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Accuracy of airspeed measurements and flight calibration procedures

Description: From Summary: "The sources of error that may enter into the measurement of airspeed by pitot-static methods are reviewed in detail together with methods of flight calibration of airspeed installations. Special attention is given to the problem of accurate measurements of airspeed under conditions of high speed and maneuverability required of military airplanes." (author).
Date: 1948
Creator: Huston, Wilber B
Partner: UNT Libraries Government Documents Department

The additional-mass effect of plates as determined by experiments

Description: From Introduction: "The apparent increase in the inertia properties of a body moving in a fluid medium has been called the additional-mass effect. This report presents a resume of test procedures and results of experimental determinations of the additional-mass effect of flat plates. In addition to data obtained from various foreign sources and from a NACA investigation in 1933, the results of tests recently conducted by the National Advisory Committee for Aeronautics are included."
Date: 1941
Creator: Gracey, William
Partner: UNT Libraries Government Documents Department

Aerodynamic and hydrodynamic tests of a family of models of flying hulls derived from a streamline body -- NACA model 84 series

Description: Report discussing a series of related forms of flying-boat hulls representing various degrees of compromise between aerodynamic and hydrodynamic requirements was tested in Langley Tank No. 1 and in the Langley 8-foot high-speed tunnel. The purpose of the investigation was to provide information regarding the penalties in water performance resulting from further aerodynamic refinement and, as a corollary, to provide information regarding the penalties in range or payload resulting from the retention of certain desirable hydrodynamic characteristics. The information should form a basis for over-all improvements in hull form.
Date: 1943?
Creator: Parkinson, John B; Olson, Roland E; Draley, Eugene C & Luoma, Arvo A
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of horizontal tail surfaces

Description: From Summary: "Collected data are presented on the aerodynamic characteristics of 17 horizontal tail surfaces including several with balanced elevators and two with end plates. Curves are given for coefficients of normal force, drag, and elevator hinge moment. A limited analysis of the results has been made. The normal-force coefficients are in better agreement with the lifting-surface theory of Prandtl and Blenk for airfoils of low aspect ratio than with the usual lifting-line theory. Only partial agreement exists between the elevator hinge-moment coefficients and those predicted by Glauert's thin-airfoil theory."
Date: 1940
Creator: Silverstein, Abe & Katzoff, S
Partner: UNT Libraries Government Documents Department

Air-consumption parameters for automatic mixture control of aircraft engines

Description: From Introduction: "The purpose of this analysis was to investigate the use of a function of intake-manifold pressure, exhaust back pressure, intake manifold temperature, and engine speed in place of a venturi as a means of measuring engine air consumption and to determine if this function is suitable for automatic mixture control."
Date: September 1, 1944
Creator: Shames, Sidney J
Partner: UNT Libraries Government Documents Department

Analysis and modification of theory for impact of seaplanes on water

Description: An analysis of available theory on seaplane impact and a proposed modification thereto are presented. In previous methods the overall momentum of the float and virtual mass has been assumed to remain constant during the impact but the present analysis shows that this assumption is rigorously correct only when the resultant velocity of the float is normal to the keel. The proposed modification chiefly involves consideration of the fact that forward velocity of the seaplane float causes momentum to be passed into the hydrodynamic downwash (an action that is the entire consideration in the case of the planing float) and consideration of the fact that, for an impact with trim, the rate of penetration is determined not only by the velocity component normal to the keel but also by the velocity component parallel to the keel, which tends to reduce the penetration. Experimental data for planing, oblique impact, and vertical drop are used to show that the accuracy of the proposed theory is good.
Date: January 1, 1945
Creator: Mayo, Wilbur L
Partner: UNT Libraries Government Documents Department

Analysis and prediction of longitudinal stability of airplanes

Description: An analysis has been made of the longitudinal stability characteristics of 15 airplanes as determined in flight. In the correlation of satisfactory and unsatisfactory characteristics with determined values, the derivative that expresses the ratio of static-restoring moments to elevator-control moments was found to represent most nearly the stability characteristics appreciated by the pilots. The analysis was extended to study the effects of various design features on the observed stability characteristics. Design charts and data are included that show the effects on longitudinal stability of relative positions of wing and tail, fuselage size and location, engine nacelles, and horizontal-tail arrangements.
Date: January 1, 1941
Creator: Gilruth, R R & White, M D
Partner: UNT Libraries Government Documents Department

Analysis of cooling limitations and effect of engine-cooling improvements on level-flight cruising performance of four-engine heavy bomber

