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Investigations Relating to the Extension of Laminar Flow by Means of Boundary-Layer Suction Through Slots

Description: Note presenting experimental investigations of boundary-layer suction through slots as a means of increasing the extent of laminar flow on airfoil sections. The results show that, with the use of suitable slots, substantial increases in the extent of laminar flow can be achieved by boundary-layer control with only a small expenditure of power. Results regarding slot geometry and arrangement, suction slots in an unfavorable pressure gradient, suction slots in a favorable pressure gradient, and d… more
Date: October 1949
Creator: Loftin, Laurence K., Jr. & Burrows, Dale L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An Investigation Utilizing an Electrical Analogue of Cyclic Deicing of Hollow Steel Propellers with Internal Electric Heaters

Description: "A study has been made of the heating requirements for the cyclic de-icing of hollow steel propellers fitted with two types of internal electric heaters. Solutions to the transient-heat-flow equations depicting the cyclic de-icing of propellers were obtained by use of an electrical analogy. The study showed the impracticability of using an internal tubular heater and illustrated the advantages of employing an internal shoe-type heater, which distributes the heat more evenly to the blade surface… more
Date: October 1953
Creator: Neel, Carr B., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Ice Formations on Propeller Performance

Description: "Measurements of propeller efficiency loss due to ice formation are supplemented by an analysis to establish the magnitude of efficiency losses to be anticipated during flight in icing conditions. The measurements were made during flight in natural icing conditions; whereas the analysis consisted of an investigation of changes in blade-section aerodynamic characteristics caused by ice formation and the resulting propeller efficiency changes. Agreement in the order of magnitude of efficiency los… more
Date: October 1950
Creator: Neel, Carr B., Jr. & Bright, Loren G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of Icing Characteristics of Typical Light Airplane Engine Induction Systems

Description: "The icing characteristics of two typical light-airplane engine induction systems were investigated using the carburetors and manifolds of engines in the horsepower ranges from 65 to 85 and 165 to 185. The smaller system consisted of a float-type carburetor with an unheated manifold and the larger system consisted of a single-barrel pressure-type carburetor with an oil-jacketed manifold. Carburetor-air temperature and humidity limits of visible and serious Icing were determined for various engi… more
Date: February 1949
Creator: Coles, Willard D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of Icing of an Engine Cooling-Fan Installation

Description: Note presenting an investigation of the icing characteristics and means of ice protection of a typical radial-engine cooling-fan installation. The icing of the unprotected cooling-fan installation was found to present a serious operational problem. Results regarding icing, steam heat de-icing, alcohol de-icing, and electrical heat de-icing are provided.
Date: April 1947
Creator: Lewis, James P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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X-Ray Diffraction Study of the Internal Structure of Supercooled Water

Description: From Summary: "A Bragg X-ray spectrometer equipped with a volume-sensitive Geiger counter and Soller slits and employing filtered molybdenum Ka radiation was used to obtain a set of diffracted intensity curves as a Punction of angle for supercooled water. Diffracted intensity curves in the temperature region of 21 to -16 C were obtained. The minimum between the two main diffraction peaks deepened continuously with lowering temperature, indicating a gradual change in the internal structure of th… more
Date: October 1951
Creator: Dorsch, Robert G. & Boyd, Bemrose
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental Determination of Thermal Conductivity of Low-Density Ice

Description: "The thermal conductivity of low-density ice has been computed from data obtained in an experimental investigation of the heat transfer and mass transfer by sublimation for an iced surface on a flat plate in a high-velocity tangential air stream. The results are compared with data from several sources on the thermal conductivity of packed snow and solid glaze ice. The results show good agreement with the equations for the thermal conductivity of packed snow as a function of snow density. The ag… more
Date: March 1954
Creator: Coles, Willard D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Aerodynamic Effects Caused by Icing of an Unswept NACA 65A004 Airfoil

