National Advisory Committee for Aeronautics (NACA) - 33 Matching Results

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Effect of Normal Pressure on the Critical Compressive Stress of Curved Sheet

Description: Results are presented of tests of two specimens tested to study the effect of normal pressure on the critical compressive stress for thin curved sheets. These specimens are designated by their respective rib spacings of 10 inches and 30 inches. The relationship between compressive stress and normal pressure at which buckles disappeared is independent of whether the buckles were made to disappear by increase of normal pressure or decrease of compressive stress. (author).
Date: August 25, 1942
Creator: Rafel, Norman
Partner: UNT Libraries Government Documents Department

Intercooler cooling-air weight flow and pressure drop for minimum drag loss

Description: An analysis has been made of the drag losses in airplane flight of cross-flow plate and tubular intercoolers to determine the cooling-air weight flow and pressure drop that give a minimum drag loss for any given cooling effectiveness and, thus, a maximum power-plant net gain due to charge-air cooling. The drag losses considered in this analysis are those due to (1) the extra drag imposed on the airplane by the weight of the intercooler, its duct, and its supports and (2) the drag sustained by the cooling air in flowing through the intercooler and its duct. The investigation covers a range of conditions of altitude, airspeed, lift-drag ratio, supercharger-pressure ratio, and supercharger adiabatic efficiency. The optimum values of cooling air pressure drop and weight flow ratio are tabulated. Curves are presented to illustrate the results of the analysis.
Date: February 25, 1944
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

Flight measurements of horizontal tail loads on a typical propeller-driven pursuit airplane during stalled pull-outs at high speed

Description: Report presenting flight measurements of the pressures on the horizontal tail surfaces of a typical propeller-driven pursuit airplane during stalled pull-outs at high Mach number. Unit loads measured on the stabilizer at safe maneuvering limits were not only considerably in excess of the design unit loads, but also occurred in a direction opposite to the design loads. Revision of the tail-load design requirements and manner of specifying safe maneuverability limits to pilots appears necessary.
Date: April 25, 1944
Creator: Clousing, Lawrence A. & Turner, William N.
Partner: UNT Libraries Government Documents Department

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

Description: From Summary: "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."
Date: October 25, 1946
Creator: Sawyer, Richard H.
Partner: UNT Libraries Government Documents Department

Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8 and 19XB-1 Jet- Propulsion Engines: 4 - Analysis of Compressor Performance

Description: Investigations were conducted in the Cleveland altitude wind tunnel to determine the performance and operational characteristics of the 19B-2, 19B-8, and 19XS-1 turbojet engines. One objective was to determine the effect of altitude, flight Mach number, and tail-pipe-nozzle area on the performance characteristics of the six-stage and ten-stage axial-flow compressors of the 19B-8 and 19XB-1 engines, respectively, The data were obtained over a range of simulated altitudes and flight Mach numbers. At each simulated flight condition the engine was run over its full operable range of speeds. Performance characteristics of the 19B-8 and 19XB-1 compressors for the range of operation obtainable in the turboJet-engine installation are presented. Compressor characteristics are presented as functions of air flow corrected to sea-level conditions, compressor Mach number, and compressor load coefficient. For the range of compressor operation investigated, changes in Reynolds number had no measurable effect on the relations among compressor Mach number, corrected air flow, compressor load coefficient, compressor pressure ratio, and compressor efficiency. The operating lines for the 19B-8 compressor lay on the low-air-flow side of the region of maximum compressor efficiency; the 19B-8 compressor operated at higher average pressure coefficients per stage and produced a lower over-all pressure ratio than did the 19XB-1 compressor.
Date: April 25, 1947
Creator: Dietz, Robert O. & Kuenzig, John K.
Partner: UNT Libraries Government Documents Department

Effects of compressibility on the characteristics of five airfoils

Description: Report presenting the results of pressure-distribution tests to determine the effects of compressibility on the characteristics of the NACA 66,2-215, 66,2-015, 65(216)-418, 16-212, and 23015 airfoil sections. Schileren photographs of the air flow and data on the wake characteristics was also obtained.
Date: April 25, 1947
Creator: Daley, Bernard N.
Partner: UNT Libraries Government Documents Department

Flight observations of aileron flutter at high Mach numbers as affected by several modifications

Description: Report presenting an investigation of aileron flutter associated with high-speed flight. When the aileron control system was modified by installing a hydraulic irreversible unit, it was possible to delay aileron flutter and reduce its amplitude. Results regarding the aileron flutter with and without the modifications, analysis of the time histories for the control systems, and relation between aileron upfloat and flutter are provided.
Date: April 25, 1947
Creator: Spreiter, John R.; Galster, George M. & Cooper, George E.
Partner: UNT Libraries Government Documents Department

