散斑能见度光谱法测量筒仓内颗粒流的颗粒温度  

Measurement of granular temperature during silo flow by speckle visibility spectroscopy

作　　者：陈泉 郑泽希 李然[1,3] 孙其诚[4] 杨晖[1] CHEN Quan;ZHENG Zexi;LI Ran;SUN Qicheng;YANG Hui(School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;School of Mechanical Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;School of Medical Instrument and Food Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093 [2]上海理工大学机械工程学院,上海200093 [3]上海理工大学医疗器械与食品学院,上海200093 [4]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《化工学报》2022年第6期2603-2611,共9页CIESC Journal

基　　金：国家自然科学基金项目(91634202,11972212,11902190,12072200,12002213);上海市自然科学基金项目(20ZR1438800);上海市“科技创新行动计划”启明星培育(扬帆专项)项目(22YF1429700)。

摘　　要：筒仓内颗粒流在化工生产中广泛应用,准确描述颗粒流的动力学规律对于调控化工反应过程中的混合和传输效率极为重要。颗粒温度是影响颗粒流的重要参数之一,为此搭建了基于线阵CCD相机的散斑能见度光谱测量装置,选取均值粒径分别为0.94和1.55 mm的球形颗粒进行实验。通过测量卸料过程中筒仓内颗粒流的时变颗粒温度,发现了离散颗粒运动在介尺度条件下具有稳定性。进一步,对比两种粒径颗粒的颗粒温度值,观察到稳态流动中大粒径颗粒具有更高的能量耗散,从而建立了宏观质量流率与介观颗粒温度之间的联系。通过分析筒仓内颗粒温度场的分布特征,发现了孔口附近的离散颗粒存在定向有序的运动。最后,根据筒仓内颗粒流堵塞过程中的颗粒温度变化曲线,揭示了颗粒流堵塞的弛豫变化规律。实验结果揭示的筒仓内颗粒流的运动规律,为完善化工生产中颗粒材料的存储与运输提供了参考数据。Granular flow in silos is widely used in chemical reactions.Accurately grasping the dynamic law of granular flow is extremely important for regulating the mixing and transmission efficiency in chemical reaction process.Granular temperature is one of the important parameters affecting granular flow.In this paper,a speckle visibility spectroscopy measurement device based on linear CCD camera is built,and spherical particles with mean particle sizes of 0.94 and 1.55 mm were selected.By measuring the time-varying granular temperature during silo flow,it was found that the discrete particle motion is stable under mesoscale conditions.Further,comparing the granular temperature values of the two particle sizes,it is observed that the larger particle size has higher energy dissipation in the steady-state flow,so the relationship between the macro mass flow rate and the mesoscopic granular temperature is established.In addition,by analyzing the distribution characteristics of the particle temperature field in the silo,it is found that the discrete particles near the orifice have directional and orderly motion.Finally,according to the curve of granular temperature during the jamming in silos.the relaxation change law of clogging is revealed.The experimental results reveal the law of granular flow in the silo,which provides reference data for improving the storage and transportation of granular material in chemical production.

关 键 词：颗粒流 动力学 介尺度 颗粒温度 堵塞 

分 类 号：TB133[机械工程—光学工程]