UNT Libraries Government Documents Department - 1,158 Matching Results
Search Results
- Free Flight Investigation at Transonic Speeds of the Power-on Characteristics Including Some Effects of Sonic Propulsive Jets of a Four Engine Delta Wing Configuration
- Report discussing a model of a delta-wing configuration with four engines mounted two to a nacelle below the wing that was tested a variety of Mach numbers and Reynolds numbers. The wing static-pressure coefficients, wing pressure coefficients, and lift coefficient of different configurations are described.
- Altitude chamber evaluation of an aircraft liquid hydrogen fuel system used with a turbojet engine
- From Introduction: "The objective of this report are (1) to describe the complete fuel system, (2) to discuss the procedure used for transitions between JP-4 fuel and hydrogen, and (3) to present and discuss engine performance obtained with both fuels, and (4) to review the reliability of the fuel system."
- Design and performance of flight-type liquid-hydrogen heat exchanger
- Report presenting an investigation of a liquid-hydrogen fuel system developed to operate one of the turbojet engines in a twin-engine light bomber at an altitude of 50,000 feet and Mach number 0.75. The heat exchanger was evaluated in an altitude test chamber in conjunction with the complete aircraft fuel system. Results regarding calculated heat-exchanger performance, experimental heat-exchanger performance, and reliability are provided.
- Design and Performance of Fuel Control for Aircraft Hydrogen Fuel System
- Memorandum presenting the system analysis, design, and performance of a control system for an experimental flight-type hydrogen fuel system. The fuel system was designed to investigate some of the problems associated with the utilization of hydrogen as an aircraft fuel. Speed control of the engine was obtained by coupling the hydrogen regulator to the JP-4 fuel control.
- Flight Investigation of a Liquid Hydrogen Fuel System
- Memorandum presenting testing of a twin-engine light bomber modified to utilize hydrogen fuel in one of the two engines during flight at an altitude of 50,000 feet. Three completely successful flights were made using hydrogen fuel. Data are presented to show the effect of tank agitation on fuel pressure and fuel losses.
- Investigations on Reductions of Friction on Wings, in Particular by Means of Boundary Layer Suction
- Memorandum presenting investigation on reductions of friction on wings, especially by means of boundary-layer suction. The report is broken up into several sections, including: causes of transition, laminar profiles with the transition taking place, laminar boundary-layer suction, investigation of the laminar pressure increase, investigation of the slot flow for laminar boundary-layer suction with single slots, tests about keeping a boundary layer for high Reynolds laminar with the aid of boundary-layer suction, and an investigation of a slightly-cambered laminar suction profile of 10.5-percent thickness.
- Performance characteristics of an underslung vertical-wedge inlet with porous suction at Mach numbers of 0.63 and 1.5 to 2.0
- Performance characteristics of underslung vertical wedge inlet with porous suction at Mach numbers of 0.63 and 1.5 to 2.0.
- Summary and Analysis of Horizontal-Tail Contribution to Longitudinal Stability of Swept-Wing Airplanes at Low Speeds
- Report discussing available wind-tunnel data on low-speed horizontal-tail contribution to the static longitudinal stability of high-speed airplane configurations with unswept and sweptback wings. The effects of variations of tail position, wing plan form, airfoil section, trailing-edge flaps, stall-control devices, and ground interference on air-flow characteristics an tail contribution are also described.
- Low-Speed Wind-Tunnel Tests of a 1/8-Scale Model of the Bell D-188A VTOL Airplane
- Report discussing the results of an investigation to determine the low-speed power-off stability and control characteristics of a model of the Bell D-188A VTOL airplane. The static stability and control characteristics were generally satisfactory except above certain angles of attack and aileron effectiveness dropped off as the angle of attack was increased. Modifications for increasing the directional stability by altering the vertical tails are also described.
