Presentation of a Computational Model for Performance Evaluation of Two Stepped Hulls in Calm Water

Stepped planning hulls are one of the main innovations in the field of hull hydrodynamics which lead to wetted surface reduction and performance improvement. Nowadays, many of boat building industries such as Madera use stepped hulls design. However, there is no simple method for performance prediction of such hulls. Therefore, the main aim of the current study is development of a mathematical model for trim and resistance prediction of two stepped hulls. The basic of mathematical model is similar to Savitsky64. Presented mathematical model divides the two stepped hull to three parts and by assuming linear flow separation from steps, wetted surfaces are recognized. Finally, using an iterative solution, trim and resistance of two stepped hull are obtained. For validation, the obtained results using mathematical model are compared against experimental data of Southampton series model C2. Comparisons prove the capability of presented mathematical model for appropriate performance evaluation of two stepped hulls at conceptual design phase.