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Wind-tunnel tests of single- and dual-rotating pusher propellers having from three to eight blades

Description: Report presenting tests of 10-foot-diameter, single- and dual-rotating pusher propellers with three to eight blades that were conducted in the 20-foot propeller research tunnel as a continuation of previous investigations of tractor propellers. The propellers were mounted at the rear end of a streamline body in spinners that covered the hubs and part of the shanks. The effects as compared to previous testing differed only in degree of effect size.
Date: February 1942
Creator: Gray, W. H.
Partner: UNT Libraries Government Documents Department

Cooling of Gas Turbines, 2, Effectiveness of Rim Cooling of Blades

Description: An analysis is presented of rim cooling of gas-turbine blades; that is, reducing the temperature at the base of the blade (wheel rim), which cools the blade by conduction alone. Formulas for temperature and stress distributions along the blade are derived and, by the use of experimental stress-rupture data for a typical blade alloy, a relation is established between blade life (time for rupture), operating speed, and amount of rim cooling for several gas temperatures. The effect of blade parameter combining the effects of blade dimensions, blade thermal conductivity, and heat-transfer coefficient is determined. The effect of radiation on the results is approximated. The gas temperatures ranged from 1300F to 1900F and the rim temperature, from 0F to 1000F below the gas temperature. This report is concerned only with blades of uniform cross section, but the conclusions drawn are generally applicable to most modern turbine blades. For a typical rim-cooled blade, gas temperature increases are limited to about 200F for 500F of cooling of the blade base below gas temperature, and additional cooling brings progressively smaller increases. In order to obtain large increases in thermal conductivity or very large decreases in heat-transfer coefficient or blade length or necessary. The increases in gas temperature allowable with rim cooling are particularly small for turbines of large dimensions and high specific mass flows. For a given effective gas temperature, substantial increases in blade life, however, are possible with relatively small amounts of rim cooling.
Date: March 18, 1947
Creator: Wolfenstein, Lincoln; Meyer, Gene L. & McCarthy, John S.
Partner: UNT Libraries Government Documents Department

Investigation of frequency-response characteristics of engine speed for a typical turbine-propeller engine

Description: Experimental frequency-response characteristics of engine speed for a typical turbine-propeller engine are presented. These data were obtained by subjecting the engine to sinusoidal variations of fuel flow and propeller-blade-angle inputs. Correlation is made between these experimental data and analytical frequency-response characteristics obtained from a linear differential equation derived from steady-state torque-speed relations.
Date: March 24, 1950
Creator: Taylor, Burt L., III & Oppenheimer, Frank L.
Partner: UNT Libraries Government Documents Department

The flexible mounting of an airplane engine

Description: Discussed here is the suggested installation of the 'unbalanced' 8-cylinder VE-engine. The suggestion was that a flexible mounting be used instead of bolting the engine rigidly to the airplane structure. It was concluded that a flexible connection between the engine and the airplane is probably possible. A flexible connection primarily diminishes the vibrations due to inertia and, to a lesser degree, those due to torque variation. However, engines vibrate more when freely suspended than when rigidly mounted, and this vibration has a detrimental effect on all connections between the engine and the airplane. Therefore, in view of the relatively insignificant advantages which may be derived from the elastic suspension of the engine, the present rigid mounting is to be preferred. Vibration reduction can be achieved by incorporating in the fuselage as many of the rigid airplane parts as possible.
Date: July 1923
Creator: Kutzbach, K.
Partner: UNT Libraries Government Documents Department

Effects of the spanwise, chordwise and vertical location of an external store on the aerodynamic characteristics of a 60 degree delta wing at Mach numbers of 1.41, 1.62, and 1.96

Description: Report presenting an investigation in the supersonic blowdown tunnel to determine the effects of external store location on the lift, drag, and pitching-moment characteristics of a 60 degree delta wing at Mach numbers of 1.41, 1.62, and 1.96. Brief comparative tests were also made to determine the effect of changing the sweep of the strut attaching the store to the wing and of changing the chordwise location of the swept strut.
Date: October 27, 1952
Creator: Jacobsen, Carl R.
Partner: UNT Libraries Government Documents Department

