Ahmad Reza Kohansal

The submarine is one of the most complex structures made by humans . This submarine operates in three areas of surface, submerged and semi-submerged navigation, which indicates the very complex design of this model of offshore structures. At the beginning of this dissertation, different types of submarines are introduced and scientific works done in this field are mentioned. In the next step, using STAR CCM software and finite volume method, resistance validation test was performed with the experimental results obtained in submerged water mode for SABOF submarine. Then, due to the movement of this submarine in the submerged and surface mode, it is necessary to study the flow around the submarine body in different landing numbers and different operating modes, the results of which show a direct relationship between speed and compressive and frictional resistance. Then, due to the importance of waves on compressive strength and subsidence resistance, simulations have been performed under regular waves and at different landing numbers. With domain of wave length frequency reduction pitch. Increasing the number of landings and the speed of the vehicle has a direct effect on increasing the turbulence around the submarine. The effect of submarine immersion is further investigated. As the immersion height increases, the effect of the waves on the subsurface decreases so that if the immersion rate exceeds half the wavelength, its effect on the device tends to zero. Therefore, by increasing the operating depth, the range of motion and fuel consumption can be reduced .