Description: From Summary: "The effects of ice formations on the section lift, drag, and pitching-moment coefficients of an unswept NACA 65A004 airfoil section of 6-foot chord were studied.. The magnitude of the aerodynamic penalties was primarily a function of the shape and size of the ice formation near the leading edge of the airfoil. The exact size and shape of the ice formations were determined photographically and found to be complex functions of the operating and icing conditions."
Date: February 1958
Creator: Gray, Vernon H. & von Glahn, Uwe H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation of Aerodynamic and Icing Characteristics of Recessed Fuel-Vent Configurations

Description: From Summary: "An investigation has been conducted in the NACA Cleveland icing research tunnel to determine the aerodynamic and icing characteristics of several recessed fuel-vent configurations. The vents were investigated aerodynamically to obtain vent-tube pressures and pressure distributions on the ramp surface as functions of tunnel-air velocity and angle of attack. Icing investigations were made to determine the vent-tube pressure losses for several icing conditions at tunnel-air velociti… more
Date: March 1949
Creator: Ruggeri, Robert S.; von Glahn, Uwe H. & Rollin, Vern G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Icing Limit and Wet-Surface Temperature Variation for Two Airfoil Shapes Under Simulated High-Speed Flight Conditions

Description: Note presenting an experimental study of the wet-surface temperature and stream conditions that result in ice-free surfaces for bodies in flight through icing clouds, and the results obtained are compared with values calculated using an analytical method. Two symmetrical airfoil models, one of diamond shape and the other of double-circular-arc contour, were used in the investigation. Results regarding the chordwise variation of pressure distribution, chordwise variation of recovery factor, the … more
Date: February 1955
Creator: Coles, Willard D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Flight Evaluation and Analysis of the Effect of Icing Conditions on the ZPG-2 Airship

Description: "A series of test flights was conducted by the U. S. Navy over a 3- year period to evaluate the effects of icing on the operation of the ZPG-2 airship. In supercooled. clouds, ice formed only on the forward edges of small protuberances and wires and presented no serious hazard to operation. Ice accretions of the glaze type which occurred in conditions described as freezing drizzle adversely affected various components to a somewhat greater extent" (p. 1).
Date: April 1958
Creator: Lewis, William & Perkins, Porter J., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Procedure for the Design of Air-Heated Ice-Prevention Systems

Description: A procedure proposed for use in the design of air-heated systems for the continuous prevention of ice formation on airplane components is set forth. Required heat-transfer and air-pressure-loss equations are presented, and methods of selecting appropriate meteorological conditions for flight over specified geographical areas and for the calculation of water-drop-impingement characteristics are suggested. In order to facilitate the design, a simple electrical analogue was devised which solves th… more
Date: June 1954
Creator: Neel, Carr B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effects of Ice Formations on Airplane Performance in Level Cruising Flight

Description: "A flight investigation in natural icing conditions was conducted by the NACA to determine the effect of ice accretion on airplane performance. The maximum loss in propeller efficiency encountered due to ice formation on the propeller blades was 19 percent. During 87 percent of the propeller icing encounters, losses of 10 percent or less were observed" (p. 1).
Date: May 1948
Creator: Preston, G. Merritt & Blackman, Calvin C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Icing Protection for a Turbojet Transport Airplane: Heating Requirements, Methods of Protection, and Performance Penalties

Description: "The problems associated with providing icing protection for the critical components of a typical turbojet transport airplane operating over a range of probable icing conditions are analyzed and discussed. Heating requirements for several thermal methods of protection are evaluated and the airplane performance penalties associated with providing this protection from various energy sources are assessed. The continuous heating requirements for icing protection and the associated airplane performa… more
Date: January 1953
Creator: Gelder, Thomas F.; Lewis, James P. & Koutz, Stanley L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Improvements in Heat Transfer for Anti-Icing of Gas-Heated Airfoils with Internal Fins and Partitions

Description: "The effect of modifying the gas passage of hollow metal airfoils by the addition of internal fins and partitions was experimentally investigated and comparisons were made among a basic unfinned airfoil section and two airfoil designs having metal fins attached at the leading edge of the internal gas passage. An analysis considering the effects of heat conduction in the airfoil metal was made to determine the internal modification effectiveness that may be obtained in gas-heated components, suc… more
Date: July 1950
Creator: Gray, Vernon H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Flight Investigation of the Thermal Performance of Air Heated Propeller