- Low-Speed Investigation of the Effect of Small Canard Surfaces on the Directional Stability of a Sweptback-Wing Fighter-Airplane Model
- Memorandum presenting a low-speed investigation in the free-flight tunnel to determine the effect of small canard surfaces on the directional stability of a fighter-airplane model with an aspect ratio of 3.4 and a 42 degree sweptback wing. The canard surfaces were found to be generally ineffective at angles of attack below 20 degrees.
- An Investigation of the Dynamic and Static Stability Characteristics of a Group of Specialized Store Configurations at Transonic Speeds
- Report presenting an investigation in the transonic tunnel to determine the dynamic and static stability characteristics of the Mark-6, Mark-4, TX-13, and Mark-5 special weapons and the effects of modifications of them for a range of Mach numbers.
- Wind-Tunnel Investigation at Low Speed of the Yawing Stability Derivatives of a 1/10-Scale Model of the Douglas A4D-1 Airplane
- Report discussing testing of a model of the Douglas A4D-1 to determine its low-speed yawing stability derivatives. The model was tested in clean and landing configurations with horizontal and vertical tails on and off and an investigation into the effect of slats and flaps on the wing-alone derivatives.
- Development of a Supersonic Area Rule and an Application to the Design of a Wing-Body Combination Having High Lift-to-Drag Ratios
- Report presenting a concept for interrelating the wave drag of wing-body combinations at moderate supersonic speeds with axial distributions of cross-sectional area has been developed. Details of preliminary experiments meant to test the concept are also provided.
- Natural Icing of an Axial-Flow Turbojet Engine in Flight for a Single Icing Condition
- Memorandum presenting an investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. A description of the change over time in tail-pipe temperature, engine jet thrust, fuel flow, ice collection, and acceleration qualities are provided.
- Preliminary Results of Natural Icing of an Axial-Flow Turbojet Engine
- Memorandum presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Tail-pipe temperature increased from 761 to 1065 degrees Fahrenheit and the jet thrust decreased from 1234 to 910 pounds during a period of 45 minutes in icing. No general conclusions can be reached from the data because the icing condition was relatively light.
- Icing and De-Icing of a Propeller with Internal Electric Blade Heaters
- "An investigation has been made in the NACA Cleveland icing research tunnel to determine the de-icing effectiveness of an experimental configuration of an Internal electric propeller-blade heater. Two atmospheric Icing conditions and two propeller operating conditions were Investigated in experiments with unheated blades and with heat applied to the blades both continuously and cyclically. Data are presented to show the effect of propeller speed, ambient air temperature and liquid-water concentration, and the duration of the heat-on and cycle times on the power requirements and de-icing performance of the blade heaters" (p. 1).
- Transonic Wind-Tunnel Investigation of Static-Pressure Fluctuations in Duct of a Scale Inlet Model of a Supersonic Fighter-Bomber Airplane
- Report presenting a transonic investigation of the static-pressure fluctuations in the left duct of a scale inlet model of a supersonic fighter-bomber airplane in the transonic tunnel. Results regarding amplitude characteristics of pressure fluctuations, power-spectral analyses, and flow distortions at compressor face are provided.
- Preliminary Analysis of Performance of Turbojet Engines Used as Pumps for Boundary-Layer Control
- Memorandum presenting a determination of the effects on engine performance of using turbojet engines for boundary-layer control by suction at the engine inlet or by bleeding air from the compressor outlet for three current production engines. Results regarding bleed, suction, and variable-area turbine are provided.
- Aerodynamic Characteristics at a Mach Number of 6.8 of Two Hypersonic Missile Configurations, One With Low-Aspect-Ratio Cruciform Fins and Trailing-Edge Flaps and One With a Flared Afterbody and All-Movable Controls
- Report presenting an investigation to determine the aerodynamic characteristics in pitch at a Mach number of 6.8 of hypersonic missile configurations with cruciform trailing-edge flaps and all-movable control surfaces. Testing indicated that all-movable controls on the flared-afterbody model should be capable of producing much larger values of trim lift and of normal acceleration than the trailing-edge-flap configuration. Some of the configurations tested include body alone, body with 5 degree fins and trailing-edge flaps, and body with 10 degree flare and all-movable controls.
