Numerical Simulation of Emergency Rising of A 6-DOF Submarine

In this paper, submarine motion is studied during emergency rising maneuver and blowing air in the main ballast tanks (MBTs). In emergency rising, the MBT plays an important role in the submarine motion. In an emergency situation, the stored compressed air is blown into the MBTs. Reducing the weight of the submarine causes the submarine to rise. Although blowing process may be done in an emergency situation but it is very effective in the maneuverability of submarine. Hence, this paper aims to consider the blowing process and effect of parameters in the emergency rising maneuver. A 6-DOF submarine with four MBTs is considered. The equations of motion are derived and blowing air to the MBTs is modeled by compressible isentropic flow. Simulations are carried out for a typical submarine. The behavior of submarine is investigated in the emergency rising maneuver. Also, the effect of different parameters such as intake air characteristics on the angle of attack and drift and climbing time are studied. The results show that the rising time can be reduced by increasing the pressure of stored air and turning elevators.