Study on the Dynamic Characteristics and Aging Mechanism of Water Jet Impact in Boreholes Under Temperature Coupling Effect

Abstract The impact efficiency of water jets is closely associated with their transient characteristics and thermal effects. However, existing studies have predominantly focused on macroscopic impact effects, largely overlooking the intricate dynamic processes, which hinder a systematic understanding of how temperature variations influence the dynamic behavior of jets and, consequently, constrain the precise control and efficiency optimization of water jet technology. To address this issue, this study employs numerical simulations to systematically investigate the dynamic response and thermodynamic behavior of water jet impact in boreholes under various pressure and temperature conditions, thereby elucidating the dynamic impact characteristics induced by thermal coupling effects. The results indicate that the impact flow and temperature fields of the drilling water jet exhibit distinct time-dependent characteristics. Impact disturbance is positively correlated with pressure, while temperature variations have a minimal effect. At 16 MPa, the peak axial velocity of water jet impact across temperatures is 185.67 m/s, and peak wall velocity is 79.78 m/s, with both velocity distributions remaining relatively consistent. Temperature significantly affects the thermal effect: at 333.15 K, the temperature change caused by impact is 1.83 times greater than at 293.15 K. Based on these findings, optimization recommendations for water jet technology are proposed, considering energy synergy principles, to provide theoretical support for enhancement and optimization of hydraulic measures.