Flight-Test Evaluation of the Longitudinal Stability and Control Characteristics of 0.5-Scale Models of the Fairchild Lark Pilotless-Aircraft Configuration: Standard Configuration with Wing Flaps Deflected 60 Degrees and Model having Tail in Line with Wings, TED No. NACA 2387

Description: Flight tests were conducted at the Flight Test Station of the Pilotless Aircraft Research Division at Wallop Island, Va., to determine the longitudinal control and stability characteristics of 0.5-scale models of the Fairchild Lark pilotless aircraft with the tail in line with the wings a d with the horizontal wing flaps deflected 60 deg. The data were obtained by the use of a telemeter and by radar tracking.
Date: June 25, 1947
Creator: Stone, David G.
Partner: UNT Libraries Government Documents Department

Performance of a 20-inch steady-flow ram jet at high altitudes and ram-pressure ratios

Description: Report presenting the results of an investigation conducted in the altitude wind tunnel to determine the performance of a 20-inch ramjet. The investigation was conducted at a range of altitudes and ram-pressure ratios using preheated 62-octane fuel. A net thrust of 8135 pounds educed to standard sea-level conditions, a net-thrust coefficient of 0.74, and an overall efficiency of 12.6 percent were attained at Mach number 1.845 at which the engine with a 5-foot combustion chamber was operated.
Date: June 25, 1947
Creator: Perchonok, Eugene; Sterbentz, William H. & Wilcox, Fred A.
Partner: UNT Libraries Government Documents Department

Pressure-distribution measurements on a full-scale horizontal tail surface for a Mach number range of 0.20 to 0.70

Description: Report presenting testing of a full-scale, semispan, horizontal tail surface for a jet-propelled fighter airplane in the 16-foot high-speed tunnel to determine the variation of the chordwise and spanwise pressure distributions with Mach number. Surface irregularities were found to cause appreciable distortion of the pressure distribution. Results regarding chordwise distributions, spanwise distribution, effect of Mach number on root bending moment, and estimated critical Mach numbers are provided.
Date: June 25, 1947
Creator: Schueller, Carl F.
Partner: UNT Libraries Government Documents Department

The use of perforated inlets for efficient supersonic diffusion

Description: Report presenting the use of wall perforations on supersonic diffusers to avoid the internal contraction-ratio limitation. Experimental results on a preliminary model of a perforated diffuser at Mach number 1.85 are provided. A theoretical discussion of the flow coefficients and the size and spacing of the perforations are included.
Date: June 25, 1947
Creator: Evvard, John C. & Blakey, John W.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of bomb-bay configurations intended to minimize the tumbling of light-weight bombs

Description: Report presenting an investigation in the 300 mph 7- by 10-foot tunnel to determine what modifications could be made to conventional bomb bays to reduce the tumbling difficulties experienced with light-weight bombs. The investigation indicated that there is a definite region of reversed flow inside the bomb bay which must be weakened or destroyed if good drops are to be obtained.
Date: June 25, 1947
Creator: Kuhn, Richard E. & Polhamus, Edward C.
Partner: UNT Libraries Government Documents Department

Determination of Stress-Rupture Parameters for Four Heat-Resisting Alloys

Description: Stress-rupture data for four heat-resisting alloys are analyzed according to equations of the theory of rate processes. A method for determining the four parameters of structure and composition is demonstrated and the four parameters are determined for each of the alloys: forged S816, cast S816, cast S590, and cast Vitallium. It is concluded that parameters can be determined for an alloy provided sufficient reliable experimental data are available.
Date: August 25, 1947
Creator: Lidman, William G.
Partner: UNT Libraries Government Documents Department

Investigation of Thrust Augmentation of a 1600-Pound Thrust Centrifugal-Flow-Type Turbojet Engine by Injection of Refrigerants at Compressor Inlets

Description: Investigations were conducted to determine effectiveness of refrigerants in increasing thrust of turbojet engines. Mixtures of water an alcohol were injected for a range of total flows up to 2.2 lb/sec. Kerosene was injected into inlets covering a range of injected flows up to approximately 30% of normal engine fuel flow. Injection of 2.0 lb/sec of water alone produced an increase in thrust of 35.8% of rate engine conditions and kerosene produced a negligible increase in thrust. Carbon dioxide increased thrust 23.5 percent.
Date: August 25, 1947
Creator: Jones, William L. & Dowman, Harry W.
Partner: UNT Libraries Government Documents Department

Acceleration Measurements During Landings of a 1/5.5-Size Dynamic Model of the Columbia XJL-1 Amphibian in Smooth Water and in Waves: Langley Tank Model 208M, TED No. NACA 2336

