Effects of Key Process Parameters on the Impact of HTPB Propellant by a High‐Pressure Liquid CO ₂ Jet

ABSTRACT To address the safety and environmental concerns of conventional water jets in hydroxyl‐terminated polybutadiene (HTPB) propellant processing, a high‐pressure liquid CO 2 jet is proposed for fragmentation. An experimental platform was established to systematically investigate the effects of jet pressure, standoff distance, and nozzle diameter via single‐factor and Taguchi orthogonal experiments. Results indicate that impact efficiency increases with jet pressure, with depth and area rising sharply beyond 25 MPa and 30 MPa, respectively. Efficiency decreases with standoff distance; increasing it from 5 to 11 mm reduces maximum depth and area by 51% and 62%. Nozzle diameter enlarges the damaged area, while depth peaks at 1.5 mm. Orthogonal analysis reveals the dominant parameter for depth is pressure > nozzle diameter > standoff distance (optimal: 35 MPa, 5 mm, 1.5 mm), and for area is nozzle diameter > standoff distance > pressure (optimal: 35 MPa, 5 mm, 2.0 mm). Compared to water jets, liquid CO 2 jets produce a damaged area up to 248.2 mm 2 , approximately 4.9 times larger, confirming its feasibility and advantages for safe, eco‐friendly propellant disposal.