• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Progress in Energy and Combustion Science >State-of-the-art in premixed combustion modeling using flamelet generated manifolds
【24h】

State-of-the-art in premixed combustion modeling using flamelet generated manifolds

机译：使用小火焰产生的歧管进行预混燃烧建模的最新技术

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

Flamelet based chemical reduction techniques are very promising methods for efficient and accurate modeling of premixed, flames. Over the years the Flamelet Generated Manifold (FGM) technique has been developed by the Combustion Technology Group of Eindhoven University of Technology. Current state-of-the-art of FGM for the modeling of premixed and partially-premixed flames is reviewed. The fundamental basis of FGM consists of a generalized description of the flame front in a (possibly moving) flame adapted coordinate system. The basic nature of the generalized flamelet model is that effects of strong stretch in turbulent flames are taken into account by resolving the detailed structure of flame stretch and curvature inside the flame front. The generalized flamelet model, which forms the basis on which FGM is built, is derived in Part I. To be able to validate numerical results of flames obtained with full chemistry and obtained from FGM, it is important that the generalized flamelet model is analyzed further. This is done by investigating the impact of strong stretch, curvature and preferential diffusion effects on the flame dynamics as described by the local mass burning rate. This so-called strong stretch theory is derived and analyzed in Part I, as well as multiple simplifications of it, to compare the strong stretch theory with existing stretch theories. The results compare well with numerical results for flames with thin reaction layers, but described by multiple-species transport and chemistry. This opens the way to use the generalized flamelet model as a firm basis for applying FGM in strongly stretched laminar and turbulent flames in Part II. The complete FGM model is derived first and the use of FGM in practice is reviewed. The FGM model is then validated by studying effects of flame stretch, heat loss, and changes in elements, as well as NO formation. The application to direct numerical simulations of turbulent flames is subsequently studied and validated using the strong stretch theory. It is shown that the generalized flamelet model still holds even in case of strong stretch and curvature effects, at least as long as the reaction layer is dominated by reaction and diffusion phenomena and not perturbed too much by stretch related perturbations. The FGM model then still performs very well with a low number of control variables. Turbulent flames with strong preferential diffusion effects can also be modeled efficiently with an FGM model using a single additional control variable for the changes in element mass fractions and enthalpy. Finally FGM is applied to the modeling of turbulent flames using LES and RANS flow solvers. For these cases, the flame front structure is not resolved anymore and unresolved terms need to be, modeled. A common approach to include unresolved turbulent fluctuations is the presumed probability density function (PDF) approach. The validity of this FGM-PDF approach is discussed for a few test cases with increasing level of complexity. (C) 2016 The Authors. Published by Elsevier Ltd.
机译：基于火焰的化学还原技术是用于高效，准确地对预混火焰建模的非常有前途的方法。多年来，埃因霍温科技大学燃烧技术小组已开发出火焰产生歧管（FGM）技术。回顾了用于预混和部分预混火焰建模的FGM的最新技术。 FGM的基本基础包括在（可能移动的）火焰适应坐标系中对火焰前沿的一般描述。广义小火焰模型的基本性质是，通过解决火焰前沿内部的火焰拉伸和曲率的详细结构，可以考虑湍流火焰中的强拉伸效应。在第一部分中得出了构成FGM的基础的广义小火焰模型。为了能够验证以全化学方法获得的火焰和从FGM获得的火焰的数值结果，重要的是进一步分析广义小火焰模型。这是通过调查强拉伸，曲率和优先扩散效应对火焰动力学的影响来完成的，如局部质量燃烧速率所述。在第一部分中，对这种所谓的强拉伸理论进行了推导和分析，并对其进行了多种简化，以将强拉伸理论与现有的拉伸理论进行比较。该结果与带有薄反应层的火焰的数值结果很好地比较，但是用多种物质的传输和化学描述。这为在第二部分中将FGM用于强拉伸层流和湍流火焰中的FGM奠定了坚实的基础。首先导出完整的FGM模型，并回顾FGM在实践中的使用。然后通过研究火焰拉伸，热损失，元素变化以及NO形成的影响来验证FGM模型。随后，使用强拉伸理论研究并验证了在湍流火焰直接数值模拟中的应用。结果表明，即使在强烈的拉伸和曲率效应的情况下，广义小火焰模型仍然成立，至少只要反应层受反应和扩散现象支配，并且不会因拉伸相关的扰动而受到太大干扰。然后，FGM模型在控制变量数量较少的情况下仍然表现良好。还可以使用FGM模型，使用单个附加控制变量对元素质量分数和焓的变化进行高效建模，从而对具有强烈优先扩散效应的湍流火焰进行高效建模。最后，使用LES和RANS流动求解器将FGM应用于湍流火焰的建模。对于这些情况，不再解决火焰前部结构，需要对未解决的术语进行建模。包含未解决的湍流波动的常见方法是假定的概率密度函数（PDF）方法。在一些复杂程度不断提高的测试案例中，讨论了这种FGM-PDF方法的有效性。 （C）2016作者。由Elsevier Ltd.发布

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