Our proposed HPC project aims to advance the sustainability and energy efficiency of commercial shipping through high-fidelity hydrodynamic and structural analyses. The maritime sector is under increasing pressure to reduce fuel consumption and greenhouse gas emissions, and achieving these goals demands a deeper understanding of hull–propeller–rudder interactions, viscous flow phenomena, and structural response under realistic loading conditions. High-performance computing is essential to performing simulations with the required resolution, accuracy, and throughput. The project integrates Computational Fluid Dynamics (CFD), Experimental Fluid Dynamics (EFD) data assimilation, and Finite Element Method (FEM) structural analysis to create a comprehensive digital framework for ship design and performance optimization. On the hydrodynamics side, we will conduct large-scale CFD simulations to analyse flow around the hull, propeller, rudder, bilge keels, and other appendages. These simulations will include RANS and hybrid RANS–LES turbulence modelling, cavitation prediction, wake field characterization, and propulsion efficiency studies. Our objective is to identify flow-induced losses, quantify pressure distributions, and evaluate design alterations that can reduce drag and improve propulsive efficiency. Parallel to this, we will incorporate EFD measurements, such as towing-tank tests, PIV velocity fields, and cavitation tunnel observations, to validate and calibrate numerical models. The combination of CFD and EFD allows us to validate our simulation-driven recommendations. Structural analysis will be carried out using advanced FEM simulations to evaluate global and local stresses, vibration response, and fatigue life of the hull and propulsion components. We will study load cases arising from hydrodynamic excitation, propeller-induced pressure pulses, and fluctuating wake patterns. Coupled CFD–FEM workflows will be used to assess fluid–structure interaction effects and ensure that hydrodynamically optimized designs remain structurally sound and durable. The computational requirements of this project are substantial. High-resolution CFD grids (20–100 million cells), transient simulations, and parametric design sweeps necessitate parallel scalability and large memory capacity. The expected outcomes include improved hull and appendage shapes, optimized propeller–rudder combinations, reduced cavitation and vibration, and enhanced structural reliability. Collectively, these improvements contribute to lower fuel consumption, extended component lifetime, and reduced environmental impact. The project will also generate validated datasets and reusable workflows that can support future research and industry adoption of energy-efficient ship designs.