Abstract
Hypersonic aerodynamic heating, also known as the heat barrier, is a dangerous energy form that humans have not yet fully overcome. The heat barrier has caused numerous catastrophic accidents and damage, as well as hindering the development of aerospace engineering. To date, indirect thermal protection methods, such as regenerative cooling, film cooling, and transpiration cooling, have proven to be complex, low in cooling efficiency, and detrimental to a hypersonic vehicle's reusability, maneuverability, and cost-effectiveness (RMC). Inspired by the latest Leidenfrost delay technology, we propose a direct liquid cooling technology to mitigate the effects of the heat barrier. Our proposed aluminum alloy-based structured thermal armor (STA) with a simple liquid cooling system, demonstrates the capability to rapidly mitigate simulated aerodynamic heating-induced extreme temperatures, exceeding 1400°C. This temperature is significantly higher than the melting points of conventional aircraft skin materials, such as aluminum alloys, which typically range from 600 to 700°C. Cycling tests indicate the STA's high durability and tolerance properties. Our research demonstrates that the STA is highly compatible with current hypersonic aerospace systems, promoting aerospace RMC. We also provide scale-up design guidelines for practical hypersonic vehicles' thermal protection. The STA offers a promising solution for hypersonic aerodynamic heating, providing a more efficient, durable, and cost-effective approach to thermal protection. This technology has the potential to revolutionize the aerospace industry, enabling the development of safer and more advanced hypersonic vehicles.