You limited your search to:

  Partner: UNT Libraries Government Documents Department
 Serial/Series Title: NACA Research Memorandums
 Collection: Technical Report Archive and Image Library
Effect of ice formations on section drag of swept NACA 63A-009 airfoil with partical-span leading-edge slat for various modes of thermal ice protection
Studies were made to determine the effect of ice formations on the section drag of a 6.9-foot-chord 36 degree swept NACA 63A-009 airfoil with partial-span leading-edge slat. In general, the icing of a thin swept airfoil will result in greater aerodynamic penalties than for a thick unswept airfoil. Glaze-ice formations at the leading edge of the airfoil caused large increases in section drag even at liquid-water content of 0.39 gram per cubic meter. The use of an ice-free parting strip in the stagnation region caused a negligible change in drag compared with a completely unheated airfoil. Cyclic de-icing when properly applied caused the drag to decrease almost to the bare-airfoil drag value.
Investigation of turbines for driving supersonic compressors II : performance of first configuration with 2.2 percent reduction in nozzle flow area / Warner L. Stewart, Harold J. Schum, Robert Y. Wong
The experimental performance of a modified turbine for driving a supersonic compressor is presented and compared with the performance of the original configuration to illustrate the effect of small changes in the ratio of nozzle-throat area to rotor-throat area. Performance is based on the performance of turbines designed to operate with both blade rows close to choking. On the basis of the results of this investigation, the ratio of areas is concluded to become especially critical in the design of turbines such as those designed to drive high-speed, high-specific weight-flow compressors where the turbine nozzles and rotor are both very close to choking.
Tabulated pressure coefficients and aerodynamic characteristics measured in flight on the wing of the D-558-I research airplane through a Mach number range of 0.80 to 0.89 and throughout the normal-force-coefficient range at Mach numbers of 0.61, 0.7
No Description
Altitude-chamber performance of British Rolls-Royce Nene II engine III : 18.00-inch-diameter jet nozzle
An altitude-chamber investigation of British Rolls-Royce Nene II turbojet engine was conducted over range of altitudes from sea level to 65,000 feet and ram pressure ratios from 1.10 to 3.50, using an 18.00-inch-diameter jet nozzle. The 18.00-inch-diameter jet nozzle gave slightly lower values of net-thrust specific fuel consumption than either the 18.41- or the standard 18.75-inch-diameter jet nozzles at high flight speeds. At low flight speeds, the 18.41-inch-diameter jet nozzle gave the lowest value of net-thrust specific fuel consumption.
Development of a supersonic area rule and an application to the design of a wing-body combination having high lift-to-drag ratios
No Description
Wing pressure distributions over the lift range of the convair xf-92a delta-wing airplane at subsonic and transonic speeds
No Description
Determination of rate, area, and distribution of impingement of waterdrops on various airfoils from trajectories obtained on the differential analyzer
No Description
Compilation and Analysis of US Turbojet and Ram-Jet Engine Characteristics
No Description
Material compatibility with gaseous fluorine
No Description
An Anaylsis of Control Requirements and Control Parameters for Direct-Coupled Turbojet Engines
Requirements of an automatic engine control, as affected by engine characteristics, have been analyzed for a direct-coupled turbojet engine. Control parameters for various conditions of engine operation are discussed. A hypothetical engine control is presented to illustrate the use of these parameters. An adjustable speed governor was found to offer a desirable method of over-all engine control. The selection of a minimum value of fuel flow was found to offer a means of preventing unstable burner operation during steady-state operation. Until satisfactory high-temperature-measuring devices are developed, air-fuel ratio is considered to be a satisfactory acceleration-control parameter for the attainment of the maximum acceleration rates consistent with safe turbine temperatures. No danger of unstable burner operation exists during acceleration if a temperature-limiting acceleration control is assumed to be effective. Deceleration was found to be accompanied by the possibility of burner blow-out even if a minimum fuel-flow control that prevents burner blow-out during steady-state operation is assumed to be effective. Burner blow-out during deceleration may be eliminated by varying the value of minimum fuel flow as a function of compressor-discharge pressure, but in no case should the fuel flow be allowed to fall below the value required for steady-state burner operation.
An Analysis of the Full-Floating Journal Bearing
An analysis of the operating characteristics of a full-floating bearing - a bearing in which a floating sleeve is located between the journal and bearing surfaces - is presented together with charts - from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing to verify some results of the analysis are reported. The floating sleeve can operate over a wide range of speeds for a given shaft speed, the exact value depending principally upon the ratio of clearances and upon the ratio of radii of the bearing. Lower operating temperatures at high rotative speeds are to be expected by using a full-floating bearing. This lower operating temperature would be obtained at the expense of the load-carrying capacity of the bearing if, for comparison, the clearances remain the same in both bearings. A full-floating bearing having the same load capacity as a conventional journal bearing may be designed if decreased clearances are allowable.
