Thermal Protection Systems for Hypersonic Artillery Projectiles

Artillery projectiles are being designed for use at hypersonic speeds making the need for thermal protection systems inevitable. While thermal protection systems (TPS) for hypersonic vehicles have been extensively explored since the 1950s, however the use of TPSs to gun-launched projectiles is a new application. The major bottleneck for this new application is the extreme environment that occurs within a gun barrel during firing of a projectile. The rapid acceleration of the projectile produces high set back/forward, balloting, and angular acceleration loads that can cause the projectile to deform transiently and current TPSs to fail as they are too brittle for this application. For a hypersonic projectile, the TPS must be capable of conforming to the geometry of the projectile and withstand up to 1000W/cm2 of heat flux for 5 minutes. For the maximum payload of the projectile to be maintained the TPS must be no thicker than 5 mm, a capability that many current TPSs cannot achieve. Therefore, there is a critical need to develop a TPS for the hypersonic artillery shell application that is durable, ductile, thermally protective, conformal, and thin.