喷水推进两栖车水上自航性能CFD模拟研究

CFD Simulation Study on the Self-propelled Performance of Amphibious Vehicle Powered by Water-jet Propulsion Pump

针对两栖车与泵推进器推力的动态耦合模拟问题,建立一种结合非惯性系的泵转子/车体流固耦合高效模拟方法;提出两种在指定航速下获得泵推进器匹配转速、车体自航状态及其水动性能的计算流体力学(Computational fluid dynamics,CFD)模拟方法。将上述方法在Simcenter STAR-CCM+软件中进行运用,得到在不同指定航速下的两栖车自航静水阻力、姿态及泵推进器匹配转速的规律,并通过试验数据验证数值方法的准确性。同时,为减小两栖车水动阻力、降低推进泵转速,提出一种在原型车前轮底部增加挡板的减阻方案,并通过数值方法分析挡板对车体减阻及推进泵匹配转速的影响规律。

Aiming at the dynamic coupling simulation between amphibious vehicles and pump thrusters,an efficient simulation method of fluid-structure interaction combined with non-inertial frame is established.Two simulation approaches for obtaining the matching speed of the pump thruster,the self-propelled attitude of the vehicle and its hydrodynamic performance at some specified sailing peed are proposed.The Simcenter STAR-CCM+software package is used to numerically obtain the hydrostatic resistance,attitude and pump thruster matching speed of the amphibious vehicle at different specified speeds under self-propelled conditions,and the accuracy of the numerical method was verified by comparison with experimental data.Meanwhile,to reduce the hydrodynamic resistance of amphibious vehicles as well as the speed of the pump,a drag reduction scheme which employs a baffle at the bottom of the front wheel of the prototype amphibious vehicle is proposed,and the influence of the baffle on the drag reduction of the vehicle and the matching speed of the propulsion pump is also analyzed numerically.