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 Decade: 1940-1949
 Year: 1947
 Collection: National Advisory Committee for Aeronautics Collection
Analysis of jet-propulsion-engine combustion-chamber pressure losses

Analysis of jet-propulsion-engine combustion-chamber pressure losses

Date: January 1, 1947
Creator: Pinkel, I Irving & Shames, Harold
Description: The development and the use of a chart for estimating the pressure losses in jet-engine combustion chambers are described. By means of the chart, the pressure losses due to fluid friction and to momentum changes in the air flow accompanying combustion can be separately evaluated. The pressure-loss chart is based on the assumption that the pressure losses in the actual combustion chamber can be matched by those of an equivalent combustion chamber of constant cross-sectional area. The concept of the equivalent combustion chamber serves as a convenient basis for comparing the pressure-loss characteristics of combustion chambers of a variety of designs. The over-all pressure losses computed from the pressure-loss chart are within 7 percent of the experimental values for the three types of combustion chambers considered herein.
Contributing Partner: UNT Libraries Government Documents Department
Analysis of performance of jet engine from characteristics of components I : aerodynamic and matching characteristics of turbine component determined with cold air

Analysis of performance of jet engine from characteristics of components I : aerodynamic and matching characteristics of turbine component determined with cold air

Date: January 1, 1947
Creator: Goldstein, Arthur W
Description: The performance of the turbine component of an NACA research jet engine was investigated with cold air. The interaction and the matching of the turbine with the NACA eight-stage compressor were computed with the combination considered as a jet engine. The over-all performance of the engine was then determined. The internal aerodynamics were studied to the extent of investigating the performance of the first stator ring and its influence on the turbine performance. For this ring, the stream-filament method for computing velocity distribution permitted efficient sections to be designed, but the design condition of free-vortex flow with uniform axial velocities was not obtained.
Contributing Partner: UNT Libraries Government Documents Department
An analysis of the compressive strength of honeycomb cores for sandwich construction

An analysis of the compressive strength of honeycomb cores for sandwich construction

Date: January 1, 1947
Creator: Norris, Charles B
Description: None
Contributing Partner: UNT Libraries Government Documents Department
An analysis of the full-floating journal bearing

An analysis of the full-floating journal bearing

Date: January 1, 1947
Creator: Shaw, M C & Nussdorfer, T J , Jr
Description: An analysis of the operating characteristics of a full-floating journal 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 are reported to verify some results of the analysis.
Contributing Partner: UNT Libraries Government Documents Department
An Anaylsis of Control Requirements and Control Parameters for Direct-Coupled Turbojet Engines

An Anaylsis of Control Requirements and Control Parameters for Direct-Coupled Turbojet Engines

Date: January 1, 1947
Creator: Novik, David & Otto, Edward W.
Description: 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.
Contributing Partner: UNT Libraries Government Documents Department
Application of the analogy between water flow with a free surface and two-dimensional compressible gas flow

Application of the analogy between water flow with a free surface and two-dimensional compressible gas flow

Date: January 1, 1947
Creator: Orlin, W James; Lindner, Norman J & Butterly, Jack G
Description: The theory of the hydraulic analogy -- that is, the analogy between water flow with a free surface and two-dimensional compressible gas flow -- and the limitations and conditions of the analogy are discussed. A test was run using the hydraulic analogy as applied to the flow about circular cylinders of various diameters at subsonic velocities extending into the supercritical range. The apparatus and techniques used in this application are described and criticized. Reasonably satisfactory agreement of pressure distributions and flow fields existed between water and air flow about corresponding bodies. This agreement indicated the possibility of extending experimental compressibility research by new methods.
Contributing Partner: UNT Libraries Government Documents Department
Charts for determining the characteristics of sharp-nose airfoils in two-dimensional flow at supersonic speeds

Charts for determining the characteristics of sharp-nose airfoils in two-dimensional flow at supersonic speeds

Date: January 1, 1947
Creator: Ivey, H Reese; Stickle, George W & Schuettler, Alberta
Description: Solutions of the Hugoniot shock equations and Meyer expansion equations are plotted in such a manner as to permit the pressure distribution, the local Mach number, and the angles of shock waves on arbitrary sharp-nose airfoils at supersonic speeds to be obtained directly. (author).
Contributing Partner: UNT Libraries Government Documents Department
Column and plate compressive strengths of aircraft structural martials extruded 0-1HTA magnesium alloy

Column and plate compressive strengths of aircraft structural martials extruded 0-1HTA magnesium alloy

Date: January 1, 1947
Creator: Heimerl, George J & Niles, Donald E
Description: Column and plate compressive strengths of extruded 0-1HTA magnesium alloy were determined both within and beyond the elastic range from tests of flat end H-section columns and from local instability tests of H-, Z-, and channel section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures.
Contributing Partner: UNT Libraries Government Documents Department
Compressible Flow Tables for Air

