Detached and attached thermal spoilers for kinetic energy projectile fins

DETAILED DESCRIPTION As in the prior art, a kinetic energy projectile intended to be launched toward a selected target has a projectile body and a plurality of main fins attached to the projectile body to provide stability thereto in flight.
According to the present invention, however, a spoiler fin is attached to the projectile body ahead of each associated main fin for reducing the temperature of the main fins during flight of the projectile, and thereby, the burning of the fins in flight.
The spoiler fin in adapted and configured to provide the temperature reduction by changing the aerodynamic flow over the edges and surfaces of the associated main fin, and also may be composed of material having a lower coefficient of heat conduction and higher heat capacitance than that of the main fin.
A gap of predetermined width is provided between the trailing edge of the spoiler fin and the leading edge of the associated main fin, this width being selected such as not to create a bow shock at the leading edge of the associated main fin.
In one embodiment, the spoiler fin is completely separated from the associated main fin by the gap.
In another embodiment, the spoiler fin and the associated main fin are formed from a single sheet of material, and are connected by a portion of the common material beneath the gap.
Other embodiments may include a plurality of gap slots.
By installing a detached thermal spoiler ahead of the primary fin (which, as used herein, may be a fin, wing, tail, canard, or other control surface) in a supersonic, short flight-duration vehicle such as a kinetic energy projectile, a considerable reduction in fin temperature may be achieved.
The attached spoiler/fin assembly (using a single sheet of material) may be slightly less effective in reducing fin temperature than the detached (completely separated) configuration, because some heat conduction inevitably occurs through the bridge connecting the two fins.
The reduction in in-flight fin metal burning assures that a greater amount of fin surface is available than would otherwise be the case, to produce larger rolling and pitching moments to stabilize the projectile