Scattering and Excitation of Acoustic Waves by Turbulent Flames

本文从理论上研究了湍流火焰对声波的激发和散射。具体地说，它研究了不同粗糙度的移动的、曲折的火焰锋面的声辐射特性。它还研究了如何将散射和激发波的空间和时间特征用作湍流火焰锋面的诊断。本研究采用耦合积分方程法分析声场。完整的解需要两个这样的方程的解，这两个方程描述火焰上游和下游的场，它们由质量、动量和能量守恒条件耦合。在某些极限情况下得到解析解，而对于解析难以处理的情况则使用数值边界元方法。这项工作是对同一现象的实验研究的补充，该研究由首席调查员的职业奖励支持。

This is a theoretical investigation of the excitation and scattering of acoustic waves by turbulent flames. Specifically, it examines the acoustic radiation characteristics of moving, convoluted flame fronts of various scales of roughness. It also looks at how the spatial and temporal characteristics of the scattered and excited waves can be used as a diagnostic of turbulent flame fronts. The study uses a coupled integral equation approach to analyze the acoustic field. The complete solution requires the solution of two such equations, describing the field upstream and downstream of the flame, that are coupled by mass, momentum, and energy conservation conditions. Analytical solutions are obtained in certain limiting cases, while a numerical boundary-element approach is used for analytically intractable cases. This effort complements an experimental study of the same phenomena supported by a CAREER award to the principal investigator.