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System Analyses and Autopilot Design for Automatic Roll Stabilization of a Supersonic Pilotless Aircraft

Description: Memorandum presenting system analyses and autopilot design procedure for a supersonic pilotless aircraft with twin jet engines. The autopilots investigated were a gyro-actuated control, a gyro-actuated control with a rate-sensing device, and an electronic-hydraulic autopilot. Results regarding the airframe and gyro-actuated control system; airframe, gyro-actuated control, and rate servo; airframe and electronic-hydraulic autopilot; and contribution of method of analysis to system design are provided.
Date: July 11, 1951
Creator: Zarovsky, Jacob
Partner: UNT Libraries Government Documents Department

Effect of Dissociation on Exhaust-Nozzle Performance

Description: Memorandum presenting net jet thrusts for stoichiometric hydrocarbon-air, hydrogen-air and pentaborane-air mixtures for equilibrium and frozen expansion in the exhaust nozzle at flight Mach numbers up to 10. Examinations of the dissociation products involved and the energies associated with them, for the hydrocarbon- and hydrogen-air mixtures indicated that a major portion of the dissociation energy for the hydrocarbon mixture is involved in the carbon monoxide molecule.
Date: June 11, 1958
Creator: Reynolds, T. W.
Partner: UNT Libraries Government Documents Department

An Investigation of the Low-Speed Stability and Control Characteristics of a 1/10-Scale Model of the McDonnell XF3H-1 Airplane: TED No. NACA DE 344

Description: "At the request of the Bureau of Aeronautics, Navy Department, an investigation of the low-speed, power-off stability and control characteristics of a 1/10-scale model of the McDonnell XF3H-1 airplane has been made in the Langley free-flight tunnel. Flight tests of the model in the clean and in the slats-and-flaps-extended conditions were made over a lift-coefficient range from about 0.5 through the stall. Only low-altitude conditions were simulated and no attempt was made to determine the effect on the stability characteristics of freeing the controls" (p. 1).
Date: October 11, 1951
Creator: Draper, John W.
Partner: UNT Libraries Government Documents Department

Langley Free-Flight-Tunnel Investigation of the Automatic Lateral Stability Characteristics of a Model Equipped with a Gyro Stabilizing Unit that Provided either Flicker-Type or Hunting Control

Description: Memorandum presenting an investigation to determine the automatic lateral stability characteristics of a model equipped with a gyro stabilizing unit that gave response to bank and yaw. Stable flights were obtained with the flicker-type automatic control, and the amplitude of the oscillations was decreased by adding the attachment which provided hunting control.
Date: January 11, 1949
Creator: Schade, Robert O.
Partner: UNT Libraries Government Documents Department

Investigation of Turbojet Engine Performance at Speeds and Gas Temperatures Above Rated Using Turbine-Blade External Water-Spray Cooling from Stationary Injection Orifices

Description: Memorandum presenting a turbojet engine with a centrifugal-flow compressor which permitted overspeed, overtemperature operation and was modified for spray cooling. The effectiveness of spray cooling as a method which permits operation at overspeed, overtemperature conditions with this engine was investigated and the overspeed, overtemperature performance was obtained. Results regarding the cooling system performance, turbine performance, and engine performance are provided.
Date: October 11, 1954
Creator: Freche, John & McKinnon, Roy A.
Partner: UNT Libraries Government Documents Department

Performance of Pure Fuels in Single J33 Combustors 2: Hydrocarbon and Nonhydrocarbon Fuels

Description: Memorandum presenting performance investigations of 13 fuels - five hydrocarbons, four oxygenated hydrocarbons, and four substituted hydrocarbon-type fuels - conducted in a single tubular turbojet combustor in order to determine a possible relation between combustor performance and fuel properties. Combustor temperature rise and combustion efficiency were determined at a variety of air-flow rates, inlet-air total temperatures, and a range of heat-input values.
Date: April 11, 1955
Creator: Smith, Arthur L. & Wear, Jerrold D.
Partner: UNT Libraries Government Documents Department

Tests at Mach Number 1.62 of a Series of Missile Configurations Having Tandem Cruciform Lifting Surfaces

Description: Memorandum presenting an investigation at a Mach number of 1.62 in the 9-inch supersonic tunnel of a series of missile configurations with tandem lifting surfaces of low aspect ratio and of nearly equal span. Some of the variables investigated were interdigitation angle, wing and tail plan form, and longitudinal location of wing with respect to tail. Lift, drag, and pitching-moment data are presented, together with center-of-pressure locations and tail-lift efficiency factors.
Date: January 11, 1952
Creator: Grigsby, Carl E.
Partner: UNT Libraries Government Documents Department

An Investigation at Mach Numbers of 1.62 and 1.93 of the Lift Effectiveness and Integrated Downwash Characteristics of Several In-Line Missile Configurations Having Equal-Span Wings and Tails

