Vortex-lift roll-control device

A wing is described for aircraft of cropped, arrow-type planform with thin leading and side edges. The wing has a pivotable tip to alter the crop angle of the wing during flight. Increasing the crop angle causes the wing side edge to become a trailing edge which reduces the strength of the side edge vortex flow. Decreasing the crop angle causes opposite results, in particular the side edge is now a leading edge and can generate a leading edge vortex flow. The wing constitutes a roll control device for aircraft of the stated design particularly effective at higher angles of attack

Modified Multhopp lifting surface loading program

Computer program determines the longitudinal subsonic aerodynamic characteristics of composite wings. The program uses the basic theoretical method of Multhopp in predicting the loading data

Modified Multhopp mean camber computer program

Computer program which determines the mean camber surface required to support a given set of loadings on a composite wing in subsonic compressible flow has been developed

Minimum trim drag design for interfering lifting surfaces using vortex-lattice methodology

A new method has been developed by which the mean camber surface can be determined for trimmed noncoplanar planforms with minimum vortex drag under subsonic conditions. The method uses a vortex lattice and overcomes previous difficulties with chord loading specification; it uses a Trefftz plane analysis to determine the optimum span loading for minimum drag, then solves for the mean camber surface of the wing which will provide the required loading. Pitching-moment or root-bending-moment constraints can be employed as well at the design lift coefficient. Sensitivity studies of vortex-lattice arrangement have been made with this method and are presented. Comparisons with other theories show generally good agreement. The versatility of the method is demonstrated by applying it to (1) isolated wings, (2) wing-canard configurations, (3) a tandem wing, and (4) a wing-winglet configuration

In-flight and wind tunnel leading-edge vortex study on the F-106B airplane

The vapor screen technique was successfully applied to an F-106B fighter aircraft during subsonic and transonic maneuvers. This system has allowed the viewing of multiple vortex systems on the wing upper surface at angles of attack less than 19 deg. In addition, similarities as well as differences were determined to exist between the vortex systems for a full scale semispan model and the flight vehicle at 20 deg incidence. Furthermore, variations in Reynolds number and Mach number were identified as to how they affect vortex system details at flight conditions

Longitudinal aerodynamic characteristics of 45 deg swept wings at Mach approximately 0

Wind tunnel tests were conducted in the Langley 7 x 10 foot wind tunnel at Mach numbers less than 0.20 and at Reynolds numbers less than 3.74 million. The effect of the aft area on the 45 deg swept wing longitudinal aerodynamic characteristics at low subsonic speeds and at an angle of attack range from approximately -2 deg to 28 deg was studied. The data are presented without analysis

Some recent applications of the suction analogy to vortex-lift estimates

An extension of the suction analogy for the estimation of vortex lift along the side edge of wings is reviewed along with the concept of an augmented vortex lift to account for the effect of the leading-edge vortex passing downstream over an aft part of the model. Applications of these extensions have resulted in an improved estimating capability for a wide range of isolated sharp-edge planforms and also for multiple lifting surfaces. Hence, the suction analogy concept can now have wider applicability at both subsonic and supersonic speeds, especially in the preliminary design cycle

Computer program calculates wing aerodynamic characteristics for fixed wings with dihedral and variable-sweep wings at subsonic speeds

Vortex lattice is used to describe the lifting surface of an arbitrary wing planform in steady potential subsonic compressible flow in computer program which calculates wing aerodynamic characteristics. Estimates of flow field characteristics in the vicinity of a lifting wing can also be programmed

On the logarithmic-singularity correction in the kernel function method of subsonic lifting-surface theory

A logarithmic-singularity correction factor is derived for use in kernel function methods associated with Multhopp's subsonic lifting-surface theory. Because of the form of the factor, a relation was formulated between the numbers of chordwise and spanwise control points needed for good accuracy. This formulation is developed and discussed. Numerical results are given to show the improvement of the computation with the new correction factor

Production version of the extended NASA-Langley Vortex Lattice FORTRAN computer program. Volume 1: User's guide

The latest production version, MARK IV, of the NASA-Langley vortex lattice computer program is summarized. All viable subcritical aerodynamic features of previous versions were retained. This version extends the previously documented program capabilities to four planforms, 400 panels, and enables the user to obtain vortex-flow aerodynamics on cambered planforms, flowfield properties off the configuration in attached flow, and planform longitudinal load distributions