Simulations of Advanced Combustion Modes Using Detailed Chemistry Combined with Tabulation and Mechanism Reduction Techniques
Simulations of Advanced Combustion Modes Using Detailed Chemistry Combined with Tabulation and Mechanism Reduction Techniques
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DOI：
10.4271/2012-01-0145
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发表时间：
2012-05-01
影响因子：
1.2
通讯作者：
Jeanmart, Herve
中科院分区：
文献类型：
--
作者：
Contino, Francesco;Lucchini, Tommaso;Jeanmart, Herve
多维模型代表了当今用于模拟HCCI和柴油发动机中燃烧过程的综合工具。有多种方法可用于此目的，然而，广泛接受的是，当发动机以复杂的喷射策略或先进的燃烧模式运行时，详细的化学反应是获得满意结果的基本先决条件。然而，集成这样的机制通常会导致令人望而却步的计算cost.This本文提出了一个全面的方法，快速，高效的模拟内燃机燃烧，使用详细的化学。为此目的，技术列表的物种反应速率，并减少在飞行中的化学机制已经耦合。以这种方式，与使用这些机制相关的计算开销显著降低，因为表列的反应速率被重新用于具有相似组成的细胞，并且当有必要执行直接积分时，仅考虑相关的物种和反应集。它是一组使用OpenFOAM技术开发的用于IC发动机建模的库和应用。特别是，一个修改版本的原位自适应制表（ISAT）算法已开发的系统具有可变的温度和压力，和有向关系图（DRG）的方法已被用来减少在运行时的机制。验证已经进行了与HCCI和柴油机的情况下，都使用简化的情况下得到的结果进行比较，与TDAC，和一个详细的情况下，与实验数据进行验证。对于每个测试条件下，计算和实验数据之间的详细比较提供了沿着与使用直接集成相比，实现的加速因子。
Multi-dimensional models represent today consolidated tools to simulate the combustion process in HCCI and Diesel engines. Various approaches are available for this purpose, it is however widely accepted that detailed chemistry represents a fundamental prerequisite to obtain satisfactory results when the engine runs with complex injection strategies or advanced combustion modes. Yet, integrating such mechanisms generally results in prohibitive computational cost.This paper presents a comprehensive methodology for fast and efficient simulations of combustion in internal combustion engines using detailed chemistry. For this purpose, techniques to tabulate the species reaction rates and to reduce the chemical mechanisms on the fly have been coupled. In this way, the computational overheads related to the use of these mechanisms are significantly reduced since tabulated reaction rates are re-used for cells with similar compositions and, when it becomes necessary to perform direct integration, only the relevant set of species and reactions is taken into account.The proposed approach named tabulation of dynamic adaptive chemistry (TDAC) has been implemented in the Lib-ICE code, which is a set of libraries and applications for IC engine modeling developed using the OpenFOAM (R) technology. In particular, a modified version of the in-situ adaptive tabulation (ISAT) algorithm has been developed for systems with variable temperature and pressure, and the directed relation graph (DRG) method has been used to reduce the mechanism at run-time. The validation has been carried out with HCCI and Diesel cases both using a simplified case to compare the results obtained with and without TDAC, and a detailed case that is validated with experimental data. For each tested condition, a detailed comparison between computed and experimental data is provided along with the achieved speed-up factors compared to the use of direct-integration.