CFD Automated Self Propulsion Test

CFD simulations are becoming more and more reliable and the increasing computational power are making them a convenient tool to investigate complex phenomena and to reproduce the experimental tests. In the hydrodynamic design process the correct evaluation of the self propulsion performance is an essential item to access the true performances of the ship. This paper deal with a CFD methodology, developed in STAR-CCM+, that reproduces the self propulsion experimental test. The variation of propeller rpm has been automated in order to achieve the self propulsion condition. Ship motions and free surface are take into account to study the behavior of the propeller in the real wake and to compute the propeller efficiency and the absorbed power. A sliding rotating mesh encloses the propeller while the mesh motions, necessary to simulate correctly the ship trim and sinkage, are managed by a STAR-CCM+ proprietary algorithm. The towing force has been take into account in order to reproduce the load variation test. The numerical results are presented in this article and are compared with the experimental results. The good match proved that the numerical self propulsion simulations are getting an extremely useful tool in the hydrodynamic design.