The increasing magnitude and frequency of storms driven by climate change have increased global demand for flood protection barriers. Sector gates are one of the barrier types, providing storm surge protection while letting marine traffic pass during normal conditions. However, no dedicated design guidelines currently exist for these structures, and the uniqueness and large scale of sector gates often make conventional design methods suboptimal.

This research investigates a method for determining wave-induced forces on sector gates using three-dimensional computational fluid dynamics (CFD) modelling with OpenFOAM and the Waves2Foam package. Accurate prediction of wave pressure distributions is essential for optimising sector gate design, and CFD offers a high resolution, which is an alternative to traditional physical and empirical approaches. The goal of this study is to evaluate the capability of 3D CFD modelling to analyse the spatial and temporal distribution of wave loads on complex geometries such as sector gates.

The St. Petersburg storm surge barrier was used as a case study. Two 2DV OpenFOAM models, based on Goda's experiments and the St. Petersburg case study, were developed. A 3D model for the St. Petersburg case study was then developed based on these results. The 2DV results showed good agreement with physical test data and confirmed that empirical methods tend to overestimate forces. It was further observed that maximum pressure occurs prior to the peak water elevation at the structure.

The 3D CFD model was simulated under a regular, non-oblique incident wave condition. Due to computational constraints, the model domain was limited to a single gate with a resolution of 12 cells per wave height. The maximum horizontal force obtained from the CFD model was 16.7 MN, falling within the range of 12.2 MN to 17 MN measured in physical model tests. However, minimum force predictions were approximately 50% lower than expected. The model identified critical loading areas, notably, at the junction between gates and at approximately two-thirds of the gate curvature from the junction point. Additionally, a node-antinode pattern in wave pressure along the barrier wall was observed, with extracted phase differences relative to the antinode at the junction between gates, providing further insight.


While significant computational resources are required, as the 3D CFD model took 2.5 weeks to simulate 250 seconds, the results demonstrate this method enhances understanding of wave-structure interactions under extreme conditions. It can be used to complement physical model testing in the detailed refinement phase of the design process.