Hydrodynamic Performance Improvement of a Tirhandil Yacht by Stern Form Modifications

This paper presents a comprehensive investigation to improve the hydrodynamic performance of a Tirhandil hull form by modification efforts on the stern region. The form improvement approach combines computational fluid dynamics (CFD) methods with computer-aided design (CAD) systems. The design process for the reference and modified models was carried out by using CAD systems. The hydrodynamic characteristics of the reference hull form were evaluated by employing CFD methods and it was determined that form improvements should be concentrated on the stern region. The modification process was conducted by considering constraints on the design variables in the stern region and the main dimensions of the reference model. A grid independence study was performed to evaluate various grid structures to determine the optimal mesh configuration for the numerical analyses. The SST k-Omega turbulence model was used for the numerical analyses to simulate turbulence structure around the hull form. Achieving around a 13.4% reduction in the total resistance coefficient, the modified model also exhibited decreased wave amplitudes, smoother wave transitions, and a significant reduction or cancellation of shoulder and stern waves.