基于整场离散的气缸盖热流固多物理场耦合状态数值模拟

针对柴油机气缸盖工作状态数值模拟的复杂性及高耗时性,提出一种基于整场离散的高温燃气(热)、冷却液(流)、机械负荷(固)之间多物理场耦合分析方法.首先分析了热-流-固耦合的基本原理及关键问题,构建了气缸盖流固耦合传热的物理模型及有限元模型,采用整场离散法对气缸盖流固传热状态进行了耦合求解,得到了气缸盖的温度场,并在此基础上进一步与机械负荷产生的应力场进行耦合求解,得到多场共同作用下气缸盖的温度场及应力场,并分析了产生原因,实现了柴油机气缸盖热-流-固多物理场的耦合状态分析.结果表明:文中研究通过对流固耦合传热区域建立控制方程,使得传热交界面成了求解区域的内部,简化了热-流-固边界区域之间的反复迭代,相比于传统的分区计算-边界耦合法,提高了计算效率. 

Numerical Simulation Based Overall Discrete Method for Thermo-Fluid-Solid Coupling of Cylinder Head

As for the complex and high consuming in numerical simulations on working condition of cylinder head in diesel engine, a new numerical analysis method was proposed adopting thermo (high temperature gas), fluid (coolant liquid) and solid (mechanical load) multi-physics field coupling method based overall discrete. Analyzing the fundamental and key issues of thermo-fluid-solid coupling, the physical models and finite element model were presented for fluid-solid coupling and heat transferring to get the temperature field distributions of diesel engine cylinder head based overall discrete method. On this basis, the stress field produced from mechanical load was coupled solved, getting the spread of the temperature and stress field on cylinder head under multi-field effects. Based the possible causes analysis, some numerical simulations about thermo-fluid-solid multi-physics field coupling state were given. The results show that, the established governing equation in integral solution method can make the heat transfer boundary be in the solve region and omit iterative between thermo-fluid-solid regions. And the simulation efficiency is improved compared with tradition computing and boundary coupling method.