Propagation characteristics of ship waves in navigation tunnel and its influence on continuous navigation safety of ship

Abstract

In parallel to the construction of navigable tunnels which is gradually put on the agenda in China, more and more navigable tunnels are bound to be built. However, the relevant technical support is still extremely lacking. The existing engineering design and construction only refer to the construction experience of various traffic tunnels or the inland waterway navigation regulations, which in turn creating a limitation that the influence of navigable hydrodynamic environment is not considered. Therefore, to fill in the gaps in the research on key technologies of ship navigation safety in navigable tunnels, the open-source package FUNWAVE-TVD based on completely nonlinear Boussinesq equation has been used to establish a numerical model, demonstrating ship travelling wave motion in navigable tunnels in linear canals. The model can help to determine the ship model by pressure source terms. The model size and research conditions are determined according to the inland river navigation code and existing engineering examples. The accuracy of the model is evaluated using numerical verification, grid convergence analysis and ship travelling wave stability. The temporal and spatial distributions of height and velocity of the solitary wave induced by ships in navigable tunnels are analyzed. The safety impact of ship travelling wave in navigable tunnels on continuous navigation is discussed. The results show that the model has a great ability to capture the propagation and evolution process of ship travelling wave in navigable tunnels. It is pointed out that large fluctuations are easily formed on both sides of the quay wall of the navigation tunnel and in the middle part. The multiple nonlinear regression equation containing the maximum solitary wave height η max, ship draught P , Fr , water depth, width of navigation tunnel and ship type is obtained. The equation shows that the maximum solitary wave height gradually increases with the increase of ship draught and Fr , but vice-versa with the increase of water depth, width and section coefficient of navigation tunnel. It is found that the wave velocity of the front solitary wave surface is in good agreement with the theoretical solitary wave surface equation. Taking the theoretical wave velocity of the solitary wave as the propagation velocity, the safe sailing distance of the ship during the continuous navigation, especially under the conditions of large speed and draught in existing navigation tunnels, is obtained. The novelty of this paper is serving as a reference and basis for the design of navigation tunnels in single-line straight canals and playing a role as a theoretical foundation for the formulation of any key technical standards or specifications for navigation safety of ships in navigation tunnels.