Namerical Optimization of Weight and Velocity of a Tunneled High Speed Hull, Using Tagouchi Method

In this study, the usual shape of a specific mono-hull changes into tunneled one keeping the geometrical parameters, including deadrise angle, keel line, beam width, and the hull length, constant.In this research, the specific shape of a speed monohull changed into a tunneled, keeping the geometric parameters, including the deadrise angle, keel line, hull width and length constant. The analysis carried out considering full load (10kg) and without load (3kg) conditions and optimization of the tunnel dimensions was performed in the maximum operational weight (10kg) and velocity (10m/s). Various geometrical parameters are effective on drag reduction of different sections of the tunnel, when designing and manufacturing the hull. In order to reduce drag, various geometrical parameters in different parts of the tunnel are effective in design and optimization. In this study, it has been attempted to investigate the effects of three parameters, namely: tunnel aperture, tunnel height, and blade simultaneously, in order to achieve an optimum shape of the tunnel. For this purpose, numerical simulation of the problem was carried out by means of finite volume method, considering moving mesh. For turbulence modeling, k-ε model and for simulating the free surface, volume of fluid (VOF) method were employed. The design of test and optimization were conducted, using Taguchi method. The results show that the tunnel aperture is the most effective parameter in increasing operational speed. Furthermore, one can reduce the drag by about twenty percent in the operational weight and speed through optimizing the tunnel.