en Ship Hydrodynamic مقاله پژوهشي Research Paper <p>Nowadays, application of high speed crafts with large tonnage is of our country&#39;s essences. In order to gain high speed, new multi hull crafts are traditional. A hull form having been used recently in frigates is the Trimaran. Trimaran hull form and motion have been extensively studied due to the development of numerical and analytical methods as well as the exploitation of experimental setup. In this article, we investigate the possibility to move the side hulls longitudinal and transversal with respect to the main hull in order to find the optimum situation for minimum drag. The mathematical approach is numerical method CFD with the help of VOF. Moreover the experimental measurement was provided for some cases. The simulation results indicated good agreement with the experimental results. The investigations undertaken within the scope of this article provide a starting point to investigate the flow pattern and performance of such ships.</p> Trimaran, Resistance, Piercing Bow, Experiment 33 40 http://ijmt.ir/browse.php?a_code=A-10-194-1&slc_lang=en&sid=1 karim akbari vakilabadi akbari.karim@gmail.com 10031947532846003292 10031947532846003292 Yes Marine Faculty of Imam Khomeini Maritime University Mohammadreza khedmai khedmai@aut.ac.ir 10031947532846003293 10031947532846003293 No Marine Faculty of Amirkabir University of Technology