A Comparative Study of Program FloSim Results Against SYRF Wide Light Project Data

In November, 2015, the Sailing Yacht Research Foundation (SYRF) published the tank test data from their "Wide Light Yacht Project" for the hydrodynamics of a modern, high performance, semi-planing yacht. This comprehensive data set, comprising canoe body with and without appendages in upright, heeled and yawed conditions, provides an important validation base for Computational Fluid Dynamics (CFD) codes. The SYRF report includes a number of comparative results from commercial CFD codes. In this paper, we present results computed using an advanced Boundary Element Method (BEM), FloSim, these calculations being compared against the test matrix of "Wide Light" measured data and also STAR-CCM+ RANS calculated results. Computer model preparation is discussed and FloSim and RANS case execution times and computer requirements are compared. FloSim is an unsteady, time-stepping BEM with a non-linear vortex wake rollup procedure and a coupled integral boundary layer method for viscous effects. The free surface wave development is treated with a non-linear procedure that includes a breaking-wave model to deal with excess wave energy issues. The program was developed specifically to bridge the gap between basic potential flow panel methods and RANS codes, with the objective of providing accurate, practical solutions on a laptop computer within a reasonable turnaround time and cost. In essence, the results presented in this paper demonstrate the development objectives have been achieved. The comparisons of FloSim's essentially "low-order" results against test data and STARCCM+ RANS calculations, provide a measure of tradeoff between calculation accuracy versus cost and turnaround time for a case.