Description: A 1/5.5-size powered dynamic model of the Columbia XJL-1 amphibian was landed in Langley tank no. 1 in smooth water and in oncoming waves of heights from 2.1 feet to 6.4 feet (full-size) and lengths from 50 feet to 264 feet (full-size). The motions and the vertical accelerations of the model were continuously recorded. The greatest vertical acceleration measured during the smooth-water landings was 3.1g.
Date: September 25, 1947
Creator: Clement, Eugene P. & Havens, Robert F.
Partner: UNT Libraries Government Documents Department

An analysis of longitudinal-control problems encountered in flight at transonic speeds with a jet-propelled airplane

Description: From Introduction: "This report presents an analysis based on flight and wind-tunnel test data directed toward the determination of the probable cause of the pitch-up. Wing pressure distribution and stability and control characteristics in the dive are also included."
Date: September 25, 1947
Creator: Brown, Harvey H.; Rolls, L. Stewart & Clousing, Lawrence A.
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

Preliminary investigation at a Mach number of 1.9 and a Reynolds number of 2,200,000 of three ailerons applicable to the Bell XS-2 airplane design

Description: Report presenting testing of a 42.7 degree sweptback tapered wing with three types of ailerons tested at a Mach number of 1.9 and a Reynolds number of 2,200,000; the wing geometry was similar to that of an XS-2 airplane. The purpose of the investigation was to determine the effectiveness of ailerons at these specified flight characteristics. Results regarding the aerodynamic characteristics of the wing are also provided.
Date: May 25, 1948
Creator: Sivells, James C. & Conner, D. William
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the low-speed stability and control characteristics of a model with a sweptback vee tail and a sweptback wing

Description: Report presenting testing in the 300 mph tunnel of a model with a sweptback vee tail and a sweptback wing to determine its low-speed stability and control characteristics. The results are compared to testing with the same tail panel with zero dihedral on the same wing-fuselage combination. The longitudinal stability characteristics, downwash at the tail, longitudinal control characteristics, lateral stability characteristics, and rudder control characteristics are provided.
Date: May 25, 1948
Creator: Polhamus, Edward C.
Partner: UNT Libraries Government Documents Department

Preliminary free-flight investigation of the effect of airfoil section on aileron rolling effectiveness at transonic and supersonic speeds

Description: From Summary: "Results have been obtained by means of a free-flight technique utilizing rocket propulsion which indicate that aileron-rolling-effectiveness characteristics are affected adversely by variations in airfoil section which procedure large increases in the trailing-edge angle."
Date: June 25, 1948
Creator: Sandahl, Carl A.
Partner: UNT Libraries Government Documents Department

Performance of J33-A-23 Turbojet-Engine Compressor, II, Over-All Performance Characteristics of Compressor with 34-Blade Impeller at Equivalent Impeller Speeds from 6000 to 11,750 RPM

Description: "The J33-A-23 compressor with a 34-blade impeller was operated at ambient inlet temperature and an inlet pressure of 14 inches mercury absolute over a range of equivalent impeller speeds from 6000 to 11,750 rpm. Additional runs at equivalent speeds of 7,000, 10,000, and 11,750 rpm and ambient inlet temperature were made at inlet pressures of 5 and 10 inches mercury absolute. The results of this investigation are compared with those of the J33-A-23 compressor with a 17-blade impeller" (p. 1).
Date: August 25, 1948
Creator: Beede, William L. & Kovach, Karl
Partner: UNT Libraries Government Documents Department

Free-flight investigation at transonic and supersonic speeds of the rolling effectiveness of a 42.7 degree sweptback wing having partial-span ailerons

Description: An investigation of the rolling effectiveness at transonic and supersonic speeds of partial-span ailerons on a 42.7 degree sweptback wing having symmetrical circular-arc airfoil sections of 10-percent thickness ratio normal to the wing quarter-chord line has been made by means of rocket-propelled test vehicles. The results are compared with results of a supersonic wind-tunnel test at Mach number 1.9.
Date: October 25, 1948
Creator: Sandahl, Carl A.
Partner: UNT Libraries Government Documents Department

NACA Transonic Wing-Tunnel Test Sections

Description: Memorandum presenting an approximate subsonic theory developed for the solid blockage interference in circular wind tunnels with walls slotted in the direction of flow. The theory indicated the possibility of obtaining zero blockage interference. Tests in a circular slotted tunnel based on the theory confirmed the theoretical predictions.
Date: October 25, 1948
Creator: Wright, Ray H. & Ward, Vernon G.
Partner: UNT Libraries Government Documents Department