- Investigation of a 1/22-Scale Model of the Republic F-105 Airplane in the Langley 8-Foot Transonic Tunnel: Lateral, Directional, and Additional Longitudinal Static Stability and Control
- Report presenting an investigation of the aerodynamic characteristics of various configurations of the Republic F-105 at Mach numbers from 0.60 to 1.13. The primary focus of this report are the static lateral and directional stability and control characteristics of the model. Results regarding force and moment results, longitudinal characteristics, lateral and directional characteristics.
- A Method for Numerically Calculating the Area and Distribution of Water Impingement on the Leading Edge of an Airfoil in a Cloud
- Note presenting a method for determining, by step-by-step integration, the trajectories of water drops around any body in two-dimensional flow for which the streamline velocity components are known or can be computed. The equations are presented in general form and then, to illustrate the procedure, water-drop trajectories are calculated about a 12-percent-thick symmetrical Joukowski profile chosen to simulate an NACA 0012 section. The method provides a means for the relatively rapid calculation of the trajectory of a single drop without the utilization of a differential analyzer.
- Preliminary Results of Heat Transfer from a Stationary and Rotating Ellipsoidal Spinner
- "Convective heat-transfer coefficients in dry air were obtained for an ellipsoidal spinner of 30-inch maximum diameter for both stationary and rotating operation over a range of conditions including airspeeds up to 275 miles per hour, rotational speeds up to 1200 rpm, and angles of attack of zero and 4 degrees. The results are presented in terms of Nusselt numbers, Reynolds numbers, and convective heat-transfer coefficients. The studies included both uniform heating densities over the spinner and uniform surface temperatures" (p. 1).
- Theoretical Investigation of Submerged Inlets at Low Speeds
- From Summary: "The general characteristics of the flow field in a submerged air inlet are investigated by theoretical, wind-tunnel, and visual-flow studies. Equations are developed for calculating the laminar and turbulent boundary-layer growth along the ramp floor for parallel, divergent, and convergent ramp walls, and a general equation is derived relating the boundary-layer pressure losses to the boundary-layer thickness. It is demonstrated that the growth of the boundary layer on the floor of the divergent-ramp inlet is retarded and that a vortex pair is generated in such an inlet."
- High Efficiency of Seaplanes
- A table is presented which includes data for calculating the index of efficiency. The author uses this data to conclude that seaplanes cannot be considered inferior to terrestrial airplanes.
- Problem of Landing
- The author discusses various aspects of landing aircraft such as the actual process of touchdown and the problems associated with the tail skid touching the ground before the landing gear.
- Calculation of Wing Spars
- A simplified formula for calculating wing spars is presented.
- Calculation of Wing Spars
- The author presents a comparison and combination of the numerical and geometrical determinations of the maximum M, when calculating the maximum bay moment.
- Large German airship stations
- "It is profitable to examine the organization and equipment of the German airship stations. The stations best adapted for serving as the basis of this study were chiefly constructed by the German Navy, during the war, for exclusively military purposes and do not therefore entirely satisfy the conditions of exploitation required for a civilian air service. The requisite modifications for satisfying the latter conditions may nevertheless be readily determined according to circumstances" (p. 1).
- Shape and Strength of Seaplane Under-Structures With Special Regard to Seaworthiness
- This report presents experiments and calculations for the purpose of determining the landing gear requirements upon the water. Moving pictures are given which furnish data and also may give both the magnitude and direction of the forces acting. Different classes of seaplanes are examined and proposals for calculation instructions are given.
- Moments of Cambered Round Bodies
- Results are presented for the moments and position of force centers of a series of cambered round bodies derived from a torpedo-like body of revolution. The effects of placing fins on the rear of the body of revolution are also included.
