Sequential Design Space Exploration of a Wind-Assisted Ammonia Tanker Hull using the VPP Derivative Method

Kurzfassung

Wind-assisted ship propulsion (WASP) technologies represent a promising means to adhere to defossilisation regulation, while ensuring an economic ship operation less dependent on volatilities in fuel prices. Unlike conventional ships, WASP ships often operate at static drift and heel, which may induce substantial added resistance. Thus, optimisation of hull and appendages offers significant potential. However, applying a Velocity Prediction Program (VPP) with high fidelity inputs through CFD simulation to evaluate performance for each design iteration is computationally prohibitively expensive. This paper applies the previously developed, more efficient VPP derivative method, a gradient-based approach evaluating key performance drivers, that significantly reduces the number of required high-fidelity RANSE-CFD simulations. The method’s practicality is demonstrated through a sequential design space exploration of hull and appendage design using the case study of a 130 m carbon neutral wind-assisted ammonia tanker operating on two different offshore routes. A range of key parameters are explored, including the beam-to-draught ratio, deadrise angle, skeg geometry, and centreboard placement. Results show that a keel-like skeg with a pronounced leading edge, a retractable high aspect ratio centreboard, an un-immersed transom, and a moderate deadrise are especially beneficial for the vessel’s overall performance. The study showcases the VPP derivative method as a low-cost, high-fidelity tool to enable optimisation of wind-assisted ships across a large design space, contributing to the development of sustainable sea transport.