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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
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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
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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
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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
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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
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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
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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
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
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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
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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
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
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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
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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
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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
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Perforated Sheets as a Porous Material for Distributed Suction and Injection

Description: Note presenting measurements made of the resistance to air flow of a series of perforated metal sheets with open areas ranging from less than 1 percent up to 41 percent. The results showed that the permeability of a perforated sheet is governed principally by its open-area ratio. The number of holes per square inch, the sheet thickness, and the shape of the individual holes had little or no effect on permeability.
Date: April 1956
Creator: Dannenberg, Robert E.; Gambucci, Bruno J. & Weiberg, James A.
Item Type: Refine your search to only Report
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Experimental Study of the Effects of Finite Surface Disturbances and Angle of Attack on the Laminar Boundary Layer of an NACA 64A010 Airfoil With Area Suction

Description: Note presenting a low-turbulence wind-tunnel investigation of an NACA 64A010 airfoil section with continuous suction through its porous surfaces to determine its ability to maintain extensive laminar flow behind finite surface disturbances and at angles of attack other than 0 degrees. Generally, application of area suction permitted only a small increase in the size of a finite disturbance required to cause premature boundary-layer transition as compared with the nonsuction airfoil.
Date: October 1952
Creator: Schwartzberg, Milton A. & Braslow, Albert L.
Item Type: Refine your search to only Report
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Effects of Extreme Surface Cooling on Boundary-Layer Transition

Description: Note presenting an investigation to determine the combined effects of surface cooling, pressure gradients, nose blunting, and surface finish on boundary-layer transition. Data were obtained for various body shapes at a Mach number of 3.12 and Reynolds numbers per foot as high as 15 x 10(exp 6). Results regarding the effect of extreme cooling, effect of pressure gradient, effect of blunting, effect of surface roughness, and roughness as cause of transition reversal are provided.
Date: October 1957
Creator: Jack, John R.; Wisniewski, Richard J. & Diaconis, N. S.
Item Type: Refine your search to only Report
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Simplified Method for Determination of Critical Height of Distributed Roughness Particles for Boundary-Layer Transition at Mach Numbers From 0 to 5

Description: Note presenting a simplified method for determination of the critical height of three-dimensional roughness particles required to promote premature transition of a laminar boundary layer on models of airplanes or airplane components in a wind tunnel with zero heat transfer. The method has been applied to various types of configurations in several wind-tunnel investigations.
Date: September 1958
Creator: Braslow, Albert L. & Knox, Eugene C.
Item Type: Refine your search to only Report
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Investigation of Suction-Slot Shapes for Controlling a Turbulent Boundary Layer

Description: Note presenting tests of three types of boundary-layer-control suction slots in a two-dimensional diffuser to investigate design criterions and to evaluate the practical minimum total-pressure losses. Testing occurred at a velocity of about 100 feet per second with a boundary layer with a displacement thickness of 0.85 inch and a shape parameter of about 1.8.
Date: June 1947
Creator: Pierpont, P. Kenneth
Item Type: Refine your search to only Report
open access

Effect of Type of Porous Surface and Suction Velocity Distribution on the Characteristics of a 10.5 Percent-Thick Airfoil With Area Suction

Description: Note presenting an investigation at low speed of the two-dimensional characteristics of a 10.51-percent-thick symmetric airfoil with area suction for boundary-layer control near the leading edge. The lift and suction-flow characteristics were determined with different porous surfaces consisting of perforated plates and sintered steel for various suction velocity distributions obtained by varying the permeability arrangement.
Date: December 1953
Creator: Dannenberg, Robert E. & Weiberg, James A.
Item Type: Refine your search to only Report
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The Resistance to Air Flow of Porous Materials Suitable for Boundary-Layer-Control Applications Using Area Suction

Description: "Measurements were made of the resistance to air flow of commercially available porous materials. Three general types of porous media were tested - granular (sintered materials), fibrous (felt cloths and filter papers), and perforated. The flow-resistance characteristics of the porous materials tested are presented in a form intended to assist in the selection of materials for applications to boundary-layer control using area suction" (p. 1).
Date: January 1954
Creator: Dannenberg, Robert E.; Weiberg, James A. & Gambucci, Bruno J.
Item Type: Refine your search to only Report
open access

A flight investigation of the practical problems associated with porous-leading-edge suction

Description: From Summary: "A flight investigation has been made of the practical problems associated with the use of porous-leading-edge suction. The wing leading edge of the test airplane was porous over approximately 83 percent of the span and the first 8 percent of the chord on the upper surface. Various other extents of suction area within these limits were also tested."
Date: February 1954
Creator: Hunter, Paul A. & Johnson, Harold I.
Item Type: Refine your search to only Report
open access

A Fibrous-Glass Compact as a Permeable Material for Boundary-Layer-Control Applications Using Area Suction

Description: "Measurements were made of the resistance of fibrous-glass compacts to normal air flow. The flow resistance was related to the thickness and density. As a porous material for boundary-layer-control applications using area suction, the fibrous-glass compact could be made to any desired thickness and permeability and sandwiched between perforated rigid surfaces" (p. 1).
Date: January 1955
Creator: Dannenberg, Robert E.; Weiberg, James A. & Gambucci, Bruno J.
Item Type: Refine your search to only Report
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