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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
Wind-Tunnel Investigation of the Lift Characteristics of an NACA 27-212 Airfoil Equipped with Two Types of Flap, Special Report

Wind-Tunnel Investigation of the Lift Characteristics of an NACA 27-212 Airfoil Equipped with Two Types of Flap, Special Report

Date: September 1, 1940
Creator: Swanson, Robert S.
Description: An investigation has been made in the NACA 7- by 10-foot wind tunnel of a large chord NACA 27-212 airfoil with a 20% chord split flap and with two arrangements of a 25.66% chord slotted flap to determine the section lift characteristics as affected by flap deflection for the split flap and as affected by flap deflection, flap position, and slot shape for the slotted flap. For the two arrangements of the slotted flap, the flap positions for maximum section lift are given. Comparable data on the NACA 23012 airfoil equipped with similar flaps are also given. On the basis of maximum section lift coefficient, the slotted flap with an easy slot entry was slightly better than either the split flap or the slotted flap with a sharp slot entry. With both types of flap the decrease in the angle of attack, for maximum section lift coefficient, with flap deflection is large for the NACA 27-212 airfoil as compared with the NACA 23012 airfoil. Also with both flaps, the maximum section lift coefficient obtained with flaps is much lower for the NACA 27-212 airfoil than for the NACA 23012 airfoil.
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Investigation of the Low-Speed Characteristics of a 1/8-Scale Model of the Republic XP-91 Airplane with a Vee and a Conventional Tail

Wind-Tunnel Investigation of the Low-Speed Characteristics of a 1/8-Scale Model of the Republic XP-91 Airplane with a Vee and a Conventional Tail

Date: December 15, 1947
Creator: Weiberg, James A.
Description: Low-speed wind-tunnel tests of a l/8 scale model of the Republic XP-91 airplane were made to determine its low-speed characteristics and the relative merits of a vee and a conventional tail on the model. The results of the tests showed that for the same amount of longitudinal and directional stability the conventional tail gave less roll due to sideslip than did the vee tail. The directional stability of the model was considered inadequate for both the vee and conventional tails; however, increasing the area and aspect ratio of the conventional vertical tail provided adequate directional stability. It was possible with negative wing dihedral and open main landing gear doors to reduce the excessive roll due to sideslip for the landing configuration (flaps and gear down) to a more reasonable value commensurate with the aileron power. The use of variable wing incidence to adjust the longitudinal balance was sufficiently effective to reduce the predicted up-elevator required for landing by approximately 5 deg.
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel investigation of the low-speed stability and control characteristics of a model with a sweptback vee tail and a sweptback wing

Wind-tunnel investigation of the low-speed stability and control characteristics of a model with a sweptback vee tail and a sweptback wing

Date: May 25, 1948
Creator: Polhamus, Edward C
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Investigation of the Low-Speed Static Stability and Control Characteristics of a Model of Bell MX-776

Wind-Tunnel Investigation of the Low-Speed Static Stability and Control Characteristics of a Model of Bell MX-776

Date: July 6, 1949
Creator: Queijo, M. J.
Description: An investigation has been made in the Langley stability tunnel to determine the low-speed static stability and control characteristics of a model of the Bell MX-776. The results of the investigation indicated that the basic model configuration was longitudinally stable in the angle-of-attack range from about -16 deg. to 16 deg. but that the stability was a minimum near O deg angle of attack. The data indicated an aerodynamic-center position about 0.64 body diameters behind the center of gravity at low angles of attack. Reduction in the size of the front horizontal fins increased the longitudinal stability. With 20 percent of the span of the normal front horizontal fins cut off the aerodynamic center was about 1.04 body diameters behind the center of gravity, and with front horizontal fins having the same area as the front vertical fins, the aerodynamic center was 2.26 body diameters behind the center of gravity (at low angles of attack).
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Investigation of the Low-Speed Static Stability and Control Characteristics of a Model of the Bell MX-776 (RASCAL) in Combined Angle of Attack and Sideslip

Wind-Tunnel Investigation of the Low-Speed Static Stability and Control Characteristics of a Model of the Bell MX-776 (RASCAL) in Combined Angle of Attack and Sideslip

Date: January 1, 1949
Creator: Letko, William
Description: An investigation has been made in the Langley stability tunnel to determine the low-speed static stability and control characteristics of a model of the Bell MX-776. The results show the model to be longitudinally unstable in the angle-of-attack range around zero angle of attack and to become stable at moderate angles of attack. The results of the present investigation agree reasonably well with results obtained in other facilities at low speed. The present pitching-moment results at low Mach numbers also agree reasonably well with unpublished results of tests of the model at supersonic Mach numbers (up to Mach number 1.86). Unpublished results at moderate and high subsonic speeds, however, indicate considerably greater instability at low angles of attack than is indicated by low-speed results. The results of the present tests also showed that the pitching-moment coefficients for angles of attack up to 12deg remained fairly constant with sideslip angle up to 12deg. The elevators tested produced relatively large pitching moments at zero angle of attack but, as the angle of attack was increased, the elevator effectiveness decreased. The rate of decrease of elevator effectiveness with angle of attack was less for 8deg than for 20deg elevator deflection. Therefore although 8deg ...
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel investigation of the NACA 654-421 airfoil section with a double slotted flap and boundary layer control by suction

Wind-tunnel investigation of the NACA 654-421 airfoil section with a double slotted flap and boundary layer control by suction

Date: July 1, 1947
Creator: Quinn, John H
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Investigation of the Opening Characteristics, Drag, and Stability of Several Hemispherical Parachutes

Wind-Tunnel Investigation of the Opening Characteristics, Drag, and Stability of Several Hemispherical Parachutes

Date: October 7, 1948
Creator: Scher, Stanley E.
Description: An investigation has been conducted to determine the opening characteristics of several hemispherical parachutes and to study the influence of the parachute design variables on these opening characteristics. The effects of design variables on the drag and stability characteristics of the parachutes were also evaluated. The tests were made in the Langley 20-foot free-spinning tunnel and in the Langley 300 MPH 7 by 10-foot tunnel.
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel investigation of the opening characteristics, drag, and stability of several hemispherical parachutes

Wind-tunnel investigation of the opening characteristics, drag, and stability of several hemispherical parachutes

Date: April 1, 1949
Creator: Scher, Stanley H
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel investigation of the spinning characteristics of a model of a twin-tail low-wing personal-owner-type airplane with linked and unlinked rudder and aileron controls

Wind-tunnel investigation of the spinning characteristics of a model of a twin-tail low-wing personal-owner-type airplane with linked and unlinked rudder and aileron controls

Date: January 1, 1949
Creator: Klinar, Walter J
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel investigation of the stability and control characteristics of a complete model equipped with a vee tail

Wind-tunnel investigation of the stability and control characteristics of a complete model equipped with a vee tail

Date: November 1, 1947
Creator: Polhamus, Edward C
Description: None
Contributing Partner: UNT Libraries Government Documents Department