【作者】 宋桂霞；

【导师】 赵又群；

【作者基本信息】 南京航空航天大学 ， 车辆工程， 2008， 博士

【摘要】 两栖车辆的高速性能是衡量其性能指标之一,为了提高我国两栖车辆在水中的航速,对两栖车辆进行相关分析后,提出了减小车辆两栖车辆车轮的阻力来提高速度的策略,并设计了车轮收起方案。车轮收放方案综合考虑了车辆的空间布置、收起状态、运动干涉以及陆上行驶的安全性,设计了合理的收起方式、定位方式,以及陆上行驶车辆车轮收放功能失效,使车轮在水中收起时能平稳快捷,车辆在陆上行驶时安全稳定。车轮收起的力由液压系统产生。设计了完整的液压系统回路,并通过对液压元件的参数设置和仿真,检验了液压系统的稳定性。由导轨约束减振器和螺旋弹簧的定位,确定了车辆陆上行驶的安全稳定性。通过优化悬架结构参数,使车轮收起后的状态能使附件阻力充分减小。驱动半轴以及横向稳定杆与下横臂之间采用合适的连接形式,避免收起车轮时的运动干涉,使车轮收放能顺利进行。由压力感测器感知车辆陆上和入水后压力的变化,来控制车轮收起功能是否工作,以保证车辆陆上行驶的安全。利用Fluent对车轮收起前后的车辆进行了流体仿真,对比分析了车轮收起前后阻力的变化。结合车辆实际运行环境,模型采用了水气两相流进行分析。根据车辆外型断面变化剧烈、扰流情况复杂的特点,在对计算区域划分网格时,采用了内部为非结构网格、外部为结构网格的混合网格划分方法,以充分捕捉流场。为了加快计算速度,采用了并行计算方法。最后针对车首上水严重的现象,根据仿生学原理设计了一种新的防浪板类型,并通过仿真,对比分析了两种防浪板对水流的导流情况。对悬架结构优化前后的整车进行了仿真,分析了悬架变动前后车辆性能的变化。首先通过对比悬架变动前的整车动力学模型的仿真结果和实车试验结果,验证模型的正确性,然后对悬架优化前后的整车虚拟样机进行操纵稳定性和行驶平顺性的仿真分析,通过改变悬架优化后整车的一些参数,使其仍基本保持原车的性能。更多还原

【Abstract】 High speed is one of the indexes to estimate amphibious vehicle`s performance. In order to advance the speed of amphibious vehicle of China when sailing in water, the strategy of reducing wheels` resistance and increasing speed is proposed, and design a scheme of retracting and deploying wheels.The scheme takes into account vehicle`s space configuration, wheels` deployed state, movement intervene, and security when running on land synthetically. The retracted mode, orientation mode, and prevent wheels from being retracted by mistake when vehicle running on land are all calculated, so wheels can be retracted smoothly and fleetly, and vehicle can run security and stability. The force that retracts wheels is supplied by hydraulic system; design the hydraulic circuit system, by setting the parameters of the hydraulic components and simulating to test the stability of hydraulic system. Displacements of spring and absorber upper ends are restricted by guide way to ensure the security and stability of vehicle. Resistance is reduced caused by wheels as much as possible by optimizeing suspension configuration parameter. Drive shafts and anti-roll bar with low arms are adopted appropriate joint to avoid movement intervene when retracting wheels, and keep wheels` retract and deploy successfully. The change of pressure is received by pressure detector after vehicle into water to control wheels retracting function, and ensure vehicle security running on land.Resistance variety of amphibious vehicles in wheels` retracting and deploying are analyzed using Fluent. Conbine with vehicle`s factual work condition, numerical simulation is carried through by VOF multiphase. Because the bodywork configuration is complexity, and turbulent was severity around it, flows are compartmentalized by using mixed grid to track flow field fully, and using parallel computation to enhance computing speed. In order to improve water loading of amphibious vehicle head, a new anti-wave board shape is designed based on bionics, and using simulating to analyze diversion water function.Simulation is carried through to contrast performance change when suspension is optimization. Firstly, by comparing the simulation results with real vehicle test results of previous vehicle to test the validity of multi-body dynamics model; secondly, simulate the handling stability and riding of previous vehicle and vehicle which suspension optimized, and by changing some parameters of vehicle that suspension optimized, let it remain previous vehicle`s performance basically.更多还原