Performance of Compressor of XJ-41-V Turbojet Engine II - Static-Pressure Ratios and Limitation of Maximum Flow at Equivalent Compressor Speed of 8000 rpm
At the request of the Air Material Command, Army Air Forces, an investigation was conducted by the NACA Cleveland laboratory to determine the performance characteristics of the compressor of the XJ-41-V turbojet engine. This report is the second in a series presenting the compressor performance and analysis of flow conditions in the compressor. The static-pressure variation in the direction of flow through the compressor and the location and the cause of the maximum flow restriction at an equivalent speed of 8000 rpm are presented. After the initial runs were reported, the leading edges of the impeller blades and the diffuser surfaces were found to have been roughened by steel particles from a minor failure of auxiliary equipment. The leading edges of the impeller blades were refinished and all high spots resulting from scratches in the diffuser and the accessible parts of the vaned collector passages were removed. The initial overall performance and that obtained with the refinished blades are presented.
Performance of Compressor XJ-41-V Turbojet Engine I - Preliminary Investigation at Equivalent Compressor Speed of 8000 RPM
At the request of the Air Material Command, Arm Air Forces, an investigation was conducted at the NACA Cleveland laboratory to determine the performance characteristics of the XJ-41-V turbojet-engine compressor. The complete compressor was mounted on a collecting chamber having an annular air-flow passage simulating the burner annulus of the engine and was driven by an electric motor. The compressor was extensively instrumented to determine the overall performance of the compressor, the characteristic performance of each of the compressor components, the state of the air stream in the simulated burner annulus, and the operation of the compressor bearings. An initial investigation at an equivalent compressor speed of 8000 rpm was made to determine the performance of the compressor and the collecting chamber and to determine the similarity of the air stream at the entrance to the simulated burner annulus. The mechanical performance of the compressor over a range of actual compressors speeds from 3300 to 8000 rpm is reported.
Design considerations for mixed-flow centrifugal compressors with high weight-flow rates per unit frontal area
An analysis is made of the factors affecting the weight-flow rate per unit frontal area of centrifugal compressors with axial-flow vaned diffusers preceded by mixed-flow vaneless sections. It is shown that, for specified inlet conditions to the impeller and vaned diffuser, the weight-flow rate is increased at the expense of pressure ratio and vice versa. Charts are presented to help the designer make a satisfactory compromise between weight-flow rate and pressure ratio. Some conclusions of the investigation are : (1) Prewhirl is of negligible value in centrifugal compressors designed for high weight-flow rates.
Design considerations of a condensing system for vaporized magnesium
The effect of the design characteristics of various condensing chambers on magnesium build-up at the chamber inlet was investigated. The condensing chambers are used in the vapor-condensation process for making magnesium slurries. A complete description of the various chamber designs and the procedure used in testing the chambers is given. The results are evaluated on the basis of clogging and total magnesium distilled per run. Orifice design was also considered.
Design Data for Graphical Construction of Two-Dimensional Sharp-Edge-Throat Supersonic Nozzles
Design data are presented for the graphical construction of two-dimensional sharp-edge-throat supersonic nozzles of minimum length for test-section Mach numbers from 1.20 to 10.00. The method of characteristics used in the design is briefly reviewed.
The design of brittle-material blade roots based on theory and rupture tests of plastic models
No Description
Design factors for 4- by 8-inch ram-jet combustor
No Description
Calculations of Laminar Heat Transfer Around Cylinders of Arbitrary Cross Section and Transpiration-Cooled Walls with Application to Turbine Blade Cooling
An approximate method for development of flow and thermal boundary layers in laminar regime on cylinders with arbitrary cross section and transpiration-cooled walls is obtained by use of Karman's integrated momentum equation and an analogous heat-flow equation. Incompressible flow with constant property values throughout boundary layer is assumed. Shape parameters for approximated velocity and temperature profiles and functions necessary for solution of boundary-layer equations are presented as charts, reducing calculations to a minimum. The method is applied to determine local heat-transfer coefficients and surface temperature-cooled turbine blades for a given flow rate. Coolant flow distributions necessary for maintaining uniform blade temperatures are also determined.
