Turbidity currents occur widely in rivers, reservoirs, and estuaries, where their dynamics can be altered by lateral inflows from tributaries or drainage structures. However, the effect of lateral inflow on the formation and evolution of turbidity currents remains underexplored. The study details how variations in lateral inflow parameters (discharge and direction) affect the turbulence structure, interface entrainment, and energy conversion processes of horizontal lock-release turbidity currents at different densities of the initial dense fluid in a flume. Results reveal that the turbidity current evolves through three distinct stages under lateral inflow, including an initial disturbance near the inlet, full disruption by intense mixing with ambient fluid, and eventual re-plunging downstream. Stage transitions are quantitatively defined by critical densimetric Froude numbers (Fr′ 0.2 for disruption, Fr′ ≈ 0.48 for re-plunging). Within the full disruption zone, lateral inflow enhances entrainment and mixing, significantly inhibiting the development of Kelvin–Helmholtz instabilities. Then, the spatiotemporal evolution of the full disruption zone is quantified, revealing a significant positive correlation between its length and the ratio of injected lateral kinetic energy to the total mechanical energy of the turbidity current. Furthermore, prediction formulas for the disruption point location and full disruption zone length are established via multiple nonlinear regressions. Comparisons with simulation results demonstrate the high accuracy of these formulas. This work enhances the mechanistic understanding of turbidity currents and provides a scientific basis for managing similar flows in engineering systems.
Wang et al. (Fri,) studied this question.