(1. 南京工業(yè)大學(xué)機(jī)械與動(dòng)力工程學(xué)院，南京 210009；
2. 武漢工程大學(xué)機(jī)電工程學(xué)院，武漢 430073；
3. 武漢工程大學(xué)化工與制藥學(xué)院，武漢 430073)
摘 要: 在撞擊流技術(shù)制備納米銅粉的實(shí)驗(yàn)反應(yīng)體系中，粒徑的分布規(guī)律與流場(chǎng)混合尺度存在某種聯(lián)系。采用數(shù)值計(jì)算方法，從流場(chǎng)多尺度角度開(kāi)展液體連續(xù)相撞擊流反應(yīng)器(LISR)強(qiáng)化制備過(guò)程分析。結(jié)果表明：大尺度流體對(duì)流由槳葉旋轉(zhuǎn)帶動(dòng)，中等尺度湍流擴(kuò)散強(qiáng)度與湍黏度和速度梯度關(guān)聯(lián)，小尺度流體黏性擴(kuò)散與中等尺度湍流擴(kuò)散類(lèi)似；LISR為制備納米銅粉反應(yīng)體系提供一個(gè)強(qiáng)烈壓力波動(dòng)區(qū)，其微觀狀態(tài)下的反應(yīng)體系隨著壓力波動(dòng)區(qū)能量的傳遞和轉(zhuǎn)換得以迅速實(shí)現(xiàn)，并顯著促進(jìn)制備納米銅粉反應(yīng)過(guò)程的進(jìn)行；LISR中湍黏擴(kuò)散作用顯著，能高效促進(jìn)流體更加均勻，有利于制備納米銅粉反應(yīng)體系。上述過(guò)程流場(chǎng)的多尺度分析，對(duì)后期撞擊流技術(shù)制備納米銅粉的實(shí)驗(yàn)反應(yīng)體系工藝優(yōu)化具有指導(dǎo)意義。
關(guān)鍵字: 撞擊流反應(yīng)器；納米銅粉；流場(chǎng)；多尺度分析；數(shù)值模擬
（1. School of Mechanical and Power Engineering, Nanjing Technology University, Nanjing 210009, China;
2. School of Mechanical and Electrical Engineering, Wuhan Institute of Technology, Wuhan 430073, China;
3.School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073, China）
Abstract:In the experiment system of preparing nano-copper powder in impinging stream reactor, there is an association between particle size distribution and flow mixing scale. The strengthened preparation process in liquid-continuous impinging streams reactor (LIRS) was analyzed by numerical computation from multi-scale standpoint. The results show that the large-scale convection is driven by rotating blades, the medium-scale turbulence diffusion intensity and turbulent viscosity are associated with velocity gradient，and small-scale viscosity diffusion is similar with that of medium-scale turbulent diffusion. LISR provides the reaction system with a strong pressure fluctuation zone, in which the micro reaction system can quickly be realized and promoted with the energy transfer and conversion. The remarkable turbulent viscous diffusion can effectively accelerate the fluid more uniform and be conducive to the reaction system. The multi-scale analysis of the flow field above has guiding significance for the optimization of the latter preparing of the impinging stream technology of nano-copper powder reaction system.
Key words: impinging stream reactor; nanometer copper powder; flow field; multi scale analysis ;numerical simulation
