Numerical investigations of chamber floor ports system

The dynamically balanced systems are widely used in high-head locks. However, due to numerous branch culverts and diversion points, the structure of the system is highly complex. To address this problem, this paper, inspired by the German pressure chamber system, proposes a new leveling system—the Chamber Floor Ports system. The new system is investigated numerically using a “hybrid model” approach that combines a full-scale Computational Fluid Dynamics model with a local generalization model. The study shows that vortices induce transverse asymmetric (Q_dev < 1) outflow of ports near the chamber center in the sections e and b, creating uneven jet distributions and strong transverse forces. In contrast, the terminal ports of sections e and b and all of sections a and f experience minimal vortex influence, maintaining symmetric outflow (Q_dev ≈ 1) with correspondingly smaller transverse forces. The outflow in section e is symmetric (Q_dev ≈ 1) to section b in the longitudinal direction, resulting in a small longitudinal force in the middle of the chamber where the ship is moored. The pressure distribution demonstrates vortex-induced pressure reduction in the center of the pressure chamber, causing poor outflow uniformity in sections e and b (Flow Nonuniformity Coefficient ∈ [0.8, 1] in sections e and b). The analysis shows that the longitudinal diffusion range of vortices increases quadratically with the increase in the velocity of the impinging jet due to the strong wall-effect. An empirical equation describing the longitudinal diffusion range of bounded vortices is then proposed based on this relationship.