【作者】 陈志伟；

【导师】 郑津洋；

【作者基本信息】 浙江大学 ， 化工过程机械， 2006， 硕士

【摘要】 本文以全国锅炉压力容器标准化技术委员会《液化气体运输车》标准的编制工作为依托,以盛装液体介质的移动式压力容器为研究对象,通过数值模拟方法对容器中的介质晃动进行了研究,主要探讨带自由面的液体晃动数值模拟方法,初步研究液体介质晃动对刚性壁面的冲击作用以及容器内的防晃装置设置情况。主要工作如下: (1)对国内几家生产汽车罐车的主要厂家进行了调研。厂家反映《液化气体汽车罐车安全监察规程》中关于汽车罐车内部防波板设置规定不合理,规定的防波空间过小,致使罐车内防波板数量过多;在役罐车防波板脱落问题比较严重,并对防波板的防波效果提出了质疑。通过对这些厂家罐车产品的调研,了解了多种防波板的型式以及防波板与罐体的连接方法。 (2)确定了数值模拟模型和方法。选用有限体积法和简化的刚体模型,借助FLUENT软件,对充有粘性不可压介质的立式圆柱形容器和卧式柱形罐车内部介质晃动进行了模拟,获得了液体晃动的固有频率,通过与已有的解析解、实验值和部分数值解进行比较验证,确定了VOF方法用于自由液面的定义,标准κ-ε湍流模型作为湍流计算模型,并确定了计算中模型参数的选择范围,还确定了汽车罐车减速运动介质晃动的等效力学模型,为进一步研究探索了方法和方向。 (3)纵向晃动数值模拟。对汽车罐车制动减速过程中内部介质纵向晃动进行了模拟,主要研究了制动加速度、充装系数和防波板设置情况与容器受到的介质作用力之间的关系。结果表明罐体制动过程中介质对封头的作用力远大于罐车静止后介质自由晃动时介质对封头的作用力;充装系数较大时,介质对罐体的冲击作用力能更迅速达到稳定值;防波板可以使罐车制动过程中介质对罐体的作用力在时间域上更趋于平稳。 (4)横向晃动数值模拟。对汽车罐车转弯时内部介质横向晃动进行了数值模拟,研究了充装系数与侧翻力、侧翻力矩的关系,确定了防止侧翻较合理的充装系数,其值应大于0.80。更多还原

【Abstract】 Based on establishment of the standard of "liquefied gas tanker" in CSCBPV (China Standardization Committee on Boilers and Pressure Vessels), the research of transportable pressure vessel is carried out and the liquid sloshing in the transportable pressure vessel is simulated by numerical method in this thesis. The numerical method of liquid sloshing with three-dimensional free surface is discussed. The force which the sloshing liquid acts on the rigid wall of the vessel is measured, and the baffles in vessel which prevent liquid sloshing are studied in this thesis. The main research results are as follows:(1) Investigating several factories which produce cargo tanks. The engineers of these factories consider that the provisions of the baffles in cargo tanks aren’t reasonable; the volume between two close baffles is small, then the number of baffles is too large; the baffles always fall off. The engineers even disbelieve the baffles capacity of preventing liquid sloshing. By this investigation, the shapes of the baffles and the forms of connection are obtained.(2) Establishing model and method of sloshing simulation. The liquid in the vessel is assumed viscous and incompressible, and the vessel and baffles are assumed rigid. The numerical simulation of three-dimensional liquid sloshing in vertical and horizontal cylindrical tanks is carried out by the software of FLUENT. The sloshing natural frequency is compared and validated with analytic solution, experimental results and numerical results. The liquid sloshing is also simulated when vessel is horizontally decelerated. Then, the mechanical model, the simulation method of the fluid and the turbulence model are selected in reason.(3) Simulation of liquid longitudinal sloshing. The cargo tank is a typical transportable pressure vessel, and liquid sloshing has a serious effect on its safety while driving. The liquid longitudinal sloshing in the cargo tank is simulated successfully at different speed, from steady movement, deceleration, until stillness. The simulation of sloshing in vessel with transverse rigid baffles is carried out, and the force on the baffles and heads is measured and recorded. It contributes to the improvement of baffle form and preventing baffles from falling off.(4) Simulation of liquid horizontal sloshing. The simulation of liquid sloshing is carried out when the tank is turning. The sloshing force on shell arouses overturning moment, and the possibility of tanker overturning increases. The centrifugal acceleration and character of liquid are assumed to be constant, and the overturning moment is related to ratio of filling coefficient.更多还原