and two wing-fence configurations in combination with retracted, free-floating, or extended slat,s and a wing leading-edge chord-extension configuration.

Report presenting an investigation of three phases: an experimental investigation of a thin airfoil with blowing over a trailing-edge flap, a comparison of the results of the experimental investigation with the results of other similar investigations, and a theoretical study of the relationships among the air-flow and power parameters for the general blowing case. The investigation utilized a two-dimensional model of the NACA 0006 airfoil equipped with a nose flap and six alternate trailing-edge flaps.

Report presenting an acceleration control that operates on fuel flow and uses directly measured acceleration as the control signal as applied to an axial-flow turbojet engine. A study to determine the feasibility and dynamic characteristics of the control was undertaken. Results regarding the open-loop characteristics and closed-loop characteristics are provided.

Report presenting testing of a 4.5 inch by 4.5 inch tunnel with slots in two opposite walls in order to determine the effects of various slot exit shapes, mixing sections, and diffusers on power requirements. Some of the data obtained included measurements of the pressure ratio required to operate the tunnel, the effects of auxiliary bleed flow, diffuser static-pressure ratios and distributions, and diffuser total pressure distributions.

Report presenting an investigation in the 8- by 6-foot supersonic tunnel to determine the external-stream effects on the gross thrust and pumping characteristics of ejectors operating at off-design Mach numbers. Results regarding the pumping, thrust, and base characteristics, boattail drag characteristics, and stream effects on jet thrust for typical ejector installations are provided.

Memorandum presenting an investigation to devise an air-cooled turbine blade which eliminated the difficulties encountered with brazing in air-cooled-blade fabrication. Techniques were developed for casting air-cooled blades with a large number of relatively small cooling passages near the airfoil surface; two such blades of HS-21 material were operated in a turbojet engine modified for air cooling. Results regarding the heat-transfer characteristics, stress and durability results, and evaluation of cast-cored-blade potential are provided.

"Flight tests of fifteen T-231 70-mm HEAA rocket projectiles (flight components of the T-263 HEAA rounds) were made at the Langley Pilotless AIrcraft Research Station at Wallops Island, VA., to obtain flight trajectories at high quadrant elevation launchings and to obtain drag data. Although all rounds were of the same general type, there were differences in nozzle cant angles, number of nozzles per round, shape of head and fuse, motor case length, and type of propellant. All projectiles were launched at an elevation angle of 60 deg" (p. 1).

Report presenting the zero-lift drag of several wings obtained at supersonic Mach numbers in free flight with rocket-propelled models. The wings tested all had the same exposed area, mounted on the same basic body configuration, and had one of four different types of wings.

Memorandum presenting an investigation of a full-scale afterburner with high burner-inlet velocity conducted to determine burner performance with several variations in burner design. Variables receiving particular attention were flameholder design and burner length. Results regarding diffuser performance, performance of the reference two-V-gutter flameholder, designs to improve combustion for high-velocity conditions, and operational characteristics are provided.

Report presenting an investigation of a full-scale afterburner with high burner-inlet velocity to determine burner performance with several variations in burner design. A total of 12 flameholder configurations were investigated at a specified burner-inlet velocity and a range of burner-inlet pressures. Results indicated that a basic annular two-V-gutter flameholder can operate at 90 to 95 percent combustion efficiency for fairly optimum burner length and pressure.

Report presenting a study of injection principles for liquid oxygen and heptane made with two-element injectors, as the previous study only included single-element injectors. Eight injectors, produced by two spray orientations of each of the four injection processes, were investigated. Results regarding atomization after mixing, atomization before mixing, atomization without mixing, fuel atomization without mixing, and overall comparisons of the injectors are provided.

Report discusses the results of an investigation of a model of a wing of 45 degree sweepback and aspect ratio 6 to determine the aerodynamic characteristics and suction requirements for boundary-layer control by means of area suction applied to trailing-edge flaps. Various flap spans and flap deflections were tested. The measured values of the coefficients were compared to the calculated values.

Report presenting an investigation of the lateral stability and control effectiveness of a model of a fighter-type airplane model with a low-aspect-ratio and 3.4-percent-thick wing with negative dihedral at a range of Mach numbers, sideslip angles, and angles of attack. Results regarding the lateral characteristics at zero angle of attack, lifting conditions, and lateral and directional controls are provided.

Report presenting the longitudinal stability characteristics of a simple infrared homing missile determined in flight with a rocket-powered model. Static and dynamic longitudinal stability derivatives of the cruciform, interdigitated, canard-wing missile configuration were determined using the pulse-rocket technique for a range of Mach numbers.