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Impingement of water droplets on wedges and double-wedge airfoils at supersonic speeds

Description: An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves. The results presented include the following conditions: droplet diameters from 2 to 100 microns, pressure altitudes from sea level to 30,000 feet, free-stream static temperatures from 420 degrees r, free stream Mach numbers from 1.1 to 2.0, semiapex angles for the wedge from 1.14 degrees to 7.97 degrees, thickness-to-chord ratios for the diamond airfoil from 0.02 to 0.14, chord lengths from 1 to 20 feet, and angles of attack from zero to the inverse tangent of the airfoil thickness-to-chord ratio.
Date: January 1, 1954
Creator: Serafini, John S
Partner: UNT Libraries Government Documents Department

Impingement of water droplets on wedges and diamond airfoils at supersonic speeds

Description: An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves. The results presented include the following conditions: droplet diameters from 2 to 100 microns, pressure altitudes from sea level to 30,000 feet, free-stream static temperatures from 420 degrees to 460 degrees R. Also, free-stream Mach numbers from 1.1 to 2.0, semi-apex angles for the wedge from 1.14 degrees to 7.97 degrees, thickness-to-chord ratios for the diamond airfoil from 0.02 to 0.14, chord lengths from 1 to 20 feet, and angles of attack from zero to the inverse tangent of the airfoil thickness-to-chord ratio.
Date: July 1, 1953
Creator: Serafini, John S
Partner: UNT Libraries Government Documents Department

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 45,000 feet.
Date: March 1953
Creator: Callaghan, Edmund E. & Serafini, John S.
Partner: UNT Libraries Government Documents Department

Analytical investigation of icing limit for diamond-shaped airfoil in transonic and supersonic flow

Description: From Introduction: "The results presented herein were calculated for a symmetrical diamond airfoil at zero angle of attack for a range of airfoil-thickness ratios from 0.02 to 0.10, pressure altitude from sea level to 45,000 feet, and free-stream static temperatures to -.40^o F."
Date: January 1953
Creator: Callaghan, Edmund E & Serafini, John S
Partner: UNT Libraries Government Documents Department

Analytical Investigation of Icing Limit for Diamond-Shaped Airfoil in Transonic and Supersonic Flow

Description: Calculations have been made for the icing limit of a diamond airfoil at zero angle of attack in terms of the stream Mach number, stream temperature, and pressure altitude. The icing limit is defined as a wetted-surface temperature of 320 F and is related to the stream conditions by the method of Hardy. The results show that the point most likely to ice on the airfoil lies immediately behind the shoulder and is subject to possible icing at Mach numbers as high as 1.4.
Date: January 1953
Creator: Callaghan, Edmund E. & Serafini, John S.
Partner: UNT Libraries Government Documents Department

Exploratory investigation of static- and base-pressure increases resulting from combustion of aluminum borohydride adjacent to body of revolution in supersonic wing tunnel

Description: Report presenting pressure distribution associated with the stable combustion of aluminum borohydride about a body of revolution in a wind tunnel at Mach number 2.47. Pressure increases on the cylindrical and base surfaces of the model were measured. Results regarding the burning and associated flow phenomena, axial and meridional static-pressure data obtained during combustion, and base-pressure data during combustion are provided.
Date: October 2, 1957
Creator: Serafini, John S.; Dorsch, Robert G. & Fletcher, Edward A.
Partner: UNT Libraries Government Documents Department

Pressure distribution and aerodynamic coefficients associated with heat addition to supersonic air stream adjacent to two-dimensional supersonic wing

Description: The modifications in the pressure distributions and the aerodynamic coefficients associated with additions of heat to the two-dimensional supersonic in viscid flow field adjacetnt to the lower surface of of a 5-percent-thickness symmetrical circular-arc wing are presented in this report. The pressure distributions are obtained by the use of graphical method which gives the two-dimensional supersonic inviscid flow field obtained with moderate heat addition. The variation is given of the lift-drag ratio and of the aerodynamic coefficients of lift, drag, and moment with free stream Mach number, angle of attack, and parameters defining extent and amount of heat addition. The six graphical solutions used in this study included Mach numbers of 3.0 and 5.0 and angles of attack of 0 degrees and 2 degrees.
Date: February 14, 1952
Creator: Pinkel, I. Irving; Serafini, John S. & Gregg, John L.
Partner: UNT Libraries Government Documents Department

A preliminary investigation of static-pressure changes associated with combustion of aluminum borohydride in a supersonic wind tunnel

Description: Report presenting static-pressure changes resulting from steady combustion of aluminum borohydride in a supersonic wind tunnel. Static pressures were measured along the top wall of a tunnel adjacent to the flame that filled the upper portion of the test section. Results regarding the static-pressure increases, effect of change in fuel-injection rate, and effect of tunnel boundary layer on the character of the heat-addition region are provided.
Date: August 18, 1955
Creator: Dorsch, Robert G.; Serafini, John S. & Fletcher, Edward A.
Partner: UNT Libraries Government Documents Department

Exploratory investigation of aerodynamic effects of external combustion of aluminum borohydride in airstream adjacent to flat plate in Mach 2.46 tunnel

Description: Report presenting pressure distributions associated with stable combustion of aluminum borohydride in the supersonic stream adjacent to a short, 13-inch chord, and an extended, 25-inch chord, flat-plate model. High-speed direct and schileren motion pictures of the flame and associated shock waves were taken. Results regarding the description of the combustion and associated stream disturbances, static-pressure change at model reference surface caused by combustion, lift forces resulting from combustion, base pressure change caused by combustion, stream-parameter measurements during combustion, and surface temperature changes during combustion are provided.
Date: July 29, 1957
Creator: Dorsch, Robert G.; Serafini, John S. & Fletcher, Edward A.
Partner: UNT Libraries Government Documents Department

Impingement of Water Droplets on an NACA 65(sub 1) -212 Airfoil at an Angle of Attack of 4 Deg

Description: The trajectories of droplets in the air flowing past an NACA 651-212 airfoil at an angle of attack of 40 were determined. The collection efficiency, the area of droplet impingement, and the rate of droplet impingement were calculated from the trajectories and are presented herein.
Date: September 10, 1952
Creator: Brun, Rinaldo J.; Serafini, John S. & Moshos, George J.
Partner: UNT Libraries Government Documents Department