【作者】 谭罡风；

【导师】 过学迅；

【作者基本信息】 武汉理工大学 ， 车辆工程， 2011， 博士

【摘要】 重型汽车在经济和社会发展中的作用日渐突出,已经成为公路货物运输的主力。在山区公路行驶的重型汽车和一些特种重型汽车,动力传动系的热负荷大,其工作温度区间直接关系到整车的使用稳定性,间接影响到整车的动力性和燃油经济性；散热系统的控制方式,与发动机的寄生损失紧密关联。本文研究重型汽车动力系和传动系的热管理系统,主要工作包括：1.建立了动力传动系动力学模型并确定了其热管理系统方案。建立了动力系热源与热管理部件的传热计算模型。将传动系统热源模型进行了等效处理；采用工程流体力学的方法,建立了传动系统“油-空”散热器的三维热分析模型。2.由动力传动系统仿真,为其热管理系统仿真提供边界条件。通过发动机热管理系统一维仿真,研究了其热管理系统的稳定性和热管理部件的性能特性。采用三维流体仿真分析,获得传动系热管理系统“油-空”散热器整体的传热特性和空气侧流阻特性,并得到传动系热管理系统仿真结果。3.进行了动力系和传动系的热管理台架试验。介绍了热管理试验的内容、方法,对试验数据进行了分析与处理。将试验数据与仿真结果进行对比,验证了动力系和传动系仿真模型的有效性。4.建立了完整的动力传动系统热管理仿真模型。基于整车行驶工况,将传统机械驱动方式与独立风扇驱动方式相比较。结果显示,采用独立风扇驱动方式的热管理系统,热源工作温度相对稳定,发动机寄生功率损失明显降低。本文的创新点如下：1.传动系统的主要热源液力缓速器,内部流态复杂,且在整个工况下均处于非全充液状态,从计算机资源和两相流的理论发展上看,采用流体力学的方式研究其生热机理并不可行,本研究转换思路建立了缓速器的等效热计算模型。2.采用三维流体力学的方法研究“油-空”散热器的热力学特性。本研究采用服务器能处理的最大网格数量的散热器翅片单元为研究点,在充分利用计算机资源的同时,实现散热器热力学特性的研究。3.采用行驶工况的方法,从系统角度,在一维整车热管理系统模型中,考虑不同工况条件下各动力传动部件的相互耦合,以热源的温度波动和系统能耗为目标,研究重型汽车动力传动系热管理系统的控制方法。更多还原

【Abstract】 The economic benefit of the heavy truck is gradually outstanding in the national economy and the heavy truck has been the main force in the highway transportation. The heavy truck which often drives in the mountainous area and the one having special missions has heavy thermal load in the vehicle’s driveline. The working temperature region of the driveline is directly related to the vehicle driving stability, and affects the vehicle dynamic performance and fuel economy as well. The heat reject control mode is closly related to the parasitic loss of the power source.The thermal research on special vehicle driveline includes:1. The driveline dynamical model is built and the construction for the thermal management system is fixed. The detailed engine thermal management model is built. The heat source of the transmission is processed equivalently. And the engineering fluid mechanics (EFD) is adopted to set up the 3-D thermal model of the oil-to-air cooler.2. The driveline dynamical simulation provides the boundary conditions for the driveline thermal management system. The stability of the engine thermal management system and the performance characteristics of its components are considered based on the unidimensional simulation of the engine thermal management system. According to the 3-D fluid analysis, the heat-transfer characters of the oil cooler and the flow resistance of its air-side are obtained. The results of the simulation in transmission thermal management system are found out.3. The engine and transmission thermal management experiment are carried out respectively. The contents, methods of the two experiments are introduced, and the test data are processed and analyzed. The comparisions of the simulation result and test data verify the validity of the simulation models of the driveline thermal managenment system.4. The complete driveline thermal management model is built. On the basis of the same whole vehicle driving cycle, comparing to the traditional mechanical-drive system, the independent-drive system makes the working temperature of the heat source more stable. Meanwhile the parasitic power caused by the radiator fan is decreased markedly on the condition that the heat reject requirement of the heat source is satisfied.The main innovation points include:1. The heavy truck driveline thermal calculation platform is developed. The driveline thermal characteristics are obtained based on the parameters of the main driveline components and the whole vehicle. The radiator overall dimension, which ascertains underhood layout is calculated according to the design proposal of the thermal management system.2. The engineering fluid mechanics (EFD) is adopted to set up the 3-D thermal model of the oil-to-air cooler. The engry point is the radiator’s most feasible fin unit which contains the most amount of the calculate cells that the server could process. The research on the thermal characteristic of the cooler is implemented while the computer resource is made full use of.3. The heavy vehicle driving cycle for the thermal management system is developed. The intercoupling of the driveline conponents in different working condition is considered in the driveline thermal management model. The control methed of the driveline thermal management system is studied for the aims of reducing the working temperature fluctuation of the heat source and the power consumption for the thermal management.更多还原