Technical Report Archive & Image Library (TRAIL) - 4,107 Matching Results

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Investigation of heat transfer from a stationary and rotating ellipsoidal forebody of fineness ratio 3

Description: From Summary: "The convective heat transfer from the surface of an ellipsoidal forebody of fineness ratio 3 and 20-inch maximum diameter was investigated in clear air for both stationary and rotating operation over a range of conditions including air speeds up to 240 knots, rotational speeds up to 1200 rpm, and angles of attack of 0 deg, 3 deg, and 6 deg. The results are presented in the form of heat-transfer coefficients and the correlation of Nusselt and Reynolds numbers. Both a uniform surfa… more
Date: November 1956
Creator: Lewis, James P. & Ruggeri, Robert S.
Partner: UNT Libraries Government Documents Department
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Investigation of Heat Transfer from a Stationary and Rotating Conical Forebody

Description: From Summary: "The convective heat transfer from the surface of a conical forebody having a hemispherical nose, an included angle of approximately 30 deg, and. a maximum diameter of 18.9 inches was investigated in a wind tunnel for both stationary and. rotating operation. The range of test conditions included free-stream velocities up to 400 feet per second, rotational speeds up to 1200 rpm, and. angles of attack of 0 deg and 6 deg. Both a uniform surface temperature and a uniform heater input … more
Date: October 1957
Creator: Ruggeri, Robert S. & Lewis, James P.
Partner: UNT Libraries Government Documents Department
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The Calculation of the Heat Required for Wing Thermal Ice Prevention in Specified Icing Conditions

Description: Note presenting a verification of previously derived equations for calculating the rate of heat transfer from airfoils in icing conditions, which have come about as a result of an investigation of the meteorological conditions conducive to the formation of ice on aircraft and a study of the process of airfoil thermal ice prevention. The results indicated that knowledge of these components has increased to a point where the design of heated wings on a fundamental, wet-air basis can now be undert… more
Date: December 1947
Creator: Neel, Carr B., Jr.; Bergrun, Norman R.; Jukoff, David & Schlaff, Bernard A.
Partner: UNT Libraries Government Documents Department
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An Empirical Method Permitting Rapid Determination of the Area, Rate and Distribution of Water-Drop Impingement on an Airfoil of Arbitrary Section at Subsonic Speeds

Description: "An empirical method for the determination of the area, rate, and distribution of water-drop impingement on airfoils of arbitrary section is presented. The procedure represents an initial step toward the development of a method which is generally applicable in the design of thermal ice-prevention equipment for airplane wing and tail surfaces. Results given by the proposed empirical method are expected to be sufficiently accurate for the purpose of heated-wing design, and can be obtained from a … more
Date: September 1951
Creator: Bergrun, Norman R.
Partner: UNT Libraries Government Documents Department
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A Method for Numerically Calculating the Area and Distribution of Water Impingement on the Leading Edge of an Airfoil in a Cloud

Description: 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 calculatio… more
Date: August 1947
Creator: Bergrun, Norman R.
Partner: UNT Libraries Government Documents Department
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Impingement of droplets in 90 degree elbows with potential flow

Description: Trajectories were determined for droplets in air flowing through 90 deg elbows especially designed for two-dimensional potential motion with low pressure losses. The elbows were established by selecting as walls of each elbow two streamlines of the flow field produced by a complex potential function that establishes a two-dimensional flow around a 90 deg bend. An unlimited number of elbows with slightly different shapes can be established by selecting different pairs of streamlines as walls. Th… more
Date: September 1953
Creator: Hacker, Paul T.; Brun, Rinaldo J. & Boyd, Bemrose
Partner: UNT Libraries Government Documents Department
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Impingement of Water Droplets on NACA 65A004 Airfoil and Effect of Change in Airfoil Thickness from 12 to 4 Percent at 4 deg Angle of Attack

Description: From Summary: "The trajectories of droplets in the air flowing past an NACA 65A004 airfoil at an angle of attack of 4 deg were determined. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and presented to cover a large range of flight and atmospheric conditions. The effect of a change in airfoil thickness from 12 to 4 percent at 4 deg angle… more
Date: November 1953
Creator: Brun, Rinaldo J.; Gallagher, Helen M. & Vogt, Dorothea E.
Partner: UNT Libraries Government Documents Department
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Impingement of Water Droplets on NACA 65(1)-208 and 65(1)-212 Airfoils at 4 Degrees Angle of Attack

Description: "The trajectories of droplets in the air flowing past NACA 65(1)-208 airfoil and an NACA 65(1)-212 airfoil, both at an angle of attack of 4 degrees, were determined. The amount of water in droplet form impinging on the airfoils, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface affected were calculated from the trajectories and are presented. The amount, extent, and rate of impingement of the NACA 65(1)-208 airfoil are compared with the re… more
Date: May 1953
Creator: Brun, Rinaldo J.; Gallagher, Helen M. & Vogt, Dorothea E.
Partner: UNT Libraries Government Documents Department
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Impingement of Water Droplets on a Cylinder in an Incompressible Flow Field and Evaluation of Rotating Multicylinder Method for Measurement of Droplet-Size Distribution, Volume-Median Droplet-Size, and Liquid-Water Content in Clouds

