Abstract: Aiming at predicting the hull thrust at the preliminary design stage for a tunnel thruster, an RANS (Reynolds-averaged Navier-Stokes) simulation method incorporating the body force model for the rotor is studied. Considering the big loading distribution difference between the open propeller and the tunnel thruster, common body force models are not suitable for the tunnel thruster. According to the cha-racteristic loading distribution of tunnel thruster rotor blades, a new body force model is proposed. To account for the blockage effect of the rotor, we propose a flow rate correction approach, together with empirical formulas of the flow rate correction coefficient for the cases of with and without the gearbox. Numerical examples indicate that the present method is capable of predicting the hull thrust, and hence the rotor thrust, and determining the required thrust with reasonable accuracy. Besides, the body force-based simulation method can also be applied to simulating the ventilation phenomenon of tunnel thrusters.

Key words: tunnel thruster, computational fluid dynamics(CFD), body force model, flow rate correction, ventilation