LCE: Numerical Study of Turbulence-Radiation Interactions in Reactive Flows

摘要 提案编号：CTS 9732223 主要研究者：M.谦虚 LCE：反应流中湍流-辐射相互作用的数值研究 辐射传热在大多数火灾以及商业燃烧应用中起着重要的作用，其效果通常与对流传热的效果具有相同的数量级，并且有时主导总传热速率。就像对流受到湍流的帮助一样，辐射也是如此，在存在化学反应的情况下，由于湍流的相互作用，辐射可能会增加数倍。然而，这样的湍流-辐射相互作用的计算是极其困难的，并且迄今为止在所有流行的CFD求解器中被忽略，或者通过任意降低预测的火焰温度以考虑湍流-辐射相互作用来经验性地处理。 一个有前途的方法占这些相互作用的概率密度函数（PDF）的方法。不幸的是，PDF方法在其目前的发展状态下有许多缺点，这妨碍了它在反应流中的使用。本研究的目的是进一步发展PDF方法，以解决尖锐的梯度，这存在于反应流，并模拟标量方程的相互作用。PDF方法的扩展将允许其包含在已建立的CFD代码中。新方法的准确性将通过与DNS计算和实验数据的比较来验证。 这项工作是由NSF/Sandia生命周期工程联合倡议资助的。

ABSTRACT Proposal Number: CTS 9732223 Principal Investigator: M. Modest LCE: Numerical Study of Turbulence-Radiation Interactions In Reactive Flows Radiative heat transfer plays an important role in most fires as well as in commercial combustion applications, with its effects usually being of the same order of magnitude as those of convective heat transfer, and sometimes dominating the overall heat transfer rates. In much the same way as convection is aided by turbulence, so is radiation, which in the presence of chemical reactions may increase several fold due to turbulence interactions. However, the calculation of such turbulence-radiation interactions is extremely difficult and has to date been neglected in all popular CFD solvers or is treated empirically by arbitrarily lowering the predicted flame temperatures to account for the turbulence-radiation interactions. A promising method for accounting for these interactions is the probability density function (PDF) approach. Unfortunately, the PDF method in its present state of development has a number of shortcomings, which preclude its use in reactive flows. The purpose of this research is to further develop the PDF method to resolve the sharp gradients, which exist in reacting flows, and to model the scalar equations for the interactions. The extension of the PDF method will permit it to be included in established CFD codes. The accuracy of the new method will be verified by comparison with DNS calculations and experimental data. This work is funded as part of the joint NSF/Sandia initiative in Life Cycle Engineering.