Description: Note presenting an evaluation of the rotating method for the measurement of droplet-size distribution, volume-median droplet size, and liquid-water content in clouds, which showed that small uncertainties in basic data eliminate the distinction between cloud droplet-size distributions and are a source of large errors in the determination of the droplet size. Matching curves for obtaining droplet-size distribution, volume-median droplet size, and liquid-water content from flight data were comput… more
Date: March 1953
Creator: Brun, Rinaldo J. & Mergler, Harry W.
Partner: UNT Libraries Government Documents Department
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Impingement of Cloud Droplets on Aerodynamic Bodies as Affected by Compressibility of Air Flow Around the Body

Description: Note presenting the computation of the trajectories of water droplets in a compressible-air flow field around a cylinder using a mechanical analog. The results of the calculations at approximately the flight critical Mach number were compared with calculations of trajectories in an incompressible flow field. Results regarding the extension of cylinder results to airfoils are provided.
Date: March 1953
Creator: Brun, Rinaldo J.; Serafini, John S. & Gallagher, Helen M.
Partner: UNT Libraries Government Documents Department
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A Method for Determining Cloud-Droplet Impingement on Swept Wings

Description: From Summary: "The general effect of wing sweep on cloud-droplet trajectories about swept wings of high aspect ratio moving at subsonic speeds is discussed. A method of computing droplet trajectories about yawed cylinders and swept wings is presented, and illustrative droplet trajectories are computed. A method of extending two-dimensional calculations of droplet impingement on nonswept wings to swept wings is presented."
Date: April 1953
Creator: Dorsch, Robert G. & Brun, Rinaldo J.
Partner: UNT Libraries Government Documents Department
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Impingement of Water Droplets on an Ellipsoid with Fineness Ratio 5 in Axisymmetric Flow

Description: "The presence of radomes and instruments that are sensitive to water films or ice formations in the nose section of all-weather aircraft and missiles necessitates a knowledge of the droplet impingement characteristics of bodies of revolution. Because it is possible to approximate many of these bodies with an ellipsoid of revolution, droplet trajectories about an ellipsoid of revolution with a fineness ratio of 5 were computed for incompressible axisymmetric air flow. From the computed droplet t… more
Date: March 1954
Creator: Dorsch, Robert G.; Brun, Rinaldo J. & Gregg, John L.
Partner: UNT Libraries Government Documents Department
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Variation of Local Liquid-Water Concentration About and Ellipsoid of Fineness Ratio 5 Moving in a Droplet Field

Description: From Summary: "Trajectories of water droplets about an ellipsoid of revolution with a fineness ratio of 5 (which often approximates the shape of an aircraft fuselage or missile) were computed with the aid of a differential analyzer. Analyses of these trajectories indicate that the local concentration of liquid water at various points about an ellipsoid in flight through a droplet field varies considerably and under some conditions may be several times the free-stream concentration."
Date: July 1954
Creator: Dorsch, Robert G. & Brun, Rinaldo J.
Partner: UNT Libraries Government Documents Department
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Experimental Investigation of Sublimation of Ice at Subsonic and Supersonic Speeds and Its Relation to Heat Transfer

Description: "An experimental investigation was conducted in a 3.84- by 10-inch tunnel to determine the mass transfer by sublimation, heat transfer, and skin friction for an iced surface on a flat plate for Mach numbers of 0.4, 0.6, and 0.8 and pressure altitudes to 30,000 feet. Measurements of rates of sublimation were also made for a Mach number of 1.3 at a pressure altitude of 30,000 feet. The results show that the parameters of sublimation and heat transfer were 40 to 50 percent greater for an iced surf… more
Date: March 1954
Creator: Coles, Willard D. & Ruggeri, Robert S.
Partner: UNT Libraries Government Documents Department
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The Calculated and Measured Performance Characteristics of a Heated-Wire Liquid-Water-Content Meter for Measuring Icing Severity

Description: "Ground tests have been made of an instrument which, when assembled in a more compact form for flight installation, could be used to obtain statistical flight data on the liquid-water content of icing clouds and to provide an indication of icing severity. The sensing element of the instrument consists of an electrically heated wire which is mounted in the air stream. The degree of cooling of the wire resulting from evaporation of the impinging water droplets is a measure of the liquid-water con… more
Date: January 1952
Creator: Neel, Carr B. & Steinmetz, Charles P.
Partner: UNT Libraries Government Documents Department
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An Instrument Employing a Coronal Discharge for the Determination of Droplet-Size Distribution in Clouds

