Transonic Investigation of Aerodynamic Characteristics of a Swept-wing Fighter-airplane Model with Leading-edge Droop in Combination with Outboard Chord-extensions and Notches


Book Description

An investigation of the effects of several wing leading-edge modifications on the aerodynamic characteristics of a 45 degree swept-wing fighter-airplane model has been conducted in the Langley 16-foot transonic tunnel at low and high lifting conditions at Mach numbers from 0.85 to 1.03. The investigation included the determination of the effect on longitudinal stability and performance characteristics of wing leading-edge and chord-extension droops of 6 and 20 degrees, chord-extension overhangs of 0.075c and 0.15c (where c is the wing chord), leading-edge notches cut out at the inboard end of the 0.075c chord-extension to depths of 0.075c and 0.125c, and indentation of the model fuselage to conform partially to the supersonic area rule for a Mach number of 1.20. Lift, drag, and pitching-moment data were obtained for configurations with the tail on and off. Comparisons of data obtained from the present model with data from a configuration with leading-edge slats are included.







A Supersonic Area Rule and an Application to the Design of a Wing-body Combination with High Lift-drag Ratios


Book Description

Summary: As an extension of the transonic area rule, a concept for interrelating the wave drags of wing-body combinations at moderate supersonic speeds with axial developments of cross-sectional area has been derived. The wave drag of a combination at a given supersonic speed is related to a number of developments of cross-sectional areas as intersected by Mach planes. On the basis of this concept and other design procedures, a structurally feasible, swept-wing--indented-body combination has been designed to have relatively high maximum lift-drag ratios over a range of transonic and moderate supersonic Mach numbers. The wing of the combination has been designed to have reduced drag associated with lift and, when used with an indented body, to have low zero-lift wave drag. Experimental results have been obtained for this configuration at Mach numbers from 0.80 to 2.01. Maximum lift-drag ratios of approximately 14 and 9 were measured at Mach numbers of 1.15 and 1.41, respectively.




Reduction of Drag Due to Lift at Supersonic Speeds


Book Description

$EVERAL TOPICS RELATING TO THE REDUCTION OF DRAG DUE TO LIFT AT SUPERSONIC SPEEDS ARE DISCUSSED. The distribution of camber for optimial loading of diamond planform wings and some low drag geometries for rectangular wings are determined. It appears that substantial drag reduction, through the use of spanwise distribution of camber, may be achieved only for low reduced aspect ratios, M2-1 AR. The distribution of lift throughout volumes of prescribed shape is considered and some optimum distributions found for certain cases. It is shown that optimum spatial distributions of lift arc generally not unique. The possibility of using biplanes is explored and it is concluded that for non-interfering biplanes (wings acting as isolated monoplanes) there is an inherent structural advantage which is the result of a scale effect for geometrically similar structures The preacnt status of means for drag reduction is surveyed and the direction for further study indicated.