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Investigation of Aerodynamic and Icing Characteristics of a Flush Alternate Inlet Induction System Air Scoop

Description: An investigation has been made in the NACA Lewis icing research tunnel to determine the aerodynamic and icing characteristics of a full-scale induction-system air-scoop assembly incorporating a flush alternate inlet. The flush inlet was located immediately downstream of the offset ram inlet and included a 180 deg reversal and a 90 deg elbow in the ducting between inlet and carburetor top deck. The model also had a preheat-air inlet. The investigation was made over a range of mass-air- flow ratios of 0 to 0.8, angles of attack of 0 and 4 deg airspeeds of 150 to 270 miles per hour, air temperatures of 0 and 25 F various liquid-water contents, and droplet sizes. The ram inlet gave good pressure recovery in both clear air and icing but rapid blockage of the top-deck screen occurred during icing. The flush alternate inlet had poor pressure recovery in both clear air and icing. The greatest decreases in the alternate-inlet pressure recovery were obtained at icing conditions of low air temperature and high liquid-water content. No serious screen icing was observed with the alternate inlet. Pressure and temperature distributions on the carburetor top deck were determined using the preheat-air supply with the preheat- and alternate-inlet doors in various positions. No screen icing occurred when the preheat-air system was operated in combination with alternate-inlet air flow.
Date: July 24, 1953
Creator: Lewis, James P.
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

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 investiation 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 icingwas indicated by the forward movement of transition from laminar to turbulent heat transfer. An analysis of the flight results showed the convective heat transfer in icing to be considerably different from that measured in clear air and. only slightly different from that obtained in the icing-research tunnel during simulated icing.
Date: September 1, 1951
Creator: Gelder, Thomas F. & Lewis, James P.
Partner: UNT Libraries Government Documents Department

Preliminary Investigation of Cyclic De-Icing of an Airfoil Using an External Electric Heater

Description: "An investigation was conducted in the NACA Lewis icing research tunnel to determine the characteristics and requirements of cyclic deicing of a 65,2-216 airfoil by use of an external electric heater. The present investigation was limited to an airspeed of 175 miles per hour. Data are presented to show the effects of variations in heat-on and heat-off periods, ambient air temperature, liquid-water content, angle of attack, and. heating distribution on the requirements for cyclic deicing" (p. 1).
Date: February 4, 1952
Creator: Lewis, James P. & Bowden, Dean T.
Partner: UNT Libraries Government Documents Department

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 surface temperature and a uniform input heater density distribution were used."
Date: November 1956
Creator: Lewis, James P. & Ruggeri, Robert S.
Partner: UNT Libraries Government Documents Department

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 power density were used."
Date: October 1957
Creator: Ruggeri, Robert S. & Lewis, James P.
Partner: UNT Libraries Government Documents Department

Experimental Droplet Impingement on Four Bodies of Revolution

Description: An experiment was conducted to obtain the rate and area of cloud droplet impingement on four bodies of revolution was conducted in the icing tunnel with a dye-tracer technique. The study included several forebody shapes of different fineness ratios over a range of angles of attack and rotational speeds. Results regarding velocity distribution, local impingement characteristics, and correlation of impingement characteristics are provided.
Date: December 1957
Creator: Lewis, James P. & Ruggeri, Robert S.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Radome Icing and Icing Protection

Description: Memorandum presenting an investigation conducted in the icing research tunnel to determine the icing characteristics, the effects of icing on radar operation, and the protection requirements for two radome configurations. The radomes were for the F-89 airplane and were investigated at airspeeds up to 290 miles per hour, air total temperatures from -15 to 20 degrees Fahrenheit, water contents up to 1.0 gram per cubic meter, and angles of attack of 0 and 4 degrees.
Date: January 20, 1953
Creator: Lewis, James P. & Blade, Robert J.
Partner: UNT Libraries Government Documents Department

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 performance penalties for the turbojet transport are considerably increased over those associated with lower-speed aircraft. Experimental results show that the heating requirements can be substantially reduced by the deve1opment of a satisfactory cyclic deicing system. The problem of providing protection can be minimized by employing a proper energy source since the airplane performance penalties vary considerably with the source of energy employed. The optimum icing protection system for the turbojet transport or for any other particular aircraft cannot be generally specified; the choice of the optimum system is dependent upon the specific characteristics of the airplane and engine, the flight plan, the probable icing conditions, and the performance requirements of the aircraft.
Date: January 1953
Creator: Gelder, Thomas F.; Lewis, James P. & Koutz, Stanley L.
Partner: UNT Libraries Government Documents Department

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 concentration, and the duration of the heat-on and cycle times on the power requirements and de-Icing performance of the blade heaters. The extent of ice-covered area on the blades for various icing ax4 operating conditions has been determined. The largest iced area was obtained at the higher ambient-air temperatures and at low propeller speed. The ohord.wise extent of Icing In practically every case was greater than that covered by blade heaters. Adequate de-icing in the heated area with continuous application of heat was obtained with the power available but a maximum power, input of 1250 watts per blade was insufficient for cyclic de-Icing for the range of conditions investigated. Blade-surface temperature rates of rise of 0.2 to 0.7 F per second were obtained and the minimum cooling period for cyclic de-icing was found to be approximately 2-1/2 times the heating period.
Date: August 1948
Creator: Lewis, James P. & Stevens, Howard C., Jr.
Partner: UNT Libraries Government Documents Department

Icing protection for a turbojet transport airplane : heating requirements methods of protection, and performance penalties

Description: Report analyzing and discussing 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. Heating requirements for several thermal methods of protection are evaluated and the airplane performance penalties associated with providing protection from various energy sources are provided.
Date: January 1953
Creator: Gelder, Thomas F.; Lewis, James P. & Koutz, Stanley L.
Partner: UNT Libraries Government Documents Department