纳米流体在芯片微通道中的流动与换热特性

对去离子水及体积分数分别为0.15%和0.26%的水基γ-Al₂O₃纳米流体在当量直径为194.5 μm的硅基梯形芯片微通道内的层流流动和换热特性进行了实验研究。考察了Reynolds数、Prandtl数以及体积分数对流动换热的影响。结果发现，使用纳米流体后，压降无明显增加，纳米流体的流动阻力特性与去离子水基本相同;对流换热Nusselt数较去离子水有明显提高，且随着体积分数的增加而增加;相同泵功下换热热阻显著下降。实验还发现纳米流体的强化传热效果在较高温度时更加明显。根据实验数据得到了梯形硅微通道内低浓度纳米流体的层流对流换热关联式。研究结果对于集成高效芯片散热系统设计具有重要意义。

Flow and heat transfer characteristics of nanofluids in silicon chip microchannels

An experimental investigation was performed on the single-phase flow and heat transfer characteristics through silicon-based trapezoidal microchannels with a hydraulic diameter of 194.5 μm using deionized (DI) water and γ-Al₂O₃ nanofluids of volume fractions 0.15 % and 0.26% respectively.The effects of Reynolds number, Prandtl number and nanoparticle concentration on the convective heat transfer characteristics were investigated.The results showed that the pressure drop and flow resistance for nanofluids and DI water were approximately the same, but the Nusselt number of nanofluids increased considerably as compared with that of DI water.With the same pumping power, using nanofluids instead of DI water caused the reduction in thermal resistance.It was also found that Nusselt number increased with the increase in nanoparticle concentration, and the heat transfer enhancement was more obvious at the higher bulk temperature of nanofluids.Based on the experimental data, a dimensionless correlation of Nusselt number was proposed.The results presented in this paper help to guide the design of high efficiency integrated chip cooling system.