Description: The NACA has developed means, including an injection impeller and ducted head baffles, to improve the cooling characteristics of the 3350-cubic-inch-displacement radial engines installed in a four-engine heavy bomber. The improvements afforded proper cooling of the rear-row exhaust-valve seats for a wide range of cowl-flap angles, mixture strengths, and airplane speeds. The results of flight tests with this airplane are used as a basis for a study to determine the manner and the extent to which the airplane performance was limited by engine cooling. By means of this analysis for both the standard airplane and the airplane with engine-cooling modifications, comparison of the specific range at particular conditions and comparison of the cruising-performance limitations was made.
Date: March 14, 1946
Creator: Marble, Frank E; Miller, Marlon A & Bell, E Barton
Partner: UNT Libraries Government Documents Department

Analysis of effect of basic design variables on subsonic axial-flow-compressor performance

Description: A blade-element theory for axial-flow compressors has been developed and applied to the analysis of the effects of basic design variables such as Mach number, blade loading, and velocity distribution on compressor performance. A graphical method that is useful for approximate design calculations is presented. The relations among several efficiencies useful in compressor design are derived and discussed. The possible gains in useful operating range obtainable by the use of adjustable stator blades are discussed and a rapid approximate method of calculating blade-angle resettings is shown by an example. The relative Mach number is shown to be a dominant factor in determining the pressure ratio.
Date: November 26, 1947
Creator: Sinnette, John T , Jr
Partner: UNT Libraries Government Documents Department

Analysis of heat and compressibility effects in internal flow systems and high-speed tests of a ram-jet system

Description: An analysis has been made by the NACA of the effects of heat and compressibility in the flow through the internal systems of aircraft. Equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained.
Date: July 21, 1942
Creator: Becker, John V & Baals, Donald D
Partner: UNT Libraries Government Documents Department

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

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.
Date: July 31, 1946
Creator: Pinkel, I Irving & Shames, Harold
Partner: UNT Libraries Government Documents Department

An analysis of life expectancy of airplane wings in normal cruising flight

Description: In order to provide a basis for judging the relative importance of wing failure by fatigue and by single intense gusts, an analysis of wing life for normal cruising flight was made based on data on the frequency of atmospheric gusts. The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed. The procedure selected for the analysis is believed to be simple and reasonably accurate, though slightly conservative.
Date: January 1, 1945
Creator: Putnam, Abbott A
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

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.
Date: January 1, 1947
Creator: Goldstein, Arthur W
Partner: UNT Libraries Government Documents Department

Analysis of performance of jet engine from characteristics of components II : interaction of components as determined from engine operation

Description: In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.
Date: January 1, 1949
Creator: Goldstein, Arthur W; Alpert, Sumner; Beede, William & Kovach, Karl
Partner: UNT Libraries Government Documents Department

Analysis of spark-ignition engine knock as seen in photographs taken at 200,000 frames per second

Description: A motion picture of the development of knock in a spark-ignition engine is presented, which consists of 20 photographs taken at intervals of 5 microseconds, or at a rate of 200,000 photographs per second, with an equivalent wide-open exposure time of 6.4 microseconds for each photograph. A motion picture of a complete combustion process, including the development of knock, taken at the rate of 40,000 photographs per second is also presented to assist the reader in orienting the photographs of the knock development taken at 200,000 frames per second.
Date: January 1, 1946
Creator: Miller, Cearcy D; Olsen, H Lowell; Logan, Walter O , Jr & Osterstrom, Gordon E
Partner: UNT Libraries Government Documents Department

An analysis of supersonic aerodynamic heating with continuous fluid injection

Description: An analysis of the steady-state aerodynamic heating problem at high-supersonic speeds is made for two-dimensional flows with laminar boundary layers. The aerodynamic heating is shown to be reduced substantially by injecting a small amount of coolant through a porous surface into the boundary layer. The analysis includes calculations of the cooling requirements and equilibrium surface temperatures for flat plates and for an equilibrium surface temperatures for flat plates and for flat porous surfaces with several rates of fluid injection at Mach numbers from 5 to 15 and altitudes from sea level to 200,000 feet. Some calculations of the skin friction are also included.
Date: September 29, 1949
Creator: Klunker, E G & Ivey, H Reese
Partner: UNT Libraries Government Documents Department

An analysis of the dissipation of heat in conditions of icing from a section of the wing of the C-46 airplane

Description: A method is given for calculating the temperature that a surface, heated internally by air, will assume in specified conditions of icing. The method can be applied generally to predict the performance, under conditions of icing, of the thermal system for protecting aircraft. Calculations have been made for a section of the wing of the C-46 airplane, and the results agree closely with the temperature measured. The limit of protection when the temperature of the surface reaches 32 degrees F., has been predicted for the leading edge. The temperature of the surface in conditions of icing with air at 0 degree F. also has been calculated. The effect of kinetic heating and the effect of the concentration of free water and size of droplet in the cloud are demonstrated.
Date: 1945?~
Creator: Hardy, J K
Partner: UNT Libraries Government Documents Department

