【作者】 孙磊；

【导师】 许厚谦；

【作者基本信息】 南京理工大学 ， 工程热物理， 2006， 硕士

【摘要】 本文对含有动边界的膛口燃气射流场(膛口流场)进行了数值模拟，并在模型中加入了化学反应，模拟了膛口焰的产生和发展过程。本文以7.62mm步枪和12.7mm机枪为例进行了计算，主要研究内容如下： 1) 在计算中加入了湍流模型，考虑了粘性对膛口流场的影响，得到了更加真实的膛口流场； 2) 使用动网格方法，在计算中考虑了运动弹丸对膛口流场的影响，以7.62mm步枪为例，模拟了没有初始流场影响的含运动弹丸的膛口流场，并将计算结果与实验照片比较，二者大致吻合； 3) 在计算模型中加入了膛管这一部分，以12.7mm机枪为例，获得了其初始流场，并在此基础上对膛口流场进行了数值模拟，得到了与实验相吻合的计算结果； 4) 细致的分析了弹丸在膛口流场中的受力情况，拟合了弹丸的受力公式，计算出弹丸的增速； 5) 在正确模拟膛口流场的基础上考虑火药气体的二次燃烧，分别模拟了无初始流场影响的7.62mm步枪和有初始流场影响的12.7mm机枪的膛口焰，并对燃烧过程中化学反应组分的变化作了描述。更多还原

【Abstract】 This thesis simulates the muzzle exhaust flow field and muzzle flash of 7.62mm rifle and 12.7mm scatter-gun including movable bullet. The following results are obtained:1. Turbulence model is added in the computation, so the influence of viscosity is considered, and more actual results are got.2. Dynamic mesh method is used to solve the mesh problem when bullet moves. Exampled for 7.62mm rifle, muzzle exhaust flow field without precursor flow field is simulated. The results are compared well with experimental photograph.3. Calculate the movement of bullet in the tube to get the precursor flow field, and exampled for 12.7mm scatter-gun, muzzle exhaust flow filed with precursor flow field is simulated. The results are also compared well with experimental photograph.4. The force on the bullet when it moves in the muzzle exhaust flow field is analyzed clearly, and then a force formulation is set up, so how much the bullet speed up can be calculated.5. Based on the accurate simulation of muzzle exhaust flow field, chemical reaction of propellant gas is considered. The muzzle flash of 7.62mm rifle without precursor flow field and 12. 7mm scatter-gun with precursor flow field is simulated, and the change of chemical component in the reaction is described.更多还原