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Radiative properties and radiative heat transfer calculations for high temperature combustion gases.

机译：高温燃烧气体的辐射特性和辐射传热计算。

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摘要

Combustion in fires and in commercial combustion systems produces substantial amounts of heat and locally high temperatures, making radiation an important mode of heat transfer for most combustion applications. Unfortunately, spectral modeling of molecular gas radiation remains a difficult task to this day due to inadequate knowledge of radiative properties of important participating gases and lack of efficient and accurate radiation models.; A highly successful global model, the Full-Spectrum k-distribution (FSK) model, was developed in this thesis, extending the concept of narrow band k-distributions to the entire spectrum by introducing a fractional Planck function. The treatment of nonhomogeneous media was comprehensively discussed and optimized, concentrating on the approach of Correlated (Full-Spectrum Correlated k-Distribution Model) and/or Scaled absorption coefficients (Full-Spectrum Scaled k-Distribution Model).; For strongly nonhomogeneous media, the Full-Spectrum k-distribution model was extended to multi-scale and multi-group gases. In the multi-scale approach (MSFSK), the spectral lines of individual gases were broken up into different scales according to their lower level energies, or different species in a gas mixture were simply separated. An approximation was introduced to account for the overlap of the absorption coefficient between different scales. In contrast, in the multi-group approach (MGFSK), spectral locations were sorted into several spectral groups, according to their absorption coefficient dependence on (partial) pressure and temperature, resulting in no overlap between different groups.; A thorough investigation of the absorption coefficient dependence on temperature and partial pressure was done for the two most important combustion gases, CO2 and H2O. Based on the Multi-Group approach, state-of-the-art databases were constructed, making it possible to achieve any desired accuracy for the radiative heat transfer calculations in combustion systems, at the price of just a few spectral calculations.
机译：火灾和商业燃烧系统中的燃烧会产生大量的热量和局部高温，从而使辐射成为大多数燃烧应用中重要的热传递方式。不幸的是，由于对重要的参与气体的辐射特性了解不足，并且缺乏有效而准确的辐射模型，因此分子气体辐射的光谱建模至今仍是一项艰巨的任务。本文开发了一个非常成功的全局模型，即全谱 k -分布（FSK）模型，将窄带 k -分布的概念扩展到整个通过引入分数普朗克函数获得频谱。对非均匀介质的处理进行了全面的讨论和优化，着重于相关方法（全光谱相关 k -分布模型）和/或比例吸收系数（全光谱比例 k < / italic>-分布模型）。对于强非均匀介质，全谱 k 分布模型已扩展到多尺度和多组气体。在多尺度方法（MSFSK）中，根据每种气体的较低能级将其光谱线分解为不同的尺度，或者将气体混合物中的不同物质简单地分离出来。引入了一个近似值以说明不同比例之间吸收系数的重叠。相比之下，在多组方法（MGFSK）中，根据光谱吸收位置对（部分）压力和温度的依赖性，将光谱位置分为几个光谱组，从而使不同的组之间没有重叠。对两种最重要的燃烧气体CO 2 和H 2 O的吸收系数对温度和分压的依赖性进行了深入研究。基于多组方法，构建了最先进的数据库，从而使燃烧系统中的辐射传热计算可以达到任何所需的精度，而只需几个频谱计算即可。

著录项

  • 作者

    Zhang, Hongmei.;

  • 作者单位

    The Pennsylvania State University.;

  • 授予单位 The Pennsylvania State University.;
  • 学科 Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 2002
  • 页码 150 p.
  • 总页数 150
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 机械、仪表工业;
  • 关键词

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