【作者】 杨晓光；

【导师】 陈浮；

【作者基本信息】 哈尔滨工业大学 ， 动力机械及工程， 2009， 硕士

【摘要】 潜射导弹的发射技术越来越受到各军事强国的关注,特别是由于潜艇在我国国防军事中的地位而使潜射导弹的发展更受重视。出水过程是潜射导弹能否成功发射的关键,各国均有因出水过程的干扰而导致发射失败的先例。出水阶段涉及两相交界,弹体会受海流、波浪和风速的综合影响,而气、水对导弹的作用特性差异很大,导弹受力会发生突变,其力学环境非常复杂。本文基于Fluent软件提供的物理数学模型,对潜射导弹的水下运动及出水过程进行了数值仿真。运用动网格技术实现导弹运动后计算域变形网格重构的计算,运用VOF(Volume of Fluid)模型模拟气、水交界面在导弹出水过程中的变形情况。基于三维的六自由度的模拟实现了流体力学和导弹刚体力学的耦合计算。本文对非结构化动网格划分进行了改进,采用了非结构化动网格和结构化静网格的综合求解,在精度相同的前提下,明显缩短了计算周期。探讨了三维计算和二维计算的区别,揭示了三维计算的优越性和合理性。在三维计算的基础上,对无动力潜射导弹水下运动和出水过程进行了系列仿真,探讨水深、潜艇速度、弹射速度对导弹水下和出水过程中运动学特性和动力学特性的影响。同时,对波浪的三维数值模拟进行了研究,得到了与理论相符的仿真结果。在以上计算的基础上,研究了波浪载荷对潜射导弹出水过程中姿态的影响。结果表明潜射导弹在不同水深相同的其它发射条件下其运动学参数和动力学参数的变化呈一定的模式化,变化规律基本相同,水深对导弹的影响主要体现在弹体应力方面;潜艇速度会明显改变导弹水下及出水后的姿态角,且其影响会随着水深的加大而放大。潜艇速度使弹道发生弯曲,弹体周围的漩涡结构明显不对称;弹射速度使导弹头部的高压和肩部的低压更加明显,肩部是易产生空泡的区域;同时,不管有无弹射速度,导弹水下运动阶段其轴向速度都会趋于一个平衡值;波浪对导弹的影响受波向、波高、出水速度、出水相位、出水姿态等因素的影响,有一定的随机性,本文研究的出水相位在波谷段,导弹出水后发生了明显与波向相反的偏移。最后本文对弹射方案与实验进行了对比,结果与实验相符,表明这种计算方法具有较高精度,可对水弹道和出水弹道预测提供指导意义。更多还原

【Abstract】 During the last decades, increasing attention has been paid on the launch technology of submarine-based missile in great-military-power countries, particularly for the important part of national defense and military affairs, remarkable emphases have been laid on it in Chinese as well. As the crux of this technology, water-exit course which involves in two-phase boundary used to result in precedent failure in certain countries. In this course, missile body is comprehensively impacted by such factors as ocean current, wave, wind and so forth. Moreover, the effects differ with each other significantly between gas and water. Consequently, the stressed condition varies to more complicated.The submarine movement and water-exit course are simulated with the model implemented in Fluent. The dynamic mesh is used to compute the change of the corresponding flow field boundary after the missile moving. VOF model is adapted to simulate the distortion of the free surface during the missile exit water. The simulation coupled the hydrodynamics and rigid body dynamics based on the 3D compute in 6 degree. The paper improves the mesh strategy by the combination of dynamic unstructured mesh and static structured mesh, shortens the periods. The study of the distinguish of the 2D and 3D revealed the 3D simulation is rational. Base on the 3D simulation, series of submarine-based powerless missile underwater launching processes are simulated to investigate the effects of the water depth, submarine speed, and launching speed on the movement and kinematic property. At the same time, the 3D wave is simulated, the result is in accord with theory. Based on the above study, the effect of the wave loads on the water-exit pose angles is investigated.The simulating results show that the kinematics and dynamic parameters change in the same model when the other launching conditions are the same in different water depth of the submarine, the water depth affect the stress of the missile body. The submarine speed will impact the water-exit pose angles, and the deeper of the depth, the worse of the water-exit pose angles. Moreover, the submarine speed curves the trajectory, and the evolution of the vorticity structure around the missile is unsymmetrical. Launching speed features the high pressure region on the top and the low pressure region on the shoulder of the missile, the shoulder of the missile is the location where the cavitation origins. Meanwhile, the axis velocity will tend towards balance velocity, whether consider the launching speed or not. The effect of the wave is random, and in this paper, the missile exit water from the trough of the wave, the missile has a excursion opposite the direction of the wave transmit. At last, the paper compared simulational results with practical experiments, the two results are consistency. As a result, the study by the method of the computational fluid dynamics and the technology of dynamic mesh during the process of missile launching is very accurate and can be applied into underwater trajectory and exit-water trajectory prediction and can be regards as references and gist.更多还原