- The Problem of the Turbo-Compressor
- "In terminating the study of the adaptation of the engine to the airplane, we will examine the problem of the turbo-compressor, the first realization of which dates from the war; this will form an addition to the indications already given on supercharging at various altitudes. This subject is of great importance for the application of the turbo-compressor worked by the exhaust gases. Assuming that the increase of pressure in the admission manifold is the same in both cases, the pressure in the exhaust manifold would be greater in the case in which the compressor is worked by the exhaust gas and there would result a certain reduction of engine power which we must be able to calculate" (p. 1).
- The Employment of Airships for the Transport of Passengers: Indications on the Maximum Limits of Their Useful Load, Distance Covered, Altitude and Speed
- It was a conclusion of this detailed study of the practicality of using airships for carrying passengers that, although slow, airships are capable of carrying useful loads over long distances. However, it is noted that there is a certain limit to the advantages of large cubature. Beyond a certain point, the maximum altitude of the airship goes on decreasing, in spite of the fact that the range of action in the horizontal plane and the useful load go on increasing. The possibility of rapid climb is an essential factor of security in aerial navigation in the case of storms, as is velocity.
- Test of Oil Scraper Piston Ring and Piston Fitted With Oil Drain Holes
- Tests were conducted to determine whether or not a properly located and properly designed oil scraper piston ring, installed on a piston provided with oil drain holes of sufficient area, would prevent the excessive oiling of the Liberty engine, particularly with the engine running at idling speed with full oil pressure. Results showed that excessive oiling was in fact prevented. It is strongly recommended that scraper rings and pistons be adopted for aircraft engines.
- A New Method of Testing in Wind Tunnels
- Now, in existing wind tunnels, using a horsepower of 100 to 300, the models are generally made to a 1/10 scale and the speed is appreciably lower than the speeds currently attained by airplanes. The Reynolds number realized is thus 15 to 25 times smaller than that reached by airplanes in free flight, while the ratio of speed to the velocity of sound is between a third and three quarters of the true ratio. The necessary increases in either the diameter of the wind tunnel or the velocity of the airstream are too costly.
- The twisted wing with elliptic plan form
- A method for computing the aerodynamic induction of wings with elliptic plan form if arbitrarily twisted.
- Soaring Flight in Guinea
- Report discusses information obtained from studying large birds that fly by soaring, which involves using the wind without moving their wings. An Egyptian vulture and African white-backed vulture were observed and their relative air speed, upward air velocity, lift, and drag were noted. The experimental methods for measuring these values are described.
- An instrument for recording the position of airplane control surfaces
- 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.
- Increase in Maximum Pressures Produced by Preignition in Internal Combustion Engines
- Report discusses the calculations that can be used to show why pressures inside an engine during preignition are higher than average. This information can be used to design a safer engine that is able to contain the increased pressure and heat generated during preignition.
- Theory of Lifting Surfaces, Part 2
- A mathematical model is presented towards a theory of lifting and resistance on wings. It consists hide of a theory of multiplanes, conditions of flow at a great distance from the wing, lifting systems of minimum resistance, and free stream and stream limited by walls.
- Stability of Ballistic Reentry Bodies
- Report discussing various features of the stability of ballistic reentry shapes, including considerations for ballistic-missile and manned-satellite reentry capsules. Attainment of satisfactory stability of reentry bodies with subsonic terminal velocities was not found to be too difficult, but undesirable features that may cause marginal stability characteristics may be introduced in an effort to minimize weight. Reentry bodies with supersonic terminal velocities have fewer stability issues.
- Flight, Analog-Simulator, and Analytical Studies of an Automatically Controlled Interceptor Which Uses a Bank-Angle-Error Computer for Lateral Commands
- Report presenting the tracking performance of an automatically controlled interceptor in which the deflection channel incorporated a bank-angle-error computer that commanded rolling velocities of the interceptor proportional to the computed bank-angle errors. Results regarding gravity terms included in bank-angle-error computation and a comparison of modified system using bank-angle-error computer with the prototype system are provided.
- Experimental Investigation of Air-Cooled Turbine Blades in Turbojet Engine 2: Rotor Blades With 15 Fins in Cooling-Air Passages
- Report presenting an investigation to experimentally determine the effectiveness of air-cooling several configurations of turbine blades in a turbojet engine. The results of the second blade configuration, which consists of a hollow blade shell with 15 fins inserted, are provided. The factors involved in the design of the blade configuration are also included.
