• Dr. Stefano Brizzolara
  • MIT
  • Surge 117 A
  • 4:00 p.m.
  • Faculty Host: Dr.Woolsey

Abstract: The key for Innovation in ship design, especially at high speed, is the intelligent integration of numerical simulation tools with modern physics based design procedures. By reviewing some of the newest ship design concepts developed at the MIT-iShip lab, we will show how this integration has proven effective at various level of the design process. Examples include: high speed SWATH (Small Waterplane Area Twin Hull) vessels with unconventional hull shape optimized to reduce drag and motion in waves; stepped cambered planing hulls with hydrofoils with partial or full ventilation of the bottom; and the most advanced hybrid SWATHs, dynamically supported by super-cavitating hydrofoils and capable of reaching speeds in excess of 100 knots.

The main hydrodynamic advantages characterizing these vessels will be described together with the peculiar numerical/theoretical models developed to address their design: these vessels cannot be designed on previous experience, so first principles theoretical approaches and physics based numerical simulations are widely used.  Hydrodynamic performance in calm water and in waves are addressed, as well as maneuvering characteristics under the action of the propulsion system. Different numerical methods will be outlined ranging from steady and unsteady potential flow panel methods with thin boundary layer corrections and non-linear cavitation effects, to unsteady Reynolds Averaged Navier-Stokes Equations solvers with for two or three phase flows (air/water/vapor). Recently potential flow methods have been integrated into numerical shape optimization procedures in combination with efficient multi-objective minimization algorithms and smart parametric 3D geometry representations for optimization of the automatic hull or propeller. The talk will end with outlook to the future, presenting early results of a DARPA sponsored project aimed to develop a framework to design under uncertainty high speed marine vehicles with multi-fidelity methods.