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Today, the electrification of cars is widespread. However, the adoption of electric boats is not yet as common, partly due to the higher efficiency demands caused by the increased resistance in water. Hydrofoil technology offers a solution to this challenge. This technology uses wing-like structures, called hydrofoils, mounted below the hull. As the boat accelerates, the hydrofoils lift the hull out of the water, reducing drag and allowing for higher speeds and better efficiency. Hydrofoil technology and its associated hydrodynamics are complex. Therefore, being able to numerically model the phenomena associated with the technology is valuable for enabling improvements, fault detection, and optimization. For a hydrodynamic device operating close to the water surface, an important phenomenon is ventilation, where air is entrained into the water mainly due to pressure variations. Ventilation impacts drag and lift and can be either beneficial or unfavorable, depending on its nature and location. This thesis investigates the possibility of numerically predicting the ventilation and hydrodynamics for a vertical strut using the computational fluid dynamics software Star-CCM+ and the Volume of Fluid (VOF) method. Predicting ventilation through numerical simulations is computationally demanding. Therefore, the objective was to develop a model capable of predicting ventilation for a strut while keeping simulation time low. The study primarily focused on a specific strut geometry to analyze how ventilation varied with velocity. Additionally, another strut profile was included for comparison and to evaluate the model’s adaptability. The numerical model managed to capture the ventilation phenomenon within the velocity range of approximately 4-8 m/s using the Unsteady Reynolds Averaged Navier-Stokes (URANS) approach combined with the shear stress transport (SST) Menter’s k − ω turbulence model for the ventilated profile. These predictions were verified against available experimental data. However, at higher velocities, the accuracy of the predictions decreased. Consequently, it was concluded that further adjustments to the current numerical setup or investigation of alternative methods are needed, although this may compromise the goal of maintaining low simulation times.