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Proposal for a propeller side-force factor

Description: Report discusses a proposal for propeller manufacturers to consider the side-force factor with the activity factor as a fundamental parameter for all blade designs and for the side-force factor to be included in all reports of powered models in wind tunnels. The proposal includes a method for calculating the side-force factor and how it can be used in propeller development. It is shown to be a good index of the relative effectiveness per blade of a yawed propeller in developing side force.
Date: December 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Time-dependent downwash at the tail and the pitching moment due to normal acceleration at supersonic speeds

Description: Report presenting an analysis of the time-dependent downwash behind a wing in a supersonic stream when the angle of attack varies linearly with time. The result is applied to the calculation of the contribution of the horizontal tail to the pitching moment and lift due to normal acceleration of the airplane. Results regarding downwash charts and some limitations on the results are provided.
Date: February 1950
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

A transonic propeller of triangular plan form

Description: Report presenting a proposal for the isosceles triangle twisted into a screw surface about its axis as a propeller for transonic flight speeds. The purpose is to attain the drag reduction associated with a large sweepback in a structurally practicable configuration.
Date: May 1947
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Attainment of a straight-line trajectory for a preset guided missile with special reference to effect of wind or target motion

Description: Report discusses the results of a study "of the requirements for the attainment of a straight-line trajectory for a preset guided missile in the presence of wind or target motion" (from Summary). Information about the straight-line trajectory, position of the launching airplane, straight-line collision course, and arrangement of the autopilot in the missile is provided. Recommendations are also made about the creation of a bombsight mounting for the pilot of the launching airplane in order to attain the desired straight-line collision course.
Date: August 1945
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Field of Flow About a Jet and Effect of Jets on Stability of Jet-Propelled Airplanes

Description: A theoretical investigation was conducted on jet-induced flow deviation. Analysis is given of flow inclination induced outside cold and hot jets and jet deflection caused by angle of attack. Applications to computation of effects of jet on longitudinal stability and trim are explained. Effect of jet temperature on flow inclination was found small when thrust coefficient is used as criterion for similitude. The average jet-induced downwash over tail plane was obtained geometrically.
Date: April 1946
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Formulas for propellers in yaw and charts of the side-force derivative

Description: General formulas are given for propellers for the rate of change of side-force coefficient with angle of yaw and for the rate of change of pitching-moment coefficient with angle of yaw. Charts of the side-force derivative are given for two propellers of different plan form. The charts cover solidities of two to six blades and single and dual rotation. The blade angle ranges from 15 degrees or 20 degrees to 60 degrees.
Date: April 7, 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Formulas for propellers in yaw and charts of the side-force derivative

Description: Report presenting formulas for propellers for the rate of change of side-force coefficient with angle of yaw and for the rate of change of pitching-moment coefficient with angle of yaw. Charts of side-force derivatives are given for two propellers of different plan forms.
Date: May 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Propellers in yaw

Description: It was realized as early as 1909 that a propeller in yaw develops a side force like that of a fin. In 1917, R. G. Harris expressed this force in terms of the torque coefficient for the unyawed propeller. Of several attempts to express the side force directly in terms of the shape of the blades, however, none has been completely satisfactory. An analysis that incorporates induction effects not adequately covered in previous work and that gives good agreement with experiment over a wide range of operating conditions is presented. The present analysis shows that the fin analogy may be extended to the form of the side-force expression and that the effective fin area may be taken as the projected side area of the propeller.
Date: October 11, 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Notes on the propeller and slipstream in relation to stability

Description: Report presenting charts and formulas in convenient form for use in the computation of the effects of propellers on stability. Formulas are given for the contributions of the direct propeller forces to the airplane pitching moment, yawing moment, and shift in neutral point due to power.
Date: October 1944
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Propellers in yaw

Description: Report presenting the propeller forces due to an angular velocity of pitch, which are analyzed and shown to be very small for the pitching velocities that may actually be realized in maneuvers, with the exception of the spin. A dual-rotating propeller in yaw was found to develop up to one-third more side force than a single-rotating propeller.
Date: December 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

The stability derivatives of low-aspect-ratio triangular wings at subsonic and supersonic speeds

Description: Report presenting low-aspect-ratio wings with triangular plan form, which are treated on the assumption that the flow potentials in planes at right angles to the long axis of the airfoils are similar to the corresponding two-dimensional potentials. Pressure distributions caused by downward acceleration, pitching, rolling, sideslipping, and yawing are obtained for wings with and without dihedral.
Date: September 1947
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

A Remote Indicating Hinge-Moment Balance, Special Report

Description: This report describes an electrical hinge-moment balance for use with wind-tunnel models of aircraft. A brief description of the principle of operation and operating experience with the balance is given in part I. Part II gives constructional details and part III gives theoretical considerations. Extensive constructional information is given to enable the reproduction of the equipment.
Date: August 1941
Creator: Stoller, Morton J. & Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Interaction between a supersonic stream and a parallel subsonic stream bounded by fluid at rest

Description: "The complex problem of the interaction between shock waves and boundary layers in supersonic flow is not yet clearly understood, despite a number of theoretical studies. Among these, the analysis of Tsein and Finston is singled out here for further examination. In the Tsien-Finston model the boundary layer is simulated by a uniform subsonic stream of finite width bounded on one side by a solid wall and on the other side by the interface with a uniform supersonic stream of semi-infinite extent" (p. 2).
Date: December 1952
Creator: Ribner, Herbert S. & Arnoff, E. Leonard
Partner: UNT Libraries Government Documents Department

Stability derivatives of triangular wings at supersonic speeds

Description: "The analysis of the stability derivatives of low-aspect-ratio triangular wings at subsonic and supersonic speeds, given in NACA TN no. 1423, is extended to apply to triangular wings having large vertex angles and traveling at supersonic speeds. The lift, rolling moment due to sideslip, and damping in roll and pitch for this more general case have been treated elsewhere on the basis of the theory of small disturbances. The surface potentials for angle of attack and rolling taken therefrom are used to obtain the several side-force and yawing-moment derivatives that depend on leading-edge suction, and a tentative value for the rolling moment due to yawing" (p. 317).
Date: November 6, 1947
Creator: Ribner, Herbert S. & Malvestuto, Frank S., Jr.
Partner: UNT Libraries Government Documents Department

Theoretical lift and damping in roll at supersonic speeds of thin sweptback tapered wings with streamwise tips, subsonic leading edges, and supersonic trailing edges

Description: "On the basis of linearized supersonic-flow theory, generalized equations were derived and calculations made for the lift and damping in roll of a limited series of thin sweptback tapered wings. Results are applicable to wings with streamwise tips and for a range of supersonic speeds for which the wing is wholly contained between the Mach cones springing from the wing apex and from the trailing edge of the root section. A further limitation is that the tip Mach lines may not intersect on the wing" (p. 395).
Date: February 15, 1949
Creator: Malvestuto, Frank S., Jr.; Margolis, Kenneth & Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department