"Wake development behind circular cylinders at Reynolds numbers from 40 to 10,000 was investigated in a low-speed wind tunnel. Standard hot-wire techniques were used to study the velocity fluctuations. The Reynolds number range of periodic vortex shedding is divided into two distinct subranges" (p. 1).

From Introduction: "The intermediate subsonic speed range is considered and the liquid-metal turbine-propeller cycle discussed in this report. In this report, compressor pressure ratio, heat-exchanger air-inlet Mach number, and turbine-inlet temperature were optimized for maximum engine net thrust per engine-plus-heat exchanger weight (minimum airplane gross weight) for a range of heat-exchanger effective wall temperature."

From Introduction: "The intermediate subsonic speed range is considered and the liquid-metal turbine-propeller cycle discussed in this report. In this report, compressor pressure ratio, heat-exchanger air-inlet Mach number, and turbine-inlet temperature were optimized for maximum engine net thrust per engine-plus-heat-exchanger weight (minimum airplane gross weight) for a range of heat-exchanger effective wall temperature."

Report presents the results of an investigation conducted to determine the effectiveness of liquid-cooling films on the inner surfaces of tubes containing flowing hot air. Experiments were made in 2- and 4-inch-diameter straight metal tubes with air flows at temperatures from 600 degrees to 2000 degrees F. and diameter Reynolds numbers from 2.2 to 14 x 10(5). The film coolant, water, was injected around the circumference at a single axial position on the tubes at flow rates from 0.02 to .24 pound per second per foot of tube circumference (0.8 to 12 percent of the air flow). Liquid-coolant films were established and maintained around and along the tube wall in concurrent flow with the hot air. The results indicated that, in order to film cool a given surface area with as little coolant flow as possible, it may be necessary to limit the flow of coolant introduced at a single axial position and to introduce it at several axial positions. The flow rate of inert coolant required to maintain liquid-film cooling over a given area of tube surface can be estimated when the gas-flow conditions are known by means of a generalized plot of the film-cooling data.

Report presenting preliminary results of one phase of a control-motion study program using data obtained from 276 maneuvers performed using a McDonnell F2H-2 jet fighter airplane during normal squadron operational training. Results regarding classification of maneuvers, airspeed, load factors, sideslip angle, and maximum pitching-, rolling-, and yawing-angular-acceleration variations with indicated airspeed are provided.

Report presenting a low-speed investigation in the stability tunnel to determine the effects of tail height, length, and aspect ratio on the static longitudinal stability and control characteristics of a 60 degree triangular-wing model with twin triangular all-movable tails located near the wing tips.

"Preliminary results of one phase of a control-motion study program are presented in the form of plots of load factor.and angular acceleration against indicated airspeed and of time histories of several measured quantities. The results were obtained from 197 maneuvers performed by an F-86A jet-fighter airplane during normal squadron operational training. Most of the tactical maneuvers of which the F-86A is capable were performed at pressure altitudes ranging from 0 to 32,000 feet and at indicated airspeeds ranging from 95 to 650 miles per hour" (p. 1).

Memorandum presenting an investigation of a 2:1 area ratio conical diffuser of length equal to the inlet diameter with separate variation of several basic parameters for simple nontwisted counterrotating rectangular vortex generators over a considerable range of inlet-boundary-layer thickness. The maximum values of static-pressure rise were determined for angle of attack, spacing, aspect ratio, and span-to-inlet boundary-layer thickness. Results for the diffuser with no vortex generators, effects of selectable vortex-generator variables, effect of inlet-boundary-layer displacement thickness, and use of the maximum indicated vortex-generator design values are provided.

Memorandum presenting flutter tests of untapered, low-aspect-ratio, sweptback-wing models and of triangular-wing models of solid magnesium, aluminum, and steel construction in an intermittent supersonic wind tunnel at Mach number 1.3. Flutter data are presented for 31 sweptback wing models and 24 triangular-wing models. The flutter boundaries are indicated on plots of streamwise thickness ratio and aspect ratio.

"A pneumatic probe based on continuity of mass flow through two restrictions separated by a cooling chamber was constructed to measure gas temperature at and beyond the limit of thermocouples. This probe consisted of a subsonic flat-plate orifice for the first restriction and a sonic-flow converging-diverging nozzle for the second restriction. The effect of variation in gas constants on the calibration is examined for common engine-exhaust gases" (p. 1).

