HYPERSONIC FLEXWINGS AS ULTRALIGHT WAVERIDER VEHICLES

A CONCEPTUAL STUDY

BY

GORDON J. ROSS

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NB - Green numbers within brackets refer to references. Introduction Part Three The mission designer would have a much larger choice of options for a given manoeuvre or descent. The hollow shell of the vehicle allow greater scope in the choice of payloads and their shape and size. More volume can be "created" within the aircraft, simply by altering the angle between the top centreline strut and the floor pan. It is also possible to alter the frontal area of the aircraft in flight, to produce more drag, should this be required for atmosphere capture, or emergency descent from orbit. With the weight of the Waverider reduced to a fraction of its conventional counterpart's, the theoretical performance and speed range would be dramatically enhanced. It is also possible to incorporate some form of weight shift facility, for pitch and roll, even if it were only to trim the vehicle for level flight. The benefits of having what is effectively a "Microlight" Waverider are numerous, but the possibility exists to improve the design still further. In Fig.2 a four cavity Waverider Flexwing is shown. This device is intended to function purely as an Aero-Gravity Assist vehicle. As can be seen from the drawings, the payload is suspended from a harness within the umbrella-shaped craft. The four leading edges may be extended or retracted to produce attached shocks during atmosphere encounters. By varying the configurations lift may be generated perpendicular to the long axis of the aircraft. this means that lift may be produced in the positive, negative, right or left direction, or indeed, any combination of these. Simply by altering the angles of any of the four struts, the Flexwing can turn, climb or dive. It may also slow down rapidly by using a full deployment of all four struts, or if necessary, retract all four simultaneously to fly back out of an atmosphere, if it still has the velocity to escape. To construct a vehicle of this type will require exotic materials, but, as the illustrations show, less of these exotic materials are necessary, due to the ultralight nature of the structure. Cloth for the sail would have to be made from an extruded carbon/carbon composite and woven in a very precise way, so that the small surface area to volume ratio may be used to transfer hear away from the vehicle. The design of the cross-sections of the filaments is at an early stage of development, but the cloth can have a greater surface area on its leeward side, in order to radiate heat more quickly. It may also be beneficial to make the sail porous to some extent, allowing a small percentage of the boundary layer to penetrate the cloth, thus aiding the transpirational cooling of the wing surface. Leading edge sharpness may be maintained using a laminated carbon composite which has a hardened centre, with progressively less hard layers fused to it. This material will erode differentially, so that the leading edges always stay sharp, even when erosion rates may be severe, as in an atmosphere entry at interplanetary velocity. Page Two Page Four

Hypersonic Flexwings Pages

Introduction

Part One Part Two Part Three

TERRESTRIAL HYPERSONIC FLEX-WING (THF)

INTERPLANETARY MEGASONIC FLEXWING (IMF)

AERODYNAMIC CONTROL AND MASS SHIFT

CONCLUSIONS

REFERENCES

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