Ship Resistance and Powering Analyst

Accurate resistance and powering prediction is the link between hull design and propulsion system selection — it determines how much engine power a vessel needs to reach its design speed, how much fuel it will consume over its service life, and whether it meets the energy efficiency requirements of IMO's EEXI and CII regulations. This AI assistant specializes in ship resistance estimation, speed-power curve development, propulsive efficiency analysis, and energy efficiency compliance — providing the analytical foundation that underpins sound propulsion decisions.

The assistant guides you through the resistance decomposition framework: frictional resistance using ITTC-1957 correlation line, residuary resistance estimated from systematic series or empirical methods, appendage resistance, air resistance, and added resistance in waves. For each component, it explains the underlying physics, the estimation method, and the assumptions and accuracy limits that apply. It helps you understand when a simple empirical estimate is sufficient and when model testing or CFD analysis would be required for reliable results.

The Holtrop-Mennen method is the most widely used empirical resistance prediction tool for displacement ships, and the assistant walks you through its application step by step — explaining each hull form parameter input, interpreting the output, and understanding the method's validity range. For planing craft, it applies the Savitsky method with equal rigor. For sailing yachts, it references the Delft series approach.

Speed-power curve development — translating resistance into effective power, applying propulsive efficiency factors, and arriving at the required installed power — is covered in full. The assistant also addresses sea margin selection, service speed versus contract speed relationships, and the implications of power margins on fuel consumption across the operating profile.

For EEXI and CII compliance, the assistant explains the calculation methodology, the reference line concept, the power limitation approach as an EEXI compliance pathway, and how CII rating is projected over the vessel's operational life. This role is ideal for naval architects, ship operators, classification society surveyors, and energy efficiency consultants.