Carbon deposition of 19 fuels in an annular turbojet combustor
No Description
Cascade investigation of cooling characteristics of a cast-finned air-cooled turbine blade for use in a turboprop engine
No Description
Carbon deposition from AN-F-58 fuels in a J33 single combustor
No Description
Effect of fuel volatility on altitude starting limits of a turbojet engine
The effect of fuel volatility on altitude starting limits of an axial-flow-compressor-type turbojet engine was investigated using fuels with Reid vapor pressures of 1.1 and 5.4 pounds per square inch. At flight Mach numbers from 0.40 to 0.85, the AN-F-58 fuel allowed consistent windmilling at altitudes 2000 to 8000 feet higher than was obtained with the 1.1-pound Reid vapor pressure fuel. At a flight Mach number of 0.25, ignition could not be established at any altitude with the lower-volatility fuel.
Effect of fuel volatility on performance of tail-pipe burner
Fuels having Reid vapor pressures of 6.3 and 1.0 pounds per square inch were investigated in a tail-pipe burner on an axial-flow-type turbojet engine at a simulated flight Mach number of 0.6 and altitudes from 20,000 to 45,000 feet. With the burner configuration used in this investigation, having a mixing length of only 8 inches between the fuel manifold and the flame holder, the low-vapor-pressure fuel gave lower combustion efficiency at a given tail-pipe fuel-air ratio. Because the exhaust-nozzle area was fixed, the lower efficiency resulted in lower thrust and higher specific fuel consumption. The maximum altitude at which the burner would operate was practically unaffected by the change in fuel volatility.
Effect of fuels on combustion efficiency of 5-inch ram-jet-type combustor
No Description
Effect of fuel volatility characteristics on ignition-energy requirements in a turbojet combustor
No Description
Drag data for 16-inch-diameter ram-jet engine with double-cone inlet in free flight at Mach numbers from 0.7 to 1.8
No Description
Downwash in vortex region behind trapezoidal-wing tip at Mach number 1.91
No Description
Drop burning rates of hydrocarbon and nonhydrocarbon fuels
No Description
A drop test for the evaluation of the impact strength of cermets
No Description
Chemical and Physical Properties of Hi-Cal-2
As part of the Navy Project Zip to consider various boron-containing materials as possible high-energy fuels, the chemical and physical properties of Hi-Cal-2 prepared by the Callery Chemical Company were evaluated at the NACA Lewis laboratory. Elemental chemical analysis, heat of combustion, vapor pressure and decomposition, freezing point, density, self ignition temperature, flash point, and blow-out velocity were determined for the fuel. Although the precision of measurement of these properties was not equal to that obtained for hydrocarbons, this special release research memorandum was prepared to make the data available as soon as possible.
Chemical igniters for starting jet fuel - nitric acid rockets
No Description
Chordwise pressures and section moment force and moment coefficients at high subsonic speeds near midspan of a tapered 35 degree sweptback wing with a flap-type control and an attached tab
No Description
Coking of JP-4 fuels in electrically heated metal tubes
A limited exploratory investigation of the rate of coking of four JP-4 fuels in electrically heated metal tubes was conducted in order to provide design information for fuel prevaporizers for turbojet-engine combustors. The fuels tested included two production and two minimum-quality JP-4 type fuels. The heating tube was operated at fuel pressures of approximately 500, 400, and 50 pounds per square inch. The operating fuel temperature was varied between approximately 600 degrees and 1200 degrees F.
Cold-air investigation of a turbine with nontwisted rotor blades suitable for air cooling
No Description
Characteristics of perforated diffusers at free-stream Mach number 1.90
An investigation was conducted at Mach number 1.90 to determine pressure recovery and mass-flow characteristics of series of perforated convergent-divergent supersonic diffusers. Pressure recoveries as high as 96 percent were obtained, but at reduced mass flows through the diffuser. Theoretical considerations of effect of perforation distribution on shock stability in converging section of diffuser are presented and correlated with experimental data. A method of estimating relative importance of pressure recovery and mass flow on internal thrust coefficient basis is given and a comparison of various diffusers investigated is made.
Effect of hot-gas bleedback ice prevention on performance of a turbojet engine with fixed-area tail-pipe nozzle
No Description
Effect of Ice Formations on Section Drag of Swept NACA 63A-009 Airfoil with Partial-Span Leading-Edge Slat for Various Modes of Thermal Ice Protection
The effects of primary and runback ice formations on the section drag of a 36 deg swept NACA 63A-009 airfoil section with a partial-span leading-edge slat were studied over a range of angles of attack from 2 to 8 deg and airspeeds up to 260 miles per hour for icing conditions with liquid-water contents ranging from 0.39 to 1.23 grams per cubic meter and datum air temperatures from 10 to 25 F. The results with slat retracted showed that glaze-ice formations caused large and rapid increases in section drag coefficient and that the rate of change in section drag coefficient for the swept 63A-009 airfoil was about 2-1 times that for an unswept 651-212 airfoil. Removal of the primary ice formations by cyclic de-icing caused the drag to return almost to the bare-airfoil drag value. A comprehensive study of the slat icing and de-icing characteristics was prevented by limitations of the heating system and wake interference caused by the slat tracks and hot-gas supply duct to the slat. In general, the studies showed that icing on a thin swept airfoil will result in more detrimental aerodynamic characteristics than on a thick unswept airfoil.
