OpenPlaning: Open-Source Framework for the Hydrodynamic Design of Planing Hulls

The use of Dr. Savitsky's empirical methods for the hydrodynamic design of planing hulls is widespread in industry and academia. In spite of their common use, their implementations are frequently inconsistent among their users. This makes it difficult to share and replicate exact results, and apply those results to a reader's desired case study. This paper presents an open-source Python-based framework of the Savitsky '64 and Savitksy & Brown '76 papers that is suitable for industry and research purposes, named OpenPlaning. The original Savitsky method implementation required the use of charts and results interpolation to find the boat's equilibrium. OpenPlaning instead uses a root-finding algorithm to determine the equilibrium attitude, automating the process and assuring consistent use of the Savitsky method. This formulaic approach allows the users to change and explore variations among any desired hull characteristic (beam, deadrise, weight, flap size/deflection, etc.), and use Python packages to optimize these parameters. OpenPlaning includes Faltinsen's 2010 planing hull porpoising inception work, which expanded upon the Savitsky method to estimate the vessel's mass, damping, and restoring coefficients. Consequently, control engineers can also use OpenPlaning to obtain a linear system in the heave and pitch degree of freedoms, and obtain initial tuning parameters for control systems. To illustrate the use of OpenPlaning, an example planing craft is designed, explored and optimized with real-world constraints.