Compressible Flow Tables for Air

Date: January 1, 1947
Creator: Burcher, Marie A.
Description: This paper contains a tabulation of functions of the Mach number which are frequently used in high-speed aerodynamics. The tables extend from M = 0 to M = 10.0 in increments of 0.01 and are based on the assumption that air is a perfect gas having a specific heat ratio of 1.400.
Contributing Partner: UNT Libraries Government Documents Department
Cooling Characteristics of the V-1650-7 Engine. II - Effect of Coolant Conditions on Cylinder Temperatures and Heat Rejection at Several Engine Powers

Cooling Characteristics of the V-1650-7 Engine. II - Effect of Coolant Conditions on Cylinder Temperatures and Heat Rejection at Several Engine Powers

Date: January 1, 1947
Creator: Povolny, John H.; Bogdan, Louis J. & Chelko, Louis J.
Description: An investigation has been conducted on a V-1650-7 engine to determine the cylinder temperatures and the coolant and oil heat rejections over a range of coolant flows (50 to 200 gal/min) and oil inlet temperatures (160 to 2150 F) for two values of coolant outlet temperature (250 deg and 275 F) at each of four power conditions ranging from approximately 1100 to 2000 brake horsepower. Data were obtained for several values of block-outlet pressure at each of the two coolant outlet temperatures. A mixture of 30 percent by volume of ethylene glycol and 70-percent water was used as the coolant. The effect of varying coolant flow, coolant outlet temperature, and coolant outlet pressure over the ranges investigated on cylinder-head temperatures was small (0 deg to 25 F) whereas the effect of increasing the engine power condition from ll00 to 2000 brake horsepower was large (maximum head-temperature increase, 110 F).
Contributing Partner: UNT Libraries Government Documents Department
Critical stress of thin-walled cylinders in axial compression

Critical stress of thin-walled cylinders in axial compression

Date: January 1, 1947
Creator: Batdorf, S B; Schildcrout, Murry & Stein, Manuel
Description: Empirical design curves are presented for the critical stress of thin-wall cylinders loaded in axial compression. These curves are plotted in terms of the nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75.
Contributing Partner: UNT Libraries Government Documents Department
Critical stress of thin-walled cylinders in axial compression

Critical stress of thin-walled cylinders in axial compression

Date: January 1, 1947
Creator: Batdorf, S B; Shildcrout, Murry & Stein, Manuel
Description: Empirical design curves are presented for the critical stress of thin-walled cylinders loaded in axial compression. These curves are plotted in terms of nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75. The test data obtained from various sources follow the general trend of the theoretical curve for cylinders with clamped edges, agreeing closely with the theory in the case of short cylinders, but falling considerably below the theoretical results for long cylinders. The discrepancy in the case of long cylinders increases with increasing values of the ratio of radius to wall thickness. Plotting curves for different values of this ratio reduces the scatter in the test data and a certain degree of correlation with theory is achieved. Advantage is taken of this correlation to obtain estimated design curves for cylinders with simply supported edges, for which little experimental information is available. (author).
Contributing Partner: UNT Libraries Government Documents Department
Determination of elastic stresses in gas-turbine disks

Determination of elastic stresses in gas-turbine disks

Date: January 1, 1947
Creator: Manson, S S
Description: A method is presented for the calculation of elastic stresses in symmetrical disks typical of those of a high-temperature gas turbine. The method is essentially a finite-difference solution of the equilibrium and compatibility equations for elastic stresses in a symmetrical disk. Account can be taken of point-to-point variations in disk thickness, in temperature, in elastic modulus, in coefficient of thermal expansion, in material density, and in Poisson's ratio. No numerical integration or trial-and-error procedures are involved and the computations can be performed in rapid and routine fashion by nontechnical computers with little engineering supervision. Checks on problems for which exact mathematical solutions are known indicate that the method yields results of high accuracy. Illustrative examples are presented to show the manner of treating solid disks, disks with central holes, and disks constructed either of a single material or two or more welded materials. The effect of shrink fitting is taken into account by a very simple device.
Contributing Partner: UNT Libraries Government Documents Department
Determination of elastic stresses in gas-turbine disks

Determination of elastic stresses in gas-turbine disks

Date: January 1, 1947
Creator: Manson, S S
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Effect of brake forming in various tempers on the strength of Alclad 75S-T aluminum-alloy sheet

Effect of brake forming in various tempers on the strength of Alclad 75S-T aluminum-alloy sheet