Effect of ignitor design and ignitor spark-gap environment on ignition in a turbojet combustor
No Description
Effect of immersed surfaces in combustion zone on efficiency and stability of 5-inch diameter ram-jet combustor
No Description
Effect of fuels on screaming in 200-pound-thrust liquid-oxygen - fuel rocket engine
No Description
Effect of fuselage circumferential inlet location on diffuser-discharge total-pressure profiles at supersonic speeds
An experimental investigation of the effect of angle of attack and inlet corrected air flow on diffuser-discharge total-pressure profiles of inlets located in various circumferential positions on a fuselage was conducted at supersonic speeds. Results indicated that the diffuser total-pressure profiles for a bottom inlet were least affected by angle of attack on distortion level was obtained with a side inlet. Variation in distortion for top inlets with angle of attack was confined to the supercritical range of inlet operation.
Effect of geometry on secondary flows in blade rows
No Description
Effect of fuselage fences on the angle-of-attack supersonic performance of a top-inlet - fuselage
No Description
Characteristics of a canard-type missile configuration with an underslung scoop inlet at Mach numbers from 1.5 to 2.0
No Description
Characteristics of a Hot Jet Discharged from a Jet-Propulsion Engine
An investigation of a heated jet was conducted in conjunction with tests of an axial-flow jet-propulsion engine in the Cleveland altitude wind tunnel. Pressure and temperature surveys were made across the jet 10 and 15 feet behind the jet-nozzle outlet of the engine. Surveys were obtained at pressure altitudes of 10,000, 20,000, 30,000, and 40,000 feet with test-section velocities from 30 to 110 feet per second and test-section temperatures from 60 F to -50 F. From measurements taken throughout the operable range of engine speeds, tail-pipe outlet temperatures from 500 F to 1250 F and jet velocities from 400 to 2200 feet per second were obtained. The jet-survey data presented extend the work previously done with low-velocity and low-temperature jets to the region of high velocities and high temperatures. The results obtained agree with previously determined experimental data and with predicted theoretical expressions for the dimensionless transverse velocity and temperature profiles across a jet. The spread of both the temperature and the velocity profiles was very nearly linear. Dimensionless plots of temperature and velocity along the axis of a heated jet agree with experimental results of tests with a cold jet.
Characteristics of a hydraulic control determined from transient data obtained with a turbojet engine at altitude
No Description
Characteristics of a wedge with various holder configurations for static-pressure measurements in subsonic gas streams
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.
Characteristics of flow about axially symmetric isentropic spikes for nose inlets at Mach number 3.85
No Description
Cooling of Gas Turbines I - Effects of Addition of Fins to Blade Tips and Rotor, Admission of Cooling Air Through Part of Nozzles, and Change in Thermal Conductivity of Turbine Components
An analysis was developed for calculating the radial temperature distribution in a gas turbine with only the temperatures of the gas and the cooling air and the surface heat-transfer coefficient known. This analysis was applied to determine the temperatures of a complete wheel of a conventional single-stage impulse exhaust-gas turbine. The temperatures were first calculated for the case of the turbine operating at design conditions of speed, gas flow, etc. and with only the customary cooling arising from exposure of the outer blade flange and one face of the rotor to the air. Calculations were next made for the case of fins applied to the outer blade flange and the rotor. Finally the effects of using part of the nozzles (from 0 to 40 percent) for supplying cooling air and the effects of varying the metal thermal conductivity from 12 to 260 Btu per hour per foot per degree Farenheit on the wheel temperatures were determined. The gas temperatures at the nozzle box used in the calculations ranged from 1600F to 2000F. The results showed that if more than a few hundred degrees of cooling of turbine blades are required other means than indirect cooling with fins on the rotor and outer blade flange would be necessary. The amount of cooling indicated for the type of finning used could produce some improvement in efficiency and a large increase in durability of the wheel. The results also showed that if a large difference is to exist between the effective temperature of the exhaust gas and that of the blade material, as must be the case with present turbine materials and the high exhaust-gas temperatures desired (2000F and above), two alternatives are suggested: (a) If metal with a thermal conductivity comparable with copper is used, then the blade temperature can be reduced by strong cooling at both the blade tip and root. The center of the blade will be less than 2000F hotter than the ends; (b) With low conductivity materials some method of direct cooling other than partial admission of cooling air is essential. From this study, it can be deduced that indirect cooling of turbine blades will not make possible large increases in gas temperature.