Dynamical Relationship between the Propogation Speed and Surface Properties of Turbulent Premixed Flames

这项工作探索了湍流预混火焰的传播速度和表面特性之间可能的动态关系。火焰表面特性和传播速度都是在固定的燃烧器几何形状中直接测量的。最近几位研究人员的发现表明，湍流火焰表面积的增长速度大大低于观察到的火焰速度的增长速度，这对Damkohler关于火焰速度与褶皱火焰表面积成正比的假设提出了质疑。本研究解决了这种差异的来源，并对导致火焰速度增加的机制提供了基本的见解，因为火焰表面性质随着湍流的增加而变化。使用两种燃烧器几何形状：脉冲火焰流反应器，产生自由传播湍流预混火焰，同轴射流火焰燃烧器，稳定高湍流预混火焰。诊断包括高速摄影，火焰速度测量的条件激光多普勒测速仪，以及火焰表面特性的二维和三维成像。

Abstract - Lee This effort explores a possible dynamic relationship between the propagation speed and surface properties of turbulent premixed flames. Both flame surface properties and propagation speed are measured directly in fixed burner geometries. Recent findings of several researchers show that the rate of increase of the turbulent flame surface area is substantially lower than that for the observed flame speeds, casting doubt on Damkohler's assumption that the flame speed is proportional to the wrinkled flame surface area. This study addresses the source of this discrepancy and also gives fundamental insight into the mechanisms that cause the flame speed to increase as flame surface properties change with increasing turbulence. Two burner geometries are used: a pulsed-flame flow reactor that produces a freely propagating turbulent premixed flame, and a coaxial jet flame burner that stabilizes highly-turbulent premixed flames. Diagnostics include high-speed photography, conditional laser Doppler velocimetry for flame speed measurements, and two- and three-dimensional imaging for flame surface properties.