Texas A&M researchers use aeroprobes to study the wakes of aircraft models

The Tilt-Body is a new kind of airplane, distinct from fixed wings and from rotary wings. It is not a "forced marriage" of the two, like other thrust-vectoring aircraft. It is neither fixed wing nor rotary wing nor any combination of the two. The Freewing™ Tilt-Body is really two innovations in one. The wing is placed on bearings so that it is completely free to rotate in pitch. (Imagine a weathervane turned horizontally.) The fuselage itself is a lifting body, so the result is a left/right wing pair conjoined by a cross spar passing through the lifting body. Both the left/right wing pair and the central lifting body are free to rotate about the spanwise shaft, free with regard to the relative wind and free with regard to each other.

A scaled-down model of the Freewing™ Tilt-Body was built and tested in the 3'x4' wind tunnel of the Aerospace Engineering Department of Texas A&M. Measurements were taken along a plane normal to the freestream, downstream of the fuselage, with a multi-hole probe.

Contours of the axial velocity component on the plane along the tail.

Multi-hole probe measurements were also taken over a slender delta wing, at an angle of attack, in the 6'x6' Wind Tunnel at Virginia Tech. The measurements were taken along a plane over the wing; the plane was normal to the freestream direction. The purpose was to capture the behavior of the leading edge vortex developing on the leeward side of the wing. The figure shows the velocity distribution along this plane, as viewed from downstream, i.e. on the port-side half of the wing. The in-plane velocity components are represented as arrows.

These leading edge vortices are responsible for providing the lift. A delta-wing application can be seen in the retired Concord. Later on, a fuselage was added and the model was tested again, although at a different facility.

Axial velocity contours over the model. Both leading edge vortices can be detected, because the flow in this reason has magnitudes even larger than the free stream.