- Radiant Heat Transfer From Flames in a Single Tubular Turbojet Combuctor
- Memorandum presenting an investigation to determine the energy transfer by thermal radiation from the flame of a single tubular turbojet-engine combustor to the combustor liner. The effects of variations in combustor inlet-air pressure, fuel-air ratio, and air mass flow on the transfer of radiant energy were studied.
- Cooling Characteristics of a Transpiration-Cooled Afterburner With a Porous Wall of Brazed and Rolled Wire Cloth
- Memorandum presenting cooling data for a transpiration-cooled afterburner with a porous combustion-chamber wall of brazed and rolled wire cloth for a range of exhaust-gas temperatures, total flow ratio of cooling air to combustion gas, and pressure altitudes. Maximum wall temperatures based on the cooling correlation were determined for a porous wall of uniform permeability at sea-level takeoff and for several flight Mach numbers. Results regarding typical data, cooling correlation, transpiration-cooling performance, comparison of transpiration and forced-convection cooling, and pressure environment of wire cloth are provided.
- Interpretation of boundary-layer pressure-rake data in flow with a detached shock
- From Summary: "A procedure is presented for determining boundary-layer quantities from pressure-rake data, which include the combined effects of viscous and shock losses. The problem is analyzed using schileren photographs of the shock configuration, the continuity of mass relationship, and the characteristics of the turbulent boundary layer that its outer edge is defined by a rapid change in slope in the Mach-number profiles in the vicinity of the edge."
- Relation of Turbojet Propulsion System Development to the Strategic Bomber Mission
- Memorandum presenting a generalized analysis of the effects of turbojet propulsion system development and fuel selection on ability of a strategic bomber to perform desired and minimum missions. The variation of bomber performance using a hydrocarbon, boron, or nuclear fuel is discussed.
- An Investigation of the Afterbody Pressure Distribution and Fin Loading Characteristics of a Specialized Store Configuration at Transonic Speeds
- Report presenting an investigation in the transonic pressure tunnel to determine the afterbody pressure distribution and fin loading characteristics of two configurations of the TX-21 special weapon. The only different in the two configurations was the nose contour, with one having a hemispherical-flat shape and one with a double-radius ogive-flat shape. Results regarding the pressure port, fin loads, and force measurements are provided.
- Analysis of rocket, ramjet, and turbojet engines for supersonic propulsion of long-range missiles. 3: Ramjet engine performance
- Report presenting ramjet engine performance data over a range of engine design variables to permit selection and evaluation of a ramjet engine configuration for a long-range supersonic missile. Results include engine thrust, drag, fuel consumption, area ratios, and weight, and are suitable for use in design studies of missiles incorporating either internally or externally mounted ramjet engines.
- Measurement and Analysis of Turbulent Flow Containing Periodic Flow Fluctuations
- Memorandum presenting techniques for the measurement of the energy spectrum of flow fluctuations in both axial and lateral flow directions. A simple spectrum analysis is presented by which quantitative distinction may be made between turbulence and the flow disturbances associated with sound waves in ducts. Results regarding the measurement and analysis of turbulent-flow fields containing random and periodic flow fluctuations, effect of random sound disturbances on turbulence spectrum, and effect of combustion on combustor approach-stream spectrum are provided.
- Experimental and Analytical Study of Balanced-Diaphragm Fuel Distributors for Gas-Turbine Engines
- "A method of distributing fuel equally to a plurality of spray nozzles in a gas-turbine engine by means of balanced-diaphragm fuel distributors is presented. The experimental performance of three of eight possible distributor arrangements are discussed. An analysis of all eight arrangements is included. Criterions are given for choosing a fuel-distributor arrangement to meet specific fuel-system requirements of fuel-distribution accuracy, spray-nozzle pressure variations, and fuel-system pressures" (p. 1).