Research on main control parameters for LCO₂ flash boiling abrasive jet based on ISRU on Mars

Space exploration and extraterrestrial resource extraction have emerged as comprehensive focal points in both major power strategic competition and the building of a shared future for humanity. The extraction of Martian resources and the construction of space bases all rely on stable and reliable supplies of energy and materials. Given the severe economic constraints of transporting materials from Earth orbit, in situ resource utilization (ISRU) technology on Mars demonstrates immense potential for locally producing required energy at lower costs, positioning itself as a critical breakthrough for space exploration. To harness the dominant CO₂ (≈96%) in the Martian atmosphere, a liquid CO₂ flash boiling abrasive jet technology for Martian energy extraction is pioneered.By mixing Martian dust as abrasives with pressurized CO₂ for injection, the technology leverages Mars’ vacuum environment to trigger intense flash boiling phase change, thereby accelerating abrasives for efficient rock fragmentation. Through a self-constructed visualization and rock erosion experimental platform, we captured the flow field evolution of the flash boiling abrasive jet and conducted erosion experiments on grey sandstone, confirming the feasibility of both jet formation and rock breaking. We proposed a multi-component, multi-feature Gaussian Mixture Model (GMM) to achieve effective segmentation of different phases in the flash-boiling abrasive jet. Combined with Proper Orthogonal Decomposition (POD), this approach clarified the dominant controlling parameters across various operating conditions. Furthermore, a GMM−Discrete Wavelet Transform (DWT)−based abrasive particle velocity extraction program was developed to characterize velocity distributions of abrasives at different stages and under diverse conditions. Both velocity distribution data and rock breaking results demonstrate that, for flash boiling abrasive jets, pressure differential is no longer the sole driver for abrasive acceleration, the gas generated by phase change effectively accelerates abrasives. However, excessive abrasives suppress phase change while impeding velocity enhancement via particle fluid interactions, thereby weakening both acceleration and rock breaking capabilities. This research not only enriches existing jet methodologies but also provides effective analytical tools for extracting solid-liquid-gas features in complex phase change jets with significant background interference.