Description: Memorandum presenting an investigation made at Mach numbers of 1.62 and 1.93 to determine the lift effectiveness and average downwash characteristics of several in-line missile configurations with rectangular and triangular tail plan forms. Breakdown tests were made for combinations of a body and four wing plan forms and two tail plan forms. Results regarding lift and drag results, pitching-moment results, and integrated downwash effects are provided.
Date: April 11, 1952
Creator: Grigsby, Carl E.
Partner: UNT Libraries Government Documents Department

Langley Full-Scale Tunnel Investigation of a 1/3-Scale Model of the Chance Vought XF5U-1 Airplane

Description: From Summary: "The results of an investigation of a 1/3-scale model of the Chance Vought XF5U-1 airplane in the Langley full-scale tunnel are presented in this report. The maximum lift and stalling characteristics of several model configurations, the longitudinal stability characteristics of the model, and the effectiveness of the control surfaces were determined with the propellers removed. The propulsive characteristics, the effect of propeller operation on the lift, and the static thrust of the model propellers were determined at several propeller-blade angles."
Date: October 11, 1946
Creator: Lange, Roy H.; Cocke, Bennie W., Jr. & Proterra, Anthony J.
Partner: UNT Libraries Government Documents Department

Waters Loads on the XJL-1 Hull as Obtained in Langley Impact Basin, TED No. NACA 2413.3

Description: From Summary: "An investigation was conducted in the Langley impact basin of the water loads on a half scale model of the XJL-1 hull whose forebody has a vee bottom with exaggerated chine flare. The impact loads, moments, and pressures were determined for a range of landing conditions. A normal full-scale landing speed of 86 miles per hour was represented with effective flight paths ranging from 0.6deg to 11.6deg. Landings were made with both fixed trim and free-to-trim mounting of the float over a trim range of -15deg to 12deg into smooth water and into waves having equivalent full-scale length of 120 feet and heights ranging from 1 to 4 feet."
Date: October 11, 1946
Creator: Steiner, Margaret F. & Miller, Robert W.
Partner: UNT Libraries Government Documents Department

An analysis of available data on effects of wing-fuselage-tail and wing-nacelle interference on the distribution of the air load among components of airplanes

Description: From Introduction: "The purpose of the present paper is to summarize the available data on the effects of wing-fuselage-tail and wing-nacelle interference on the distribution of the air load among aircraft components. Some discussion is also given of the effects of center-of-gravity position."
Date: April 11, 1949
Creator: Wollner, Bertram C.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a circular cylinder at Mach number 6.86 and angles of attack up to 90 degrees

Description: From Summary: "Pressure-distribution and force tests of a circular cylinder have been made in the Langley 11-inch hypersonic tunnel at a Mach number of 6.86, a Reynolds number of 129,000 based on diameter, and angles of attack up to 90 degrees. The results are compared with the hypersonic approximation of Grimminger, Williams, and Young and with a simple modification of the Newtonian flow theory. The comparison of experimental results shows that either theory gives adequate general aerodynamic characteristics but that the modified Newtonian theory gives a more accurate prediction of the pressure distribution. The calculated crossflow drag coefficients plotted as a function of crossflow Mach number were found to be in reasonable agreement with similar results obtained from other investigations at lower supersonic Mach numbers. Comparison of the results of this investigation with data obtained at a lower Mach number indicates that the drag coefficient of a cylinder normal to the flow is relatively constant for Mach numbers above about 4."
Date: March 11, 1954
Creator: Penland, Jim A.
Partner: UNT Libraries Government Documents Department

Performance of J33-A-27 Turbojet-Engine Compressor 1: Over-all performance characteristics at equivalent impeller speeds from 6100 to 11,800 rpm

Description: The J33-A-27 compressor was operated at an inlet pressure of 14 inches of mercury absolute and ambient inlet temperature over a range of equivalent impeller speeds from 6100 to 11,800 rpm. At the design equivalent speed of 11,800 rpm, the J33-A-27 compressor had a peak pressure ratio of 4.40 at an equivalent weight flow of 105.7 pounds per second and a peak adiabatic temperature-rise efficiency of 0.745. The maximum equivalent weight flow at design speed was 113.5 pounds per second.
Date: July 11, 1949
Creator: Kovach, Karl & Osborn, Walter M.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of the Static Longitudinal Stability Characteristics of a 0.15-Scale Model of the Hermes A-1E2 Missile at High Subsonic Mach Numbers

