Measurement of scalar fluctuations in micro-scale of turbulence in the case of diffusivity much less than viscosity

本研究发展了三种标量测量技术，以便从实验上了解平均浓度变化，特别是扩散系数远小于运动粘度时湍流中的标量混合。单点/两点测量揭示了标量谱理论的正确性。面阵/线扫描相机测量技术已被用来研究宏观/微观混合，并已被湍流混合射流所验证。

In this study, three types of scalar measurement technique have been developed, in order to understand experimentally the scalar mixing in turbulence under mean concentration variation, in particular, diffusivity being much less than kinematic viscosity. Single/two-point measurement reveal the validity of theory for scalar spectrum. Measurement technique using area/line-scan cameras has been developed for investigating macro-/micro-scopic mixing and has been verified by turbulent mixing jet.