Date: January 1, 1947
Creator: Woods, Walter & Heimerl, George J
Description: Results are presented of tests to determine the effect of brake forming in various tempers on the strength of Alclad 75S-T aluminum alloy sheet in the direction parallel to the brake. The tensile and compressive strengths of Alclad 75S-T sheet, formed in the O and W tempers, were either increased or little affected compared with those of similarly treated unformed material. When Alclad 75S-T sheet 'as received' was formed, however, the tensile yield stress was reduced about 7 percent for the with-grain direction and 1 percent for the cross-grain direction, whereas the tensile ultimate and compressive yield stresses were increased somewhat. The elongation was always slightly reduced as a result of forming.
Contributing Partner: UNT Libraries Government Documents Department
Effect of combustor-inlet conditions on performance of an annular turbojet combustor

Effect of combustor-inlet conditions on performance of an annular turbojet combustor

Date: January 1, 1947
Creator: Childs, J Howard; Mccafferty, Richard J & Surine, Oakley W
Description: The combustion performance, and particularly the phenomenon of altitude operational limits, was studied by operating the annular combustor of a turbojet engine over a range of conditions of air flow, inlet pressure, inlet temperature, and fuel flow. Information was obtained on the combustion efficiencies, the effect on combustion of inlet variables, the altitude operational limits with two different fuels, the pressure losses in the combustor, the temperature and velocity profiles at the combustor outlet, the extent of afterburning, the fuel-injection characteristics, and the condition of the combustor basket.
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Effect of rivet or bolt holes on the ultimate strength developed by 24S-T and Alclad 75S-T sheet in incomplete diagonal tension

Effect of rivet or bolt holes on the ultimate strength developed by 24S-T and Alclad 75S-T sheet in incomplete diagonal tension

Date: January 1, 1947
Creator: Levin, L Ross & Nelson, David H
Description: Strength tests were made of a number of 24S-T and Alclad 75S-T aluminum alloy shear webs to determine the effect of rivet or bolt holes on the shear strength. Data were obtained for webs which approached a condition of pure shear stress as well as for webs with well-developed diagonal tension. The rivet factor (pitch minus diameter), divided by pitch, was varied from approximately 0.81 to 0.62. These tests indicated that the shear stresses on the gross section were nearly constant for all values of the rivet factor investigated if the other properties of the web were not changed.
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Effect of Various Methods of Boundary-Layer Control on Performance of V-1710-93 Engine-Stage Supercharger

Effect of Various Methods of Boundary-Layer Control on Performance of V-1710-93 Engine-Stage Supercharger

Date: January 1, 1947
Creator: Kohl, Robert C. & Diggs, Donald R.
Description: Four methods of boundary-layer control were tried during an investigation to improve the flow in the impeller passages of a V-1710-93 engine-stage supercharger. The boundary layer along the impeller front shroud was removed by suction. In one method the removal was accomplished by recirculation of the air to the impeller inlet; in another method, by external removal. In the other methods, slots were cut through the impeller-blade faces first at 30 percent and then at 30 and 70 percent of the mean-flow-path length measured from leading edges of the rotating inlet guide vanes to introduce air from the high-pressure side of the blades into the region where stagnation and separation were suspected. A slight improvement in performance was obtained when the boundary layer was removed through the impeller front shroud. In general, this improvement become more pronounced as the amount of air removed was increased even though the excessive impeller frontal clearance maintained for these tests, together with an exaggerated negative pressure gradient, apparently induced flow separation on the diffuser front and rear walls as well as on the impeller front shroud. The use of slots in the impellers at the locations selected had a detrimental effect on the supercharger ...
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Effects of sweepback on boundary layer and separation

Effects of sweepback on boundary layer and separation

Date: January 1, 1947
Creator: Jones, Robert T
Description: Following a law of stress adopted in the Navier-Stokes equations, the configuration of the viscous flow in planes at right angles to the axis of an infinite cylinder is found to be independent of the axial motion of the cylinder. In the limiting case of a yawed or swept wing of very high aspect ratio, certain boundary-layer and separation phenomena are thus determined independently by the crosswise component of velocity. It follows that the effect of sweepback is to increase the area of stable laminar flow and to decrease the lift coefficient at which flow separation occurs.
Contributing Partner: UNT Libraries Government Documents Department
Effects of temperature distribution and elastic properties of materials on gas-turbine-disk stresses

Effects of temperature distribution and elastic properties of materials on gas-turbine-disk stresses