Control characteristics of trailing-edge spoilers on untapered blunt trailing-edge wings of aspect ratio 2.7 with 0 degree and 45 degrees sweepback at Mach numbers of 1.41 and 1.96

Description: Report presenting an investigation in the supersonic blowdown tunnel to determine the control characteristics of full-span trailing-edge spoilers on two related full-blunt wings with the same aspect ratio but differing angles of sweepback. A similar unswept wing that was larger and had a partially blunt trailing edge was also tested with a full-span trailing-edge spoiler. Results regarding the lift, rolling-moment, and pitching-moment coefficients for unswept wings, the 45-degree sweptback wing, and a comparison of spoiler data with flap data are provided.
Date: December 3, 1952
Creator: Jacobsen, Carl R.
Partner: UNT Libraries Government Documents Department

Preliminary evaluation of the performance of a uniflow two-stroke-cycle spark-ignition engine combined with a blowdown turbine and a steady-flow turbine

Description: Report presenting calculations based on a theoretical analysis for a composite engine consisting of a uniflow two-stroke-cycle spark-ignition engine, a compressor, a blowdown turbine, and a steady-flow turbine. Operation of the engine is considered for four cases of gas mixtures and steady-flow turbine temperatures.
Date: November 25, 1947
Creator: Sather, Bernard I. & Foster, Hampton H.
Partner: UNT Libraries Government Documents Department

An investigation of a supersonic aircraft configuration having a tapered wing with circular-arc sections and 40 degree sweepback: Static longitudinal stability and control characteristics at a Mach number of 1.59

Description: Report presenting an investigation in the 4- by 4-foot supersonic tunnel to determine the static longitudinal stability and control characteristics of a supersonic aircraft configuration at a Mach number of 1.59. The model had a 40 degree sweptback tapered wing with 10-percent-thick circular-arc sections normal to the quarter-chord line.
Date: June 29, 1950
Creator: Spearman, M. Leroy & Hilton, John H., Jr.
Partner: UNT Libraries Government Documents Department

Investigation of a supersonic-compressor rotor with turning to axial direction 1: rotor design and performance

Description: Report presenting an approximate, quasi-three-dimensional design procedure adapted to the design of high solidity, impulse-type supersonic compressors. The method is applied to a compressor rotor with a tip speed of 1600 feet per second in air, an inlet hub-tip radius ratio of 0.75, and an axial discharge relative to the rotor. Results regarding the overall performance, rotor-entrance conditions, static-pressure profiles, discharge conditions, and discharge surveys are provided.
Date: August 19, 1953
Creator: Tysl, Edward R.; Klapproth, John F. & Hartmann, Melvin J.
Partner: UNT Libraries Government Documents Department

An instrument for recording the position of airplane control surfaces

Description: N.A.C.A. has developed an instrument which makes a continuous record of the angular position of the control surfaces of an airplane, not only in steady flight but during acrobatics as well. It has proven useful in researches into stability and controllability, and from records obtained from it many otherwise obscure details of piloting technique have been available for the instruction of pilots, from novices to seasoned experts.
Date: August 1923
Creator: Ronan, K. M.
Partner: UNT Libraries Government Documents Department

Investigation of a full-scale, cascade-type thrust reverser

Description: A double set of turning vanes was carried inside the jet tailpipe. To produce reverse thrust, the tailpipe opens into two side sections and the turning vanes move outward to form a V-shaped cascade, which deflects the exhaust-gas flow. Forward and reverse net thrust were measured over a range of engine speeds with the airplane stationary. Taxi tests were made to determine the comparative stopping distances using wheel braking and reverse thrust separately, and a combination of both. The effect of turning-vane spacing on thrust-reverser performance was determined by scale-model tests using unheated air.
Date: April 1957
Creator: Kohl, Robert C. & Algranti, Joseph S.
Partner: UNT Libraries Government Documents Department

Investigation of ignition characteristics of AN-F-32 and two AN-F-58a fuels in single can-type turbojet combustor

