【作者】 刘永丰；

【导师】 王德明；

【作者基本信息】 哈尔滨工程大学 ， 动力机械及工程， 2013， 博士

【摘要】 内燃机作为当今社会能源消耗主体和环境污染来源受到了广大研究者的关注，数值模拟方法开辟了理论直接指导试验和设计的新途径，成为了内燃机燃烧过程和新产品开发的重要工具和有力补充。内燃机工作过程数值模拟的关键技术包括运动网格处理、喷雾模型、燃烧及化学反应机理以及缸内流场数值求解方法等。本文主要研究适用于内燃机缸内过程计算的数值模拟工具，研究动网格算法、燃油喷雾、混合气形成与燃烧的理论和数值方法。为了缸内工作过程计算效率的提高，编制了用于内燃机缸内过程的运动网格前处理器。实现了弹簧法、动态层法和增减网格算法处理网格运动，并提出了适用于缸内运动过程的合并分裂算法，在气缸内计算域变化过程中，将计算域网格进行多组同时合并或分裂。针对燃油喷雾过程关键的颗粒定位问题，提出了用于燃油喷雾的快速颗粒追踪算法。通过对单元面循环，判断两个时刻颗粒位置与单元面的关系来追踪颗粒所在单元。针对由于计算机误差造成的非平面问题，提出了虚拟三角化方法。对非结构多边形网格中单元面中不共面的网格面问题，人为地将多边形面划分为几个三角形，解决了非平面网格中颗粒穿出计算域的问题。编制了基于非结构网格有限体积法的两相反应流多维数值模拟软件。对气相采用Euler方法求解，采用有限体积法离散控制方程组，由SIMPLE算法求解压力速度耦合，而对液相采用离散液滴模型，通过Lagrange方法求解，考虑液相与气相之间的完全双向相互耦合。采用多维数值模拟软件单独研究了喷雾贯穿、单液滴蒸发、混合气形成、碰壁、燃烧过程，同时应用于缸内纯压缩和喷雾燃烧过程，通过与实验及商业软件对比验证了软件的可行性，表明所开发软件可用于内燃机缸内流动、喷雾和燃烧过程仿真和性能分析。更多还原

【Abstract】 As today’s main energy consumption and one of the main sources of environmental pollution, internalcombustion engines call for the attention of many researchers’ interests. The numerical analysis method hasopened up a new path to direct experiments and designs with theories. It is becoming a significant tool inanalyzing the combustion process of IC engines and new product research and development. The keyelements in numerical simulation of internal combustion engines consist of moving mesh generation, spraymodeling, combustion and chemical reaction modeling, and the cylinder flow field numerics. The mainobjective of the present thesis is the development of suitable numerical methods for internal combustionengine applications including moving mesh method, fuel spray, mixture formation and combustion.In order to improve the efficiency in analyzing in-cylinder process, a pre-processor for the movingmesh generation is developed. It consists of “spring method”,“dynamic layer method” and a refining andcoarsening grid algorithm. Also presented is a “merge-split” method, which is designed for variable domainof in-cylinder process by merging and splitting groups of computational cells at the same time.For locating the particles in a fuel spray, a fast particle tracking method is proposed. A particle’slocation is decided based on the relationship of its position vector and cell faces. A “virtual triangulationmethod” is developed to alleviate the non-planar problem caused by the numerical error. For non-planarcell faces associated with unstructured polyhedral meshes, the polygon of a surface is triangulated in orderto avoid “missing particles” associated with non-planar faces.A two-phase reacting flow modeling approach is developed applicable for unstructured grid finitevolume framework. The gas phase is solved by the Euler method. The governing equations are discretizedover finite volume of unstructured meshes. The pressure-velocity coupling is solved by SIMPLE algorithm.The Lagrangian discrete droplet method (DDM) is used for the liquid. Full two-way coupling betweenliquid phase and gas phase are considered.The developed technologies are implemented in an in-house software and is used to study the spraypenetration process, single-droplet evaporation, mixture formation and spray impingement on solid walls. Itis also applied for in-cylinder simulations with or without (pure compression) spray combustion. Validationof the models is accomplished through the comparison of experimental results with simulations. The workdemonstrated that the developed software can be used for the simulation and analysis of in-cylinder flow,spray and combustion process of internal combustion engines.更多还原