以预报侧推器初步设计阶段的船身推力为主要目的,研究基于体积力的侧推器流场的RANS(Reynolds-Average Navier-Stokes)模拟方法.考虑到敞水桨与侧推器转子的负荷分布差别较大,常用的敞水桨体积力模型对侧推器并不适用,基于后者的负荷分布特征,建立了转子体积力模型,提出了考虑转子阻塞影响的流量修正方法,并给出了有、无齿轮箱时流量修正系数的经验公式.算例表明,文中方法能够对船身推力进行较准确的预报,从而较准确地确定转子推力的设计值.同时该方法还可用于侧推器吸气现象的模拟.
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.
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