Description: Note presenting the thermal performance of an air-heated propeller, installed on a test airplane, as evaluated by observations of the ice-prevention properties of the propeller during flight in natural icing conditions and by the collection of thermal data on the propeller during flight in clear air and in clouds at temperatures above freezing. The results indicated that the air-heated-propeller installation tested would offer little or no protection to the leading-edge regions of the propeller… more
Date: April 1947
Creator: Darsow, John F. & Selna, James
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Icing and De-Icing of a Propeller with Internal Electric Blade Heaters

Description: "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 concent… more
Date: August 1948
Creator: Lewis, James P. & Stevens, Howard C., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

De-Icing Effectiveness of External Electric Heaters for Propeller Blades

Description: Note presenting an investigation in the icing research tunnel to determine the icing protection provided by external rubber-clad blade heaters at several icing, heating, and propeller operating conditions. Data are presented to show the effect of propeller speed, ambient-air temperature, liquid-water concentration, heating-power density, duration of heating, and total cycle times on the power requirements and de-icing performance of the blade heaters.
Date: February 1948
Creator: Lewis, James P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing 1: Unpartitioned Blades

Description: From Summary: "An investigation to determine the effectiveness of icing protection afforded by air-heating hollow steel unpartitioned propeller blades has been conducted In the NACA Cleveland icing research tunnel. The propeller used was a production model modified with blade shank and tip openings to permit internal passage of heated air. Blade-surface and heated-air temperatures were obtained and photographic observations of Ice formations were made with variations In icing intensity and heat… more
Date: May 1948
Creator: Mulholland, Donald R. & Perkins, Porter J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 2: 50% Impartitioned Blades

Description: From Summary: "The icing protection afforded an internal air-heated propeller blade by radial partitioning at 50-percent chord to confine the heated air to the forward half of the blade was determined in the NACA Cleveland icing research tunnel. A modified production-model hollow steel propeller, was used for the investigation. Temperatures of the blade surfaces for several heating rates were measured under various tunnel icing conditions. Photographic observations of ice formations on blade su… more
Date: May 1948
Creator: Perkins, Porter J. & Mulholland, Donald R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 3: 25% Partitioned Blades

Description: From Summary: "The icing protection obtained from an internally air-heated propeller blade partitioned to confine the heated air forward of 25-percent chord was investigated in the NACA Cleveland icing research tunnel. A production-model hollow steel propeller was modified with an Internal radial partition at 25-percent chord and with shank and tip openings to admit and exhaust the heated air. Temperatures were measured on the blade surfaces and in the heated-air system during tunnel icing cond… more
Date: May 1948
Creator: Mulholland, Donald R. & Perkins, Porter J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Method for Estimating Heat Requirements for Ice Prevention Gas Heated Hollow Propeller Blades

Description: Report presenting a method for determining the temperature and flow of heated gas necessary for ice prevention of hollow propeller blades in flight and icing conditions. A variety of conditions are taken into consideration and suggested simplifications and short methods are provided in order to not overcomplicate the design modifications.
Date: December 1947
Creator: Gray, V. H. & Campbell, R. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

An Investigation Utilizing an Electrical Analogue of Cyclic Deicing of a Hollow Steel Propeller with an External Blade Shoe

Description: "A study has been made of the heat requirement for the cyclic de-icing of hollow steel propellers fitted with external blade heating shoes. Solutions to the equations for the heat flow in cyclic heating of propellers were obtained, using an electrical analogy. The study showed how the energy requirement for propeller de-icing with existing blade shoes could be decreased, and illustrated the effect of blade-shoe design on the energy requirement. It was demonstrated, for example, that by increas… more
Date: December 1952
Creator: Neel, Carr B., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

On the Permeability of Porous Materials

Description: Note presenting an investigation of the effects on porous-material permeability characteristics of the absolute pressure level, choking of the flow, bending the material, and other factors. Experiments showed permeability characteristics to be appreciably affected by absolute pressure level, flow choking, and thickness of the material. Results regarding testing with wire cloth and sintered metal are provided.
Date: January 1956
Creator: Yates, E. Carson, Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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