凹槽形腔体内TiO2-水纳米流体自然对流数值研究

摘要

采用数值模拟方法对凹槽形腔体内TiO 2-水纳米流体的自然对流换热进行了研究,重点讨论了Ra数、纳米颗粒体积分数φ 和热源尺寸的变化对自然对流换热的影响.结果表明:添加纳米颗粒能够明显提高自然对流换热强度,在给定的Ra数下,随着纳米颗粒体积分数φ 的增加,纳米流体的自然对流换热强度明显提高;在给定的纳米颗粒体积分数φ 下,随着Ra数的增加,纳米流体的换热强度也同时增强;当Ra=105时,随着热源尺寸的增加,热壁面的平均Nu数也增加.%Natural-convection heat transfer of TiO 2 -H 2 O nanofluids in groove cavity is studied by numeri-cal simulation method,the emphasis is the effect of Ra ,nano-particles volume fraction φ and heat source dimensional change on natural-convection heat transfer.The result shows that adding nano particles can magnificently improve natural convection heat transfer intensity;under constant Ra ,natural convection heat transfer intensity of nanofluids magnificently increase with nano particle fraction φ increasing;under constant nano particle volume fractionφ,heat transfer intensity of nanofluids increase simultaneously with Ra increasing;when Ra =105 ,the mean Nu of hot wall increases with heat source dimension increasing.