Characterization of the Flow Field of a Submerged Jet Based on Large Eddy Simulation

Submerged water jets are widely used in underground engineering for coal breaking. This study aims to clarify the flow field characteristics and momentum transfer mechanism of submerged jets. We employ large eddy simulation (LES) in conjunction with contact mechanics and the jet momentum theorem. A numerical model of a submerged jet impinging on a coal surface is established to quantitatively analyze the velocity and pressure distribution of submerged jets under different jet pressures. The LES method accurately captures the large-scale vortex structures of the turbulent flow field. The circular uniform pressure theory of contact mechanics explains the pressure distribution on the jet impact surface, and the jet momentum theorem reveals the momentum transfer law during jet propagation. The results show that at a jet pressure of ۱۰ MPa, the jet core length exceeds ۵۰ mm, ensuring effective coal-breaking impact capacity. A cavitation-induced gas film envelops the jet, suppressing dispersion and preserving jet energy, with a positive correlation to jet pressure. The maximum wall impingement pressure increases with rising jet pressure. A jet pressure of ۳۰ MPa significantly enhances the intensity of the high-pressure impact zone. By contrast, pressures below ۳۰ MPa primarily expand the impact coverage without a pronounced strengthening of the high-pressure core.

کلیدواژه ها:

Submerged jet ، Water jet coal breaking ، Large eddy simulation ، impact pressure ، Flow field characteristics