The transient sloshing in laterally excited horizontal elliptical containers with T-shaped baffles is first investigated by using a novel semi-analytical scaled boundary finite-element method (SBFEM). The proposed method combines the advantages of the finite-element and the boundary element methods (BEMs) with unique properties of its own, in which a new coordinate system including the circumferential local coordinate and the radial coordinate has been established. Only the boundary of the computational domain needs to be discretized in the circumferential direction as the same as the BEM and the solution in the radial direction is analytical. Assuming ideal, irrotational flow and small-amplitude free-surface elevation, the formulations (using a new variational principle formulation) and solutions of SBFEM equations for an eigenvalue problem under zero external excitation (free sloshing problem) are derived in detail. Subsequently, based on an appropriate decomposition of the container-fluid motion, and considering the eigenvalues and eigenmodes of the above eigenvalue problem, an efficient methodology is proposed for externally induced sloshing through the calculation of the corresponding sloshing masses and liquid motion. Several numerical examples are presented to demonstrate the simplicity, versatility, and applicability of the SBFEM during the simulation of sloshing problems of complex containers, and excellent agreement with the other methods is observed. Meanwhile, three T-shaped baffle configurations are considered including surface-piercing baffle, bottom-mounted baffle and their combination form, and Y-shaped configuration evolved from that of T-shaped baffle has been taken into consideration as well. The liquid fill level, arrangement and length of those baffles affecting the sloshing masses, and liquid motion are investigated in detail. The results also show that the present method can easily solve the singularity problems analytically by choosing the scaling center at the tip of the baffles and allows for the simulation of complex sloshing phenomena using far less number of degrees-of-freedom.

An entrance channel is dredged when its natural dimensions are not adequate to accumulate more and larger ships. Considering the reconciliation among costs, safety and efficiency and the complex relationship among channel type, navigable water level and sailing speed, a simulation-based optimization framework is proposed to optimize channel dimensions with limited dredging budget constraints in an integrated way. In this framework, the optimization program generates channel dimensions acceptable for safe navigation with budget constraints, and seeks an optimal balance between the dredging costs and navigation efficiency, including vessel waiting time and berth utilization. The simulation model evaluates the values of navigation efficiency measures considering the randomness and dynamics in ship operation. Finally, an application is given and the results show that the proposed framework is effective and helpful for optimizing the dimensions of the entrance channel. Moreover, the proposed modeling and solution methods are general and can be applied to the port basin, anchorage area as well.

Yard crane operations are often a bottleneck at a container terminal. This paper aims to investigate the effects of various real-time yard crane dispatching strategies on operational cost and gross crane rate (GCR) for nontransshipment container terminals. A general cost estimation model is introduced to incorporate the detailed costs incurred during container handling process within terminal area. The formulas of container handling related parameters are mathematically derived to validate the simulation model. Results reveal that the common nearest truck first served strategy yields the lowest operational cost but the lowest GCR. On the other hand, earliest YT strategy achieves the highest GCR at the expense of higher operational cost with more vessel calls, while nearest YT strategy produces the highest GCR and is the second economical with fewer vessel calls. Under any of the proposed yard crane dispatching strategies, the strategy that separately stacks import and export containers into different blocks outperforms the scattered stacking strategy in terms of GCR, although no distinct cost advantage is obtained. The results provide fundamental insights into the connection between real-time yard crane dispatching strategies and operational performance at manually controlled nontransshipment container terminals.