
Lubricants, Journal Year: 2025, Volume and Issue: 13(2), P. 68 - 68
Published: Feb. 4, 2025
During slurry shield tunneling in hard rock or cobble strata, the discharge pipes suffer serve wear and damage. However, effect mechanism of pipe wall defects on flow characteristics two-phase is unclear. In this study, a three-dimensional particle model pipeline transport was established using coupled computational fluid dynamics–discrete element method (CFD-DEM) considering defect, typical forms straight 90° elbow were selected as research targets. The results indicated that localized defect can lead to increased inhomogeneity velocity distribution, generating low-flow zones resulting reduced rate stagnancy parts pipe. Meanwhile, local shape changes, so path through no longer smooth, causing more vortex/turbulence secondary flow, where an vortex promotes kinetic energy reduction creates larger pressure losses at elbow. addition, for without drop increases quadratically from increase 6.5% 16.9%, with maximum depth increasing 4 mm 19 mm. For linearly, 2.2% 10.2% paper investigates potential influenced by provides practical guidelines efficient operation circulating system.
Language: Английский