基于AMESim的冰区船舶轴系扭转振动仿真

Torsional Simulation for Propulsion Shaft of Ice Class Ship by Software AMESim

用AMESim软件建立轴系冰载荷扭转振动仿真模型,对一艘1A冰级多用途船推进轴系进行仿真计算。考虑柴油机调速器对冰载荷冲击导致的轴系转速下降的响应,且柴油机的气体激励力矩和往复惯性力矩随轴系转速的变化而变化。将AMESim的计算结果与系统矩阵法的计算结果作对比,以验证其可靠性。对冰载荷扭转冲击进行了仿真。结果表明,在冰载荷冲击下,轴系转速有很大的下降,当转速下降到柴油机主谐次临界转速附近时,冰载荷激励和主谐次激励出现瞬态叠加,扭转振动响应达到最大值。此外,修改柴油机扭矩限制以提高扭矩余量,这是减少速度下降的有效方法。

A torsional vibration model of propulsion shaft under ice impact was built with software AMESim. The response of engine governor to the drop of engine speed was considered. Gas pressure and oscillatory inertial force changed with the engine revolution. The AMESim model was verified by comparing the result of system matrix method at slowly running up condition. The results of ice impact simulation show that the vibration torque reached its maximum when the engine speed dropped down and near to the critical engine speed in main order. In addition, increase of the margin of engine torque by changing the torque limit is an effective way reducing the drop of engine speed.