An analysis of the full-floating journal bearing

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.
Date: January 1, 1947
Creator: Shaw, M C & Nussdorfer, T J , Jr
Partner: UNT Libraries Government Documents Department

An analysis of the stability of an airplane with free controls

Description: Report presents the results of an investigation made of the essentials to the stability of an airplane with free control surfaces. Calculations are based on typical airplane characteristics with certain factors varied to cover a range of current designs. Stability charts are included to show the limiting values of the aerodynamic hinge moments and the weight hinge moments of the control surfaces for various positions of the center of gravity of the airplane and for control systems with various moments of inertia. The effects of reducing the chord and of eliminating the floating tendency of the surface, of changing the wing loading, and of decreasing the radius of gyration of the airplane are also indicated. An investigation has also been made of the nature of the motion of the airplane with controls free and of the modes of instability that may occur.
Date: August 15, 1940
Creator: Jones, Robert T & Cohen, Doris
Partner: UNT Libraries Government Documents Department

Analysis of variation of piston temperature with piston dimensions and undercrown cooling

Description: A theoretical analysis is presented that permits estimation of the changes in piston-temperature distribution induced by variations in the crown thickness, the ring-groove-pad thickness, and the undercrown surface heat-transfer coefficient. The analysis consists of the calculation of operating temperatures at various points in the piston body on the basis of the experimentally determined surface heat-transfer coefficients and boundary-region temperatures, as well as arbitrarily selected surface coefficients. Surface heat-transfer coefficients were estimated from the internal temperature gradients obtained by hardness surveys of aluminum pistons that had been operated under severe conditions in a liquid-cooled, single-cylinder, 5 1/2 by 6-inch test engine.
Date: January 15, 1948
Creator: Sanders, J C & Schramm, W B
Partner: UNT Libraries Government Documents Department

Analysis of wind-tunnel stability and control tests in terms of flying qualities of full-scale airplanes

Description: The analysis of results of wind-tunnel stability and control tests of powered airplane models in terms of the flying qualities of full-scale airplanes is advocated. In order to indicated the topics upon which comments are considered desirable in the report of a wind-tunnel stability and control investigation and to demonstrate the nature of the suggested analysis, the present NACA flying-qualities requirements are discussed in relation to wind-tunnel tests. General procedures for the estimation of flying qualities from wind-tunnel tests are outlined.
Date: April 1, 1943
Creator: Kayten, Gerald G
Partner: UNT Libraries Government Documents Department

An analytical method of estimating turbine performance

Description: A method is developed by which the performance of a turbine over a range of operating conditions can be analytically estimated from the blade angles and flow areas. In order to use the method, certain coefficients that determine the weight flow and the friction losses must be approximated. The method is used to calculate the performance of the single-stage turbine of a commercial aircraft gas-turbine engine and the calculated performance is compared with the performance indicated by experimental data. For the turbine of the typical example, the assumed pressure losses and the tuning angles give a calculated performance that represents the trends of the experimental performance with reasonable accuracy. The exact agreement between analytical performance and experimental performance is contingent upon the proper selection of a blading-loss parameter.
Date: January 1, 1949
Creator: Kochendorfer, Fred D & Nettles, J Cary
Partner: UNT Libraries Government Documents Department

An apparatus for measuring rates of discharge of a fuel-injection system

Description: A portable apparatus for rapidly determining rates of discharge of a fuel-injection system is described. Satisfactory operation of this apparatus with injection-pump speeds up to 2400 r.p.m was obtained. Rate-of-discharge tests were made with several cam-plunger-valve injection systems with long injection tubes. A check valve designed to reduce secondary discharges was tested. This check valve was operated with injection-pump speeds up to 2400 r.p.m without the occurrence of large secondary discharges.
Date: March 24, 1941
Creator: Dutee, Francis J
Partner: UNT Libraries Government Documents Department

An apparatus for varying effective dihedral in flight with application to a study of tolerable dihedral on a conventional fighter airplane

Description: An apparatus for varying effective dihedral in flight by means of servo actuation of the ailerons in response to sideslip angle is described. The results of brief flight tests of the apparatus on a conventional fighter airplane are presented and discussed. The apparatus is shown to have satisfactory simulated a wide range of effective dihedral under static and dynamic conditions. The effects of a small amount of servo lag are shown to be measurable when the apparatus is simulating small negative values of dihedral. However, these effects were not considered by the pilots to give the airplane an artificial feel. The results of an investigation employing the apparatus to determine the tolerable (safe for normal fighter operation) range of effective dihedral on the test airplane are presented.
Date: August 24, 1949
Creator: Kauffman, William M; Liddell, Charles J , Jr; Smith, Allan & Van Dyke, Rudolph D , Jr
Partner: UNT Libraries Government Documents Department