Description: Ignition characteristics of AN-F-32 and two AN-F-58a fuels were studied in a single can-type turbojet combustor under air-flow conditions representing engine speeds of 1600, 2500, and 4000 rpm, altitudes from sea level to 30,000 feet, ambient temperatures at sea level from 90 degrees to minus 36 degrees F, and flight Mach numbers of 0 and 0.6. Critical fuel-flow rates for ignition increased with increase in preignition engine speed, with increase in altitude, or with decrease in sea-level ambient temperature. This flow rate appears to increase in a direct relation to decrease in fuel volatility as indicated by the 10-percent-evaporated temperature.
Date: October 13, 1950
Creator: Rayle, Warren D. & Douglass, Howard W.
Partner: UNT Libraries Government Documents Department

Influence of wing flexibility on force-time relation in shock strut following vertical landing impact

Description: Report presenting testing to determine the force developed in a shock strut as a function of the flexibility of the attached wing structure. Both the experiment and analysis indicated that wing flexibility had some effect on the shape and peak value of the force-time curve in a shock strut.
Date: November 1949
Creator: McPherson, Albert E.; Evans, J., Jr. & Levy, Samuel
Partner: UNT Libraries Government Documents Department

Investigation of two-stage counterrotating compressor 2: first-rotor blade-element performance

Description: Report presenting an analysis of the blade-element performance of a highly loaded transonic rotor with double-circular-arc blades. The rotor was purposely loaded beyond the prudent level for exploratory purposes. Results regarding the radial-distribution plots, blade-element data, element blade-to-blade loss variation, and a comparison of steady-state and hot-wire measurements are provided.
Date: October 5, 1956
Creator: Wright, Linwood C. & Wilcox, Ward W.
Partner: UNT Libraries Government Documents Department

Investigation of two-stage counterrotating compressor I : design and over-all performance of transonic first compressor stage

Description: Report presenting a highly loaded transonic rotor which was designed, built, and tested as part of a two-stage counterrotating-compressor research program. The design conditions were chosen to explore the upper limits of loading and Mach number for the transonic unit. The complete rotor design procedure is presented as well as the recorded stall traces and techniques for obtaining the data.
Date: May 22, 1956
Creator: Wilcox, Ward W. & Wright, Linwood C.
Partner: UNT Libraries Government Documents Department

Investigation of off-design performance of shock-in-rotor type supersonic blading

Description: An analysis of the off-design performance of shock-in rotor-type supersonic blading is presented. The over-all losses are assumed divided into two groups;normal-shock losses, and external-wave losses. Throughout the range of relative entrance Mach numbers from 1.35 to starting, the largest losses can be attributed to the normal shock. An improvement in performance would be expected with a reduction of the normal-shock losses by the introduction of external compression waves.
Date: May 7, 1951
Creator: Graham, Robert C.; Klapproth, John F. & Barina, Frank J.
Partner: UNT Libraries Government Documents Department

Preliminary investigation at transonic speeds of the effect of balancing tabs on the hinge-moment and other aerodynamic characteristics of a full-span flap on a tapered 45 degree sweptback wing of aspect ratio 3

Description: Report presenting an investigation at transonic speeds of the control balancing characteristics of three tabs on a full-span flap on an aspect-ratio-3, 45 degree sweptback wing. The results indicated that all the tabs tested, inset, attached, or detached, would balance the flap hinge moments throughout the speed range.
Date: April 8, 1952
Creator: Lockwood, Vernard E. & Fikes, Joseph E.
Partner: UNT Libraries Government Documents Department

Drag interference between a pointed cylindrical body and triangular wings of various aspect ratios at Mach numbers of 1.50 and 2.02

Description: The drag of a body alone, six triangular wings of various aspect ratios, and the combinations were measured at Mach numbers of 1.50 and 2.02 at a Reynolds number of 5.5 million (based on the body length). The experimental drag-interference results were in accordance with calculations based on NACA RM A9E19, 1949, with skin-friction effects taken into account, the interference effect being principally the result of fixing transition on the body by adding a wing.
Date: November 1956
Creator: Katzen, Elliott D. & Kaattari, George E.
Partner: UNT Libraries Government Documents Department

Drag interference between a pointed cylindrical body and triangular wings of various aspect ratios at Mach numbers of 1.50 and 2.02