Description: The static longitudinal stability characteristics of a 0.15-scale model of the Hermes A-lE2 missile have been determined in the Langley high-speed 7- by 10-foot tunnel over a Mach number range of 0.50 to 0.98, corresponding to Reynolds numbers, based on body length, of 12.3 x 10(exp 6) to 17.1 x 10(exp 6). This paper presents results obtained with body alone and body-fins combinations at 0 degrees (one set of fins vertical and the other set horizontal) and 45 degree angle of roll. The results indicate that the addition of the fins to the body insures static longitudinal stability and provides essentially linear variations of the lift and pitching moment at small angles of attack throughout the Mach number range. The slopes of the lift and pitching-moment curves vary slightly with Mach number and show only small effects due to the angle of roll.
Date: September 11, 1952
Creator: Alford, William J., Jr.
Partner: UNT Libraries Government Documents Department

Component Performance Investigation of J71 Experimental Turbine, Part 2, Internal-Flow Conditions with 97-Percent-Design Stator Areas

Description: An experimental investigation of the internal-flow conditions of a J71 experimental turbine equipped with 97-percent-design stator areas was conducted at equivalent design speed and near equivalent design work. The results of the investigation indicate that the stage work distribution closely approximates design, the actual distribution being 44.1, 33.4, and 22.5 percent for the first, second, and third stages, respectively. The first-, second-, and third-stage efficiencies were 0.894, 0.858, and 0.792, respectively. The first and second stages exhibited loss regions near the hub and tip at the rotor blade outlets. The hub loss region is attributed to stator secondary flows, and a contributing factor to the tip loss region may be the high design diffusion on the rotor blade suction surface near the tip. The loss in the third stage is appreciably greater than that in the first or second stage. The fact that the third rotor is unshrouded and has a nominal tip clearance of 0.120 inch may contribute to the higher loss in the tip region of the third stage.
Date: April 11, 1956
Creator: Rebeske, John J., Jr. & Petrash, Donald A.
Partner: UNT Libraries Government Documents Department

Performance Evaluation of Reduced-Chord Rotor Blading as Applied to J73 Two-Stage Turbine

Description: The multistage turbine from the J73 turbojet engine has previously been investigated with standard and with reduced-chord rotor blading in order to determine the individual performance characteristics of each configuration over a range of over-all pressure ratio and speed. Because both turbine configurations exhibited peak efficiencies of over 90 percent, and because both units had relatively wide efficient operating ranges, it was considered of interest to determine the performance of the first stage of the turbine as a separate component. Accordingly, the standard-bladed multistage turbine was modified by removing the second-stage rotor disk and stator and altering the flow passage so that the first stage of the unit could be operated independently. The modified single-stage turbine was then operated over a range of stage pressure ratio and speed. The single-stage turbine operated at a peak brake internal efficiency of over 90 percent at an over-all stage pressure ratio of 1.4 and at 90 percent of design equivalent speed. Furthermore, the unit operated at high efficiencies over a relatively wide operating range. When the single-stage results were compared with the multistage results at the design operating point, it was found that the first stage produced approximately half the total multistage-turbine work output.
Date: July 11, 1957
Creator: Schurn, Harold J.
Partner: UNT Libraries Government Documents Department

The Design of Variable Mach Number Asymmetric Super-Sonic Nozzles by Two Procedures Employing Inclined and Curved Sonic Lines

Description: Two theoretical procedures are developed for designing asymmetric supersonic nozzles for which the calculated exit flow is nearly uniform over a range of Mach numbers. One procedure is applicable at Mach numbers less than approximately 3. This approach yields, without iteration, a nozzle for which the calculated exit flow is uniform at two Mach numbers and, with proper design, is nearly uniform at Mach numbers between, slightly above, and slightly below these two. The use of an inclined and curved sonic line is an essential feature of this approach, The second procedure requires iteration and is used far designs at Mach numbers exceeding 3. Although it is not a necessary feature, an inclined and curved sonic line is also used in this procedure. In both approaches the flow field dawn stream of the sonic line is determined using the method of characteristics.
Date: April 11, 1951
Creator: Syvertson, Clarence A. & Savin, Raymond C.
Partner: UNT Libraries Government Documents Department

Longitudinal Stability and Control Characteristics at Transonic Speeds of a 1/30-Scale Model of the Republic XF-103 Airplane

Description: The longitudinal stability and control characteristics of a 1/30-scale model of the Republic XF-103 airplane were investigated in the Langley 8-foot transonic tunnel. The effect of speed brakes located at the end of the fuselage was also investigated. The main part of the investigation was made with internal flow in the model, but some data were obtained with no internal flow. The longitudinal stability and control at transonic-speeds appeared satisfactory. The transonic drag rise was small. The speed brakes had no adverse effects on longitudinal stability.
Date: August 11, 1954
Creator: Luoma, Arvo A.
Partner: UNT Libraries Government Documents Department

Aerodynamic Design of Axial-flow Compressors. VI - Experimental Flow in Two-Dimensional Cascades

