Study of the effect of turbulent mixing on chemical reaction in liquid

为了阐明湍流混合对液相化学反应的影响，本文从实验和计算两方面进行了研究。化学反应，简单但适合于光学测量，并且选择的是类型; A + B * R，B + R * S（1-萘酚（A）与重氮化的对氨基苯磺酸（B）在稀的水性碱性缓冲溶液中的偶氮偶联）。新研制的芯径为10 μ m的光纤探头可用于测量空间点上化学产品（R和S）的瞬时浓度。并装配了改进的多组分浓度测量系统。作为基础研究，本文对组分B进入组分A的湍流射流进行了研究。首先，使用购买的光纤型LDV系统测量平均速度和速度脉动均方根分布。其次，讨论化学产品R和S的浓度场的各种统计特性（平均值、波动rms ...更多信息 值、R和S之间的相关性、pdf等）作为对湍流管流混合过程的研究，本文对连续点源单组分在管壁上的扩散场进行了测量。管道中的湍流（内径D=100 mm，试验段长度2000 mm，雷诺数Re=U<@D2m@> D2 D/nu（] SY.simeq. [）20000，U<@D2m@>D2：最大平均速度）没有完全发展，但平均速度的径向分布在下游方向上几乎是自相似的。在数值模拟方面，采用随机傅立叶模态和随机飞行相结合的模型，研究了流体颗粒绕圆柱的扩散过程。用PDF方法对湍流中被动标量的分子混合模型进行了检验。为了将数值计算结果与实验结果进行比较，实验研究了球对网格湍流中羽流发展的扰动作用。通过分形分析，阐明了球体引起的流动畸变对分形维数的变化不起作用。本文还研究了同轴射流情况下两组分的混合过程。少

In order to clarify the effect of turbulent mixing on the chemical reaction occurring in liquid, the researches were performed both experimentally and computationally. Chemical reaction, simple but suited to optical measurement and selected is the type; A + B * R,B + R * S (the azo coupling of 1-naphthol (A) with diazotised sulfanilic acid (B) in dilute, aqueous, alkaline buffered solution). The optical fiber probe with the core diameter of 10 mum has been anew developed to measure the instantaneous concentrations of chemical products (R and S) at a spatial point. The improved concentration measuring system of multiple species was also fitted up. As the fundamental research,the turbulent jet of species B into species A was investigated. At first, the mean velocity and velocity fluctuation rms profiles were measured using the fiber type of LDV system purchased. Next, various statistical properties of the concentration fields of chemical products R and S (the mean value, fluctuation rms … More value, correlation between R and S, pdf, etc.) were investigated in detail.As the research on the mixing process in the turbulent pipe flow, the diffusion field of single species from the continuous point source on the wall was measured. The turbulence in the pipe (Inner diameter D=100 mm, the length of the test section 2000 mm, Reynolds number Re=U<@D2m@>D2D/nu (] SY.simeq.[) 20000, U<@D2m@>D2: maximum mean velocity) was not fully developed but the radial profile of the mean velocity is almost self-similar in the downstream direction. By examining the contours of the iso-mean concentration and iso-concentration fluctuation rms values, the spread of the plume was also clarified.With regards to the numerical simulation, the diffusion of fluid particle around a circular cylinder was investigated by the combined model of random Fourier modes and random flight. The molecular mixing models of the passive scalar in turbulent flow were also examined by the PDF method. To compare these numerical results with experiments, the disturbance effect of a sphere on the plume developed in grid-turbulence was investigated experimentally. From the fractal analysis, it is elucidated that the flow distortion due to the sphere is not effective to the change of the fractal dimension. The mixing process of two species in the case of coaxial jet was also examined. Less