Description: From Summary: "A flight instrument that uses electric means for measuring the droplet-size distribution in above-freezing clouds has been devised and given preliminary evaluation in flight. An electric charge is placed on the droplets and they are separated aerodynamically according to their mass. Because the charge placed on the droplets is a. function of the droplet size, the size spectrum can 'be determined by measurement of the charge deposited on cylinders of several different sizes placed… more
Date: September 1951
Creator: Brun, Rinaldo J.; Levine, Joseph & Kleinknecht, Kenneth S.
Partner: UNT Libraries Government Documents Department
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Comparison of Three Multicylinder Icing Meters and Critique of Multicylinder Method

Description: "Three multicylinder cloud meters, fundamentally similar but differing in important details, were compared in use at the Mount Washington Observatory. Determinations of liquid water content were found to agree within the limits of the probable error, but the two instruments designed by the National Advisory Committee for Aeronautics indicated larger drop sizes than did the Observatory's instrument, apparently because of spurious ice catch on the rather rough surface of the larger cylinders. Com… more
Date: June 1952
Creator: Howell, Wallace E.
Partner: UNT Libraries Government Documents Department
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An Oil-Stream Photomicrographic Aeroscope for Obtaining Cloud Liquid-Water Content and Droplet Size Distributions in Flight

Description: "An airborne cloud aeroscope by which droplet size, size distribution, and liquid-water content of clouds can be determined has been developed and tested in flight and in wind tunnels with water sprays. In this aeroscope the cloud droplets are continuously captured in a stream of oil, which Is then photographed by a photomicrographic camera. The droplet size and size distribution can be determined directly from the photographs" (p. 1).
Date: January 1956
Creator: Hacker, Paul T.
Partner: UNT Libraries Government Documents Department
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A Probability Analysis of the Meteorological Factors Conducive to Aircraft Icing in the United States

Description: Note presenting meteorological icing data obtianed in flight in the United States that is analyzed statistically and used to develop methods for the determination of the various simultaneous combinations of the three basic icing parameters and the probability of exceeding any specified group of values of liquid-water content associated simultaneously with temperature and drop-diameter values. A mathematical basis is also provided for the future statistical analysis of meteorological icing data … more
Date: July 1952
Creator: Lewis, William & Bergrun, Norman R.
Partner: UNT Libraries Government Documents Department
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Comparison of Heat Transfer from Airfoil in Natural and Simulated Icing Conditions

Description: "An investigation of the heat transfer from an airfoil in clear air and in simulated icing conditions was conducted in the NACA Lewis 6- by 9-foot icing-research tunnel in order to determine the validity of heat-transfer data as obtained in the tunnel. This investigation was made on the same model NACA 65,2-016 airfoil section used in a previous flight study, under similar heating, icing, and operating conditions. The effect of tunnel turbulence, in clear air and in icing was indicated by the f… more
Date: September 1951
Creator: Gelder, Thomas F. & Lewis, James P.
Partner: UNT Libraries Government Documents Department
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A Method for Rapid Determination of the Icing Limit of a Body in Terms of the Stream Conditions

Description: "The effects of existing frictional heating were analyzed to determine the conditions under which ice formations on aircraft surfaces can be prevented. A method is presented for rapidly determining by means of charts the combination of-Mach number, altitude, and stream temperature which will maintain an ice-free surface in an icing cloud. The method can be applied to both subsonic and supersonic flow. The charts presented are for Mach numbers up to 1.8 and pressure altitudes from sea level to 4… more
Date: March 1953
Creator: Callaghan, Edmund E. & Serafini, John S.
Partner: UNT Libraries Government Documents Department
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Investigation of the Penetration of an Air Jet Directed Perpendicularly to an Air Stream

Description: Note presenting an experimental investigation to determine the penetration of a circular air jet directed perpendicularly to an air stream as a function of jet density, jet velocity, air-stream density, air-stream velocity, jet diameter, and distance downstream from the jet. The penetration was determined for nearly constant values of air-stream density at two tunnel velocities, four jet diameters, four positions downstream of the jet, and for a large range of jet velocities and densities.
Date: June 1948
Creator: Callaghan, Edmund E. & Ruggeri, Robert S.
Partner: UNT Libraries Government Documents Department
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Penetration of Air Jets Issuing from Circular, Square, and Elliptical Orifices Directed Perpendicularly to an Air Stream

Description: From Summary: "An experimental investigation was conducted to determine the penetration of air jets directed perpendicularly to an air stream. Jets issuing from circular, square, and elliptical orifices were investigated and the jet penetration at a position downstream of the orifice was determined- as a function of jet density, jet velocity, air-stream density, air-stream velocity, effective jet diameter, and orifice flow coeffIcient. The jet penetrations were determined for nearly constant va… more
Date: February 1950
Creator: Ruggeri, Robert S.; Callaghan, Edmund E. & Bowden, Dean T.
Partner: UNT Libraries Government Documents Department
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