Mitigating hypersonic heat barrier via direct cooling enhanced by leidenfrost inhibition

Heat barrier, the unrestricted increase in airplane or rocket speeds caused by aerodynamic heating, which—without adequate provisions for cooling the exposed surfaces—can lead to the loss of a hypersonic vehicle’s reusability, maneuverability, and cost-effectiveness. To date, indirect thermal protection methods, such as regenerative cooling, film cooling, and transpiration cooling, have proven to be complex and inefficient. Here, we propose a direct liquid cooling system to mitigate the heat barrier, utilizing a blunt-sharp structured thermal armor (STA)—a recently proposed material [36] to elevate the Leidenfrost point. The fiber-metal nano-/micro-STA withstands rigorous simulated hypersonic aerodynamic heating using butane and acetylene flames, ensuring effective temperature management in scenarios where flame temperatures reach up to 3000 °C—far exceeding the melting point of the STA substrate. Systematic cycling and durability tests further confirm the STA’s exceptional tolerance and robustness under extreme conditions. This work offers an efficient thermal protection method for hypersonic vehicles.