摘要
宏观不稳定性是搅拌槽内流体运动能量耗散与流场大涡运移的综合表现。控制流体的宏观不稳定性有助于提高流体的混合效率,降低操作能耗。实验以LabView软件采集搅拌槽反应器某点压力脉动信号,数据经过小波分析处理后得到流体的宏观不稳定频率。实验对比研究了液相/气-液两相流体宏观不稳定频率变化趋势。结果表明,液体混合的宏观不稳定频率与搅拌桨转速呈线性关系,而气-液混合反应器内流体的宏观不稳定特征频率消失,出现谱带现象。流场拟序结构尺度变化导致混沌混合特性得到增强。
Marco-instability(MI)is the flow character of energy dissipation and movement of large eddies in the stirred tank.To adjust MI can improve mixing performance and reduce energy consumption.Pressure variation signal data were collected with the software LabView,and MI frequency was obtained by wavelet analysis.MI difference between liquid and gas-liquid mixing was comparatively investigated.Results showed that in liquid mixing system,MI frequency was propotional to agitation speed,while in gas-liquid mixing system,the characteristic MI frequency was replaced with spectrum band.Chaotic mixing performance was enhanced by air jet-impeller agitation process because of multiscale structure in flow field.
出处
《化工进展》
EI
CAS
CSCD
北大核心
2010年第S2期100-105,共6页
Chemical Industry and Engineering Progress
基金
国家自然科学基金(20806095)
国家高技术发展研究计划(863)重点项目(2008AA031202)
留学回国人员科研启动基金项目(教外司留20091341-2)
国家火炬计划项目(2010GH051695)
中央直属高校基本科研业务费项目(CDJZR10220001)资助
关键词
搅拌槽
宏观不稳定性
压力脉动
拟序结构
stirred tank
macro-instability
pressure fluctuation
coherent structure