Description: The drag of a body alone, six triangular wings of various aspect ratios, and the combinations were measured at Mach numbers of 1.50 and 2.02 at a Reynolds number of 5.5 million (based on the body length). The experimental drag-interference results were in accordance with calculations based on NACA RM A9E19, 1949, with skin-friction effects taken into account, the interference effect being principally the result of fixing transition on the body by adding a wing.
Date: May 23, 1951
Creator: Katzen, Elliott D. & Kaattari, George E.
Partner: UNT Libraries Government Documents Department

Turbine performance characteristics of a python turbine-propeller engine investigated in altitude wind tunnel

Description: Report presenting the performance of the turbine component of a Python turbine-propeller engine with four tail-pipe configurations determined over a range of altitudes, engine speeds, and fuel flows. Results regarding the corrected turbine speed, corrected turbine enthalpy drop, pressure ratio, and efficiency were established on a turbine-characteristic plot.
Date: May 1, 1951
Creator: Farley, John M. & Prince, William R.
Partner: UNT Libraries Government Documents Department

Preliminary investigation of a conical spike inlet in combination with a vertical-wedge auxiliary inlet at Mach number 1.9

Description: Pressure-recovery characteristics of a nacelle-type-spike inlet in combination with a vertical-wedge auxiliary scoop are presented for a free-stream Mach number of 1.9 at zero angle of attack. The auxiliary scoop provided 17 percent additional air flow with a drop in critical pressure recovery from 0.86 to 0.81. However, in terms of inlet-engine matching, the pressure recovery of the undersized spike inlet operating at a specified corrected air flow increased with the scoop open, for example, from 0.69 to 0.81.
Date: September 27, 1955
Creator: Beke, Andrew; Allen, John L. & Williams, Thomas
Partner: UNT Libraries Government Documents Department

Method for calculating the rolling and yawing moments due to rolling for unswept wings with or without flaps or ailerons by use of nonlinear section lift data

Description: From Summary: "The methods of NACA reports 865 and 1090 have been applied to the calculation of the rolling-moment and yawing-moment coefficients due to rolling for unswept wings with or without flaps or ailerons. The methods are based on lifting-line theory and allow the use of nonlinear section lift data. The method presented in this report permits calculations to be made somewhat beyond maximum lift for wings having no twist or continuous twist and employing airfoil sections which do not display large discontinuities in the lift curves. Calculations can be made up to maximum lift for wings with discontinuous twist such as that produced by partial-span flaps or ailerons, or both. Two calculated examples are presented in simplified computing forms in order to illustrate the procedures involved."
Date: January 29, 1953
Creator: Martina, Albert P.
Partner: UNT Libraries Government Documents Department

Investigation of altitude performance of AN-F-58 fuels in annular combustor of J34-WE-22 engine

Description: From Summary: "An investigation was conducted in the combustor of a 3000-pound-thrust turbojet engine to determine the altitude performance characteristics of AN-F-58 fuels. Three fuels conforming to AN-F-58 specification were prepared in order to determine the influence of boiling-temperature range and aromatic content on altitude performance. The performance of the three AN-F-58 fuels was compared with the performance of AN-F-48 (grade 100/130) fuel in the range of simulated altitudes from 20,000 to 55,000 feet, corrected engine speeds from 6000 to 12,500 rpm, and flight Mach numbers of 0.2 and 0.6."
Date: December 5, 1949
Creator: Tischler, Adelbert O. & Scull, Wilfred E.
Partner: UNT Libraries Government Documents Department

Performance characteristics at Mach numbers to 2.0 of various types of side inlets mounted on fuselage of proposed supersonic airplane 1: two-dimensional compression-ramp inlets with semicircular cowls

Description: Report presenting an experimental investigation to determine the performance of twin-scoop side inlets located on the fuselage of a proposed aircraft in a region of large boundary-layer thickness. Inlet configurations with subsonic and supersonic cowlings which utilized two-dimensional compression ramps and ram-type scoops for boundary-layer-removal systems were investigated at several Mach number ranges. Results regarding supersonic Mach number range, angle of attack, subsonic Mach number, and static conditions are provided.
Date: July 16, 1952
Creator: Valerino, Alfred S.
Partner: UNT Libraries Government Documents Department