摘要
曳力系数是表征气固相互作用的基础性参数之一。常规的曳力系数测量主要采用重力沉降法,只适用于重颗粒、且表面光滑密实的情况,并不适用于像生物质这类非球形、轻质颗粒的曳力系数的测量。本文介绍一种非球形、轻质颗粒曳力系数的高速摄像测量方法,基于颗粒视频、图像的处理方法,分析在测量区域内颗粒的受力大小和迎风截面的变化.应用该方法测量两种典型球形、圆盘状颗粒的曳力系数,实验结果表明球形颗粒的测量结果与标准曳力曲线预测的结果变化趋势一致;对于圆盘状颗粒,其测量结果与非球形颗粒曳力系数的Hoizer经验公式计算值相比,存在20%的平均误差。
Drag coefficient is one of fundamental parameters for showing the strength of interaction between gas and particles.Traditionally,the gravity sedimentation method is applied to measure drag coefficient through observing particle terminal velocity in a liquid.In this case,the particle's density should be greater than the liquid's and its surface should be smooth and tight,rather than being porous like biomass particles.In this paper,a method based on high speed photography is introduced to measure drag coefficient of several typical particles with the regular geometric type such as sphere,cylinder and disc,etc.The experimental result for spherical particle is in good agreement with the standard curve of drag coefficient.And the results for non-spherical particles are with the20%percent difference compared with that published in the other public literatures.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2015年第2期351-355,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金项目(No.51376048)
关键词
曳力系数
非球形颗粒
高速摄影
图像处理
drag coefficient
non-spherical particles
high speed photography
image processing
