污泥受动态剪切时的壁面滑移试验研究  

Experimental study of sewage sludge on the dynamic shear wall slip

作　　者：张晓斌[1,2] 冯民权[1] 孙西欢[2] 李国栋[1] 马修元[3] 

机构地区：[1]西安理工大学教育部与陕西省共建西北水资源与生态环境重点实验室,西安710048 [2]山西水利职业技术学院,山西运城044000 [3]东南大学能源与环境学院,南京210096

出　　处：《水动力学研究与进展（A辑）》2013年第6期658-664,共7页Chinese Journal of Hydrodynamics

基　　金：国家重点基础研究发展计划(973计划;2010CB227001);陕西省教育厅重点实验室科学研究计划项目(2010JS030)~~

摘　　要：为了研究城市脱水污泥发生壁面滑移时可能受到的影响因素,该文在常温下用平行板旋转流变仪(AR2000)并借助高速摄像机对污泥(含水率为81.3%)壁面滑移现象进行了试验分析。结果发现,污泥受到动态剪切时,在一定时间内发生了滑移现象,且剪切速率扫描曲线随着速率的增大,表现出一定的黏弹性。同时在角频率为低频0.5 rad/s、中频6.28 rad/s和高频12.56 rad/s三种情况下对应变进行扫描,按照Cho等[13]提出的应力进行分解,对总剪切应力、弹性应力和黏性应力等各种影响壁面滑移的有关力的因素进行分析,发现存在一个无量纲参数*??/G,即弹性应力与线性区复数模量的比值在0.21―0.27之间,并且该参数随着角频率的增大而缓慢下降。由此表明时间对污泥壁面滑移有一定的影响,其中弹性应力起了主要作用。In order to study the influencing factors of the city dewatered sludge when wall slip happens, this paper takes experimental analysis on sludge （water content 81.3%） wall slip phenomena using the parallel plate rotational rheometer （AR2000） at room temperature and by means of high speed camera. The results are found, when sludge is dynamically sheared,slid phenomenon happens in a viscoelastic. At the same time, certain period of time. And the shear rate sweep curve with the rate increasing shows some scanning strain in three cases that the comer frequencies are low frequency 0.5 rad/s, medium frequency 6.28 rad/s and high frequency 12.56 rad/s, the various effects of wall slip on force including the total shear stress, elastic stress, viscous stress are analyzed, it is decomposed according to the stress proposed by Cho et al.. It is found that there is a dimensionless parameter τ＇/｜G＊｜, the ratio of elastic stress and the complex modulus in linear region between 0.21-0.27, and this parameter decreases slowly with increasing the comer frequency, which showed that time has some effect on sludge wall slip and the elastic stress plays the main role.

关 键 词：城市污泥 壁面滑移 动态剪切 应力分解 

分 类 号：O373[理学—流体力学]