Date: January 1, 1947
Creator: Holms, Arthur G & Faldetta, Richard D
Description: Calculations were made to determine the influence of changes in temperature distribution and in elastic material properties on calculated elastic stresses for a typical gas-turbine disk. Severe temperature gradients caused thermal stresses of sufficient magnitude to reduce the operating safety of the disk. Small temperature gradients were found to be desirable because they produced thermal stresses that subtracted from the centrifugal stresses in the region of the rim. The thermal gradients produced a tendency for a severe stress condition to exist near the rim but this stress condition could be shifted away from the region of blade attachment by altering the temperature distribution. The investigation of elastic material properties showed that centrifugal stresses are slightly affected by changes in modulus of elasticity, but that thermal stresses are approximately proportional to modulus of elasticity and to coefficient of thermal expansion.
Contributing Partner: UNT Libraries Government Documents Department
Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms: September 5, 1946 to September 10, 1946 at Orlando, Florida

Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms: September 5, 1946 to September 10, 1946 at Orlando, Florida

Date: January 1, 1947
Creator: Tolefson, H. B.
Description: Tables I and II of this report summarize the gust and draft velocity data for thunderstorm flights 31, 32, and 33 of September 5, 1946, September 6, 1946, and September 10, 1946, respectively. These data were evaluated from records of NACA instruments installed in P-61C airplanes and are of the type presented for previous flights. Table III summarizes the readings of a milliammeter which was used in conjunction with other equipment to indicate ambient air temperature during thunderstorm surveys. These data were read from motion-picture records of the instrument and include all cases in which variations in the instrument indications were noted for the present flights.
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Flight investigation on a fighter-type airplane of factors which affect the loads and load distributions on the vertical tail surfaces during rudder kicks and fishtails

Flight investigation on a fighter-type airplane of factors which affect the loads and load distributions on the vertical tail surfaces during rudder kicks and fishtails

Date: January 1, 1947
Creator: Boshar, John
Description: Results are presented of a flight investigation conducted on a fighter-type airplane to determine the factors which affect the loads and load distributions on the vertical tail surfaces in maneuvers. An analysis is made of the data obtained in steady flight, rudder kicks, and fishtail maneuvers. For the rudder kicks, the significant loads were the "deflection load" resulting from an abrupt control deflection and the "dynamic load" consisting of a load corresponding to the new static equilibrium condition for the rudder deflected plus a load due to a transient overshoot. The minimum time to reach the maximum control deflection attainable by the pilot in any flight condition was found to be a constant. In the fishtail maneuvers, it was found that the pilot tends to deflect the rudder in phase with the natural frequency of the airplane. The maximum loads measured in fishtails were of the same order of magnitude as those from a rudder kick in which the rudder is returned to zero at the time of maximum sideslip.
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Flight measurements of the lateral control characteristics of narrow-chord ailerons on the trailing edge of a full-span slotted flap

Flight measurements of the lateral control characteristics of narrow-chord ailerons on the trailing edge of a full-span slotted flap

Date: January 1, 1947
Creator: Sawyer, Richard H
Description: Results are presented of light tests made to determine the effect of flap deflection on the lateral control characteristics of a modified brewster f2a-2 airplane equipped with partial-span narrow-chord ailerons on the trailing edge of a full-span NACA slotted flap. The investigation included determination of the rolling and yawing characteristics of the airplane in abrupt aileron rolls with the slotted flap at various settings ranging from 0 degree to about 40 degrees. The results showed that the effectiveness of the ailerons was greatly reduced at flap deflections greater than about 20 degrees. For flap deflections up to about 20 degrees, the aileron effectiveness was about the same as with flaps retracted, but the adverse yawing velocity developed in the abrupt aileron rolls was somewhat increased.
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Free-Spinning-Tunnel Tests of a 1/27-Scale Model of the Douglas XF3D-1 Airplane, TED No. NACA DE 312

Free-Spinning-Tunnel Tests of a 1/27-Scale Model of the Douglas XF3D-1 Airplane, TED No. NACA DE 312

Date: January 1, 1947
Creator: Scher, Stanley H.
Description: Free-spinning-tunnel tests have been made on a 1/27-scale model of the Douglas XF3D-1 airplane to confirm a preliminary evaluation made of the airplane spin and recovery characteristics and previously reported. Recovery characteristics were satisfactory for erect and inverted spins when the model was in the clean condition. When the slow-down brakes were open, recoveries were slow. The pedal force necessary to reverse the airplane rudder during a spin will be within the physical capabilities of the pilot. A 10-foot-diameter parachute attached to the tail of the airplane (laid-out-flat diameter, drag coefficient 0.7) or a 4.5-foot-diameter parachute attached to the outboard wing tip will be satisfactory for emergency spin recovery from demonstration spins. If it becomes necessary for the crew to abandon the airplane during a spin, they should leave from the outboard side of the cockpit. The test results indicated spin and recovery characteristics generally similar to those indicated in the preliminary evaluation.
Contributing Partner: UNT Libraries Government Documents Department
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