Report presenting an investigation at Mach number 1.6 and a range of Reynolds number of the skin-friction drag and boundary-layer transition of a body of revolution. The body had a parabolic-arc profile, a blunt base, and a fineness ratio of 12.2 (NACA RM-10). Results regarding the effect of surface condition, drag breakdown, and results of boundary-layer surveys are provided.

Report presenting an investigation of the aerodynamic loading characteristics of a wing-fuselage combination in the slotted test section of the transonic tunnel. The test was part of a systematic investigation of the effects of varying the amount of sweepback on wings in order to determine their suitability for transonic flight. Results regarding span load characteristics, normal-force characteristics, wing-tip angle of twist, spanwise distribution of section pitching-moment coefficient, pitching-moment characteristics, and fuselage characteristics in presence of wing are provided.

Memorandum presenting results obtained from time-history records of normal accelerations, airspeed, and altitude. Additional data have been obtained from the operations of two types of commercial transport airplanes together with data on two other types of transport airplanes.

Report presenting the application of an aerodynamically pulsed horizontal tail to determine experimentally the longitudinal aerodynamic characteristics of a rocket-powered model in free flight. Results regarding time history, lift and drag, and tail effectiveness and downwash are provided.

An analysis of the longitudinal characteristics of swept wings which is based on available large-scale low-speed data and supplemented with low-scale data when feasible is presented. The emphasis has been placed on the differentiation of the characteristics by a differentiation between the basic flow phenomenon involved. Insofar as possible all large-scale data available as of August 15, 1951 have been summarized in tabular form for ready reference.

From Summary: "Tests and calibrations of an AWS instrument shelter were made in the Langley 300 MPH 7- by 10-foot tunnel for the Signal Corps, U.S. Army. The behavior of the wind vane, the 3-cup anemometer, and the shelter cover was determined in wind speeds up to 150 miles per hour. It was discovered that the rotational speed of the anenometer was greatly influenced by the location, with respect to the wind direction, of three spacer posts that held two upper bays of instruments above the anenometer."

Report presenting an experimental investigation to determine the aerodynamic load distributions of a series of five bodies with conical or slightly blunted noses and cylindrical afterbodies in the 1- by 1-foot supersonic wind tunnel. Pressure distributions and viscous drags were measured at Mach number 3.12 for a range of Reynolds numbers and angles of attack.

Report presenting an experimental two-dimensional investigation of the mechanism of the flow and losses involved in the operation of a low-solidity highly loaded turbine-blade profile suitable for use in an air-cooled turbine, which has been made in a cascade.

This paper presents the results of an induced angle-of-attack calculation using a method applicable to a propeller with arbitrary circulation distribution. Tables of induced angles of attack and section angles of attack and curves of wake-survey results are presented for the NACA 10-(3)(066)-03, 10-(3)(049)-03, 10-(3)(090)-03, 10-(5)(066)-03, and 10-(0)(066)-03 propellers. A brief description of the method of calculating propeller induced angles of attack is given.

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.

From Introduction: "The results of this complete evaluation of the altitude performance and operational characteristics of the two types of flame-holder and fuel-system configurations are reported herein.The starting limits of both configurations at a flight Mach number of 0.6 are also discussed."

"An investigation was conducted in the Ames 12-foot pressure wind tunnel to determine the effect of an operating propeller on the aerodynamic characteristics of a 1/19-scale model of the Lockheed XFV-1 airplane. Several full-scale power conditions were simulated at Mach numbers from 0.50 to 0.92; the.Reynolds number was constant at 1.7 million. Lift, longitudinal force, pitch, roll, and yaw characteristics, determined with and without power, are presented for the complete model and for various combinations of model components" (p. 1).

Note presenting a description of basic electrical networks that compensate for the thermal time lag of thermocouple and resistance thermometer elements used in combustion research and in the control of jet power plants. The measurement or the detection of rapid temperature changes by use of such elements can thereby be improved.

An investigation to determine the heat-shock resistant properties of two molybdenum disilicide turbine blades under centrifugal loads imposed by turbine rotation is presented. Molybdenum disilicide turbine blades fabricated by hot-pressing techniques withstood heat-shock conditions under blade centrifugal stresses up to 5350 pounds per square inch. Additional development is required before the heat-shock resistant properties of molybdenum disilicide are satisfactory for turbine-blade application.