摘要
采用Fluent软件对圆环封闭腔内的Ag-水纳米流体自然对流传热进行数值模拟,着重分析在不同瑞利数下Ag纳米颗粒的添加量和圆环内外壁半径比对圆环传热性能的影响.研究结果表明,随着瑞利数的增加,圆环间的换热强度不断加剧,换热由热传导逐渐向对流转变.添加纳米颗粒降低了换热性能,且随着颗粒浓度的增加换热效果不断恶化;同时,圆环半径比对换热有很大的影响,对一定的瑞利数而言随着半径比的减小,换热性能逐渐增强,且增大的趋势越来越显著.
Natural convection in horizontal annuli with Ag-water nanofluids was investigated by a numerical study.And particle volume fraction and the ratio of annuli were studied for the evaluation of heat transfer properties in the annulus.It was observed that heat transfer performance increased and heat transfer in natural convection changed from conduction to convection with an augmentation of Rayleigh number.The average Nusselt number was reduced with the increase of the nanoparcticles volume fraction.It became more significant at higher particle volume fraction.The average Nusselt number has decreased with the augmentation of the radius ratio,especially at low radius ratio.
出处
《中国计量学院学报》
2013年第1期19-24,共6页
Journal of China Jiliang University
基金
国家自然科学基金资助项目(No.51106144)
中国博士后科学基金资助项目(No.2012M511362)
关键词
纳米流体
数值模拟
圆环
自然对流
nanofluids
numerical study
annuli
natural convection.
