• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Combustion and Flame >Conditional moment closure; Autoignition; Turbulent; SprayzSimulations of spray autoignition and flame establishment with two-dimensional CMC
【24h】

Conditional moment closure; Autoignition; Turbulent; SprayzSimulations of spray autoignition and flame establishment with two-dimensional CMC

机译：有条件的力矩闭合；自燃；湍流Sprayz使用二维CMC模拟喷雾自燃和火焰建立

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The unsteady two-dimensional conditional moment closure (CMC) model with first-order closure of the chemistry and supplied with standard models for the conditional convection and turbulent diffusion terms has been interfaced with a commercial engine CFD code and analyzed with two numerical methods, an "exact" calculation with the method of lines and a faster fractional-step method. The aim was to examine the sensitivity of the predictions to the operator splitting errors and to identify the extent to which spatial transport terms are important for spray autoignition problems. Despite the underlying simplifications, solution of the full CMC equations allows a single model to be used for the autoignition, flame propagation ("premixed mode"), and diffusion flame mode of diesel combustion, which makes CMC a good candidate model for practical engine calculations. It was found that (ⅰ) the conditional averages have significant spatial gradients before ignition and during the premixed mode and (ⅱ) that the inclusion of physical-space transport affects the calculation of the autoignition delay time, both of which suggest that volume-averaged CMC approaches may be inappropriate for diesel-like problems. A balance of terms in the CMC equation before and after autoignition shows the relative magnitude of spatial transport and allows conjectures on the structure of the premixed phase of diesel combustion. Very good agreement with available experimental data is found concerning ignition delays and the effect of background air turbulence on them.
机译：非稳态二维条件矩闭合（CMC）模型（具有化学物质的一阶闭合）以及条件对流和湍流扩散项的标准模型已提供给商用发动机CFD代码，并使用两种数值方法进行了分析：使用线法和更快的分数步法进行“精确”计算。目的是检查预测对操作员分裂误差的敏感性，并确定空间运输术语对喷雾自燃问题的重要程度。尽管有潜在的简化，但完整的CMC方程式的解决方案仍允许将单个模型用于柴油机的自动点火，火焰传播（“预混合模式”）和扩散火焰模式，这使CMC成为进行实际发动机计算的良好候选模型。 。发现（ⅰ）点火前和预混模式期间的条件平均值具有明显的空间梯度，并且（ⅱ）包含物理空间传输会影响自燃延迟时间的计算，这两者均表明了体积平均CMC方法可能不适用于类似柴油的问题。自燃前后，CMC方程中的项平衡显示了空间传输的相对量，并允许对柴油机燃烧预混相的结构进行推测。关于点火延迟和背景空气湍流对其的影响，发现与可用的实验数据非常吻合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号