Research Initiation Award: Radiation/Turbulence Interactions in Flows with Participating Media

提出的研究计划的目的是开发新的整体计算方案，采用谱法精确和有效地解决具有辐射传递的流体流动。这将极大地扩展可以用数值方法研究的辐射问题的范畴。例如，振荡或弱湍流可以在没有近似的模拟中完全解决，即可以获得控制方程精确形式的数值解。具体来说，控制方程（Navier-Stokes，能量守恒和辐射传递方程）将被离散化，并通过使用有效的伪谱搭配和tau算法将傅里叶级数和切比雪夫多项式作为基展开函数进行求解。为了开发和验证这些方案，并评估其性能和准确性，新模型将应用于辐射和自然对流在同心水平圆柱体之间有参与介质的流动中的组合问题。还将进行实验，为这一目的提供定量信息。全息干涉仪将用于提供温度场的测量，激光多普勒测速仪（LDV）将用于测量波动速度场。选择同心圆柱体的几何形状是因为它的结构相对简单，并且在自然对流情况下振荡流动和向湍流过渡的充分记录的存在。研究计划的成功完成将极大地提高我们进行工程辐射传热分析的能力。

The objective of the proposed research program is to develop new overall computational schemes which employ spectral methods for the accurate and efficient solution of fluid flows with radiative transfer. This will significantly extend the class of radiation problems that may be studied numerically. For example, oscillating or weakly turbulent flows could be fully resolved in a simulation without approximation, i.e. numerical solutions to the exact forms of the governing equations could be obtained. Specifically, the governing equations (Navier-Stokes, energy conservation, and radiative transfer equations) will be discretized and solved by employing Fourier series and Chebyshev polynomials as basis expansion functions with efficient pseudospectral collocation and tau algorithms. To develop and validate these schemes, and to evaluate their performance and accuracy, the new models will be applied to the problem of combined radiation and natural convection in flows with participating media between concentric, horizontal cylinders. Experiments will also be performed to provide quantitative information for this purpose. A holographic interferometer will be used to provide measurements of the temperature field, and Laser Doppler Velocimetry (LDV) will be used for measurements of the fluctuating velocity field. The concentric cylinder geometry is chosen due to its relatively simple configuration and the well-documented existence of oscillating flows and transition to turbulence in the natural convection case. Successful completion of the proposed research program will dramatically improve our ability to perform engineering radiation heat transfer analyses.