Optimization of Regenerative Cooling Channel Topology for LOX/Methane Engine Throat Section under Extreme Thermal Conditions

Reusable rocket engines face extreme thermal challenges, particularly in critical regions such as the convergent section and throat, where conventional milled-channel regenerative cooling systems struggle to adapt to complex thermal environments. The use of liquid methane—a cryogenic hydrocarbon propellant—further complicates heat transfer due to flow inhomogeneity and transcritical phenomena. To address these limitations, this study introduces a fluid-solid coupled topology optimization (TO) methodology for designing advanced regenerative cooling channels in a liquid oxygen/methane engine’s convergent-throat assembly. By integrating temperature minimization and pressure drop reduction objectives, we generated multiple topology-optimized configurations through mathematical algorithms to determine optimal material distributions, enabling unprecedented design flexibility and precision. High-resolution three-dimensional numerical simulations revealed two critical mechanisms in supercritical methane transport: vortex generation and dissipation at flow junctions enhance convective heat transfer through intensified turbulence, while cross-sectional abruptions induce flow separation and turbulent mixing in supercritical fluids, improving thermal efficiency while mitigating thermal acceleration effects. Compared to conventional milled-channel designs, the TO-optimized structure achieves a maximum temperature reduction of 7% and pressure drop decrease of 14%, while maintaining structural integrity under extreme thermomechanical stresses. This research validates topology optimization as a transformative approach for rocket engine thermal management, demonstrating its potential to enhance cooling efficiency, reduce energy losses, and improve reusability in next-generation methane-fueled propulsion systems operating under aerospace extreme conditions..