布朗运动对Cu-水纳米流体传热效率的影响

Influence of Brownian Motion on the Heat Transfer Efficiency of Cu-Water Nanofluid

对三角形腔内Cu-水纳米流体的稳态自然对流传热问题进行数值模拟,建立完全高精度紧致差分方法,研究纳米流体瑞利数、纳米流体体积分数和纳米颗粒布朗运动对纳米流体对流传热效率的影响。数值结果表明,对于所考虑的瑞利数,无论考虑Cu纳米颗粒的布朗运动与否,纳米流体的对流传热效率都随着纳米流体体积分数的增加而增加;同时,当考虑Cu纳米颗粒的布朗运动时,纳米流体的传热效率略高于不考虑布朗运动时纳米流体的传热效率。在此基础上,建立Cu-水纳米流体传热效率与瑞利数、纳米颗粒的体积分数之间的修正模型。

Numerical simulation of the steady-state natural convection heat transfer of Cu-water nanofluid in a triangular cavity was carried out, and a fully high-order compact difference method was established, and the Rayleigh number, nanofluid volume fraction and Brownian motion of nanoparticle were studied.Numerical results showed that for the considered Rayleigh number, Brownian motion of the Cu nanoparticles was regarded or not, the convective heat transfer efficiency of the nanofluid increased with the increasing of the volume fraction of the Cu-water nanofluid.At the same time, when Brownian motion of nanoparticles was considered, the heat transfer efficiency of nanofluid was slightly higher than that of the nanofluid without Brownian motion.On this basis, a modified model among the heat transfer efficiency of Cu-water nanofluids, the Rayleigh number and the volume fraction of nanoparticles were established.