高温预混燃烧对湍流积分尺度影响的PIV研究

PIV Study on Effect of High Temperature Premixed Combustion on Turbulence Integral Scale

应用PIV(粒子成像测速技术)针对工业燃烧设备中以平焰燃烧为代表的高温预混燃烧过程,开展燃烧与非燃烧的冷、热态两种工况湍流流场的对比研究,揭示了高温预混燃烧对湍流涡旋积分尺度分布特性的影响。研究发现:伴随着动量和能量传输的燃烧过程,高温预混燃烧直接影响湍流涡旋结构的大小及分布。热态燃烧工况存在的最小积分尺度(12 mm)恰好是位于动量、能量强烈交换的火焰区,而速度和速度梯度很小的低速流动区存在较大积分尺度(23mm)。本研究为深入分析预混火焰传输机理打下基础。

In this paper,experiments have been performed to research the high temperature premixed combustion process of flat-flame combustion by PIV technique. Through the comparison of the turbulent flow field under two different conditions about cold non-burning and hot combustion,it reveals the effect of high temperature premixed combustion on distribution of turbulent vortex integral scale. The research shows that along with the momentum and energy transfer,the combustion process directly affect the size and distribution of the turbulent vortex structure,the minimum turbulence integral scale( 12 mm) of hot-state combustion condition is exactly flame zone which the momentum and energy exchange strongly. However,the flow area which speed and velocity gradient is very small exists large turbulence integral scale( 23 mm). The author thinks that this study would establish the foundation for the depth of the premixed flame transmission mechanism.