Description: Available experimental two-dimensional cascade data for conventional compressor blade sections are correlated at a reference incidence angle in the region of minimum loss. Variations of reference incidence angle, total-pressure loss, and deviation angle with cascade geometry, inlet Mach number, and Reynolds number are investigated. From the analysis and the correlations of the available data, rules and relations are evolved for the prediction of blade-profile performance. These relations are developed in simplified forms readily applicable to compressor design procedures.
Date: November 11, 1955
Creator: Lieblein, Seymour
Partner: UNT Libraries Government Documents Department

Calculation of Wing Bending Moments and Tail Loads Resulting from the Jettison of Wing Tips During a Symmetrical Pull-Up

Description: A preliminary analytical investigation was made to determine the feasibility of the basic idea of controlled failure points as safety valves for the primary airplane structure. The present analysis considers the possibilities of the breakable wing tip which, in failing as a weak link, would relieve the bending moments on the wing structure. The analysis was carried out by computing the time histories of the wing and stabilizer angle of attack in a 10g pull-up for an XF8F airplane with tips fixed and comparing the results with those for the same maneuver, that is, elevator motion but with tips jettisoned at 8g. The calculations indicate that the increased stability accompanying the loss of the wing tips reduces the bending moment an additional amount above that which would be expected from the initial loss in lift and the inboard shift in load. The vortex shed when the tips are lost may induce a transient load requiring that the tail be made stronger than otherwise.
Date: December 11, 1947
Creator: Boshar, John
Partner: UNT Libraries Government Documents Department

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

Description: 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 ...
Date: February 11, 1947
Creator: Brown, Byron
Partner: UNT Libraries Government Documents Department

An Investigation of the Icing and Heated-air De-icing Characteristics of the R-2600-13 Induction System

Description: A laboratory investigation was made on a Holley 1685-HB carburetor mounted on an R-2600-13 supercharger assembly to determine the icing characteristics and the heated-air de-icing requirements of this portion of the B-25D airplane induction system. Icing has been found to be most prevalent at relatively small throttle openings and, consequently, all runs were made at simulated 60-percent normal rated power condition. Icing characteristics were determined during a series of 15-minute runs over a range of inlet-air conditions. For the de-icing investigation severe impact ice was allowed to form in the induction system and the time required for the recovery of 95 percent of the maximum possible air flow at the original throttle setting was then determined for a range of wet-bulb temperatures. Results of these runs showed that ice on the walls of the carburetor adapter and on the rim of the impeller-shroud portion of the supercharger diffuser plate did not affect engine operation at 60-percent normal rated power. Ice that adversely affected the air flow and the fuel-air ratio was formed only on the central web of the carburetor and then only when the inlet air was saturated or contained free moisture in excess of saturation. No serious ice formations were observed at inlet-air temperatures above 66 0 F or with an inlet-air enthalpy greater than 34 Btu per pound. The maximum temperature at. which any trace of icing could be detected was 1110 F with a relative humidity of approximately 28 percent, The air-flow recovery time for emergency de-icing was 0.3 minute for.an enthalpy of 35 Btu per pound or wet-bulb temperature of 68 0 F. Further increase in enthalpy and wet-bulb temperature above these values resulted in very slight improvement in recovery time. The fuel-air ratio restored by a 5-Minute application of heated air was approximately 7 ...
Date: November 11, 1946
Creator: Chapman, Gilbert E.
Partner: UNT Libraries Government Documents Department

Computed Temperature Distribution and Cooling of Solid Gas-Turbine Blades

Description: Computations were made to determine the temperature distribution and cooling of solid gas-turbine blades.A range of temperatures was used from 1500 degrees to 2500 degrees F, blade-root temperatures from 100 degrees to 1000 degrees F, blade thermal conductivity from 8 to 220 BTU/(hr)(sq ft)(degrees F/ft), and net gas to metal heat transfer coefficients from 75 to 250 BTU/(hr)(sq ft)(degrees F).
Date: February 11, 1947
Creator: Reuter, J. George & Gazley, Carl, Jr.
Partner: UNT Libraries Government Documents Department

Results of Flight Test of an Automatically Stabilized Model C (Swept Back) Four-Wing Tiamat

Description: The results of the first flight test of a swept-back four-wing version of Tiamat (MX-570 model C) which was launched at the NACA Pilotless Aircraft Research Station at W4110PB Island, Va. are presented. In general, the flight behavior was close to that predicted by calculations based an stability theory and oscillating table tests of the autopilot. The flight test thus indicates that the techniques employed to predict automatic stability are valid and practical from an operational viewpoint. The limitations of the method used to predict flight behavior arise from the fact that the calculations assume no coupling among roll, pitch, and yaw, while in actual flight some such coupling does exist.
Date: June 11, 1947
Creator: Seacord, Charles L., Jr. & Teitelbaum, J. M.
Partner: UNT Libraries Government Documents Department