航天用纳米流体流动与传热特性的实验研究

研究航天用纳米流体流动与传热特性。测量了不同粒子体积份额的航天用纳米流体雷诺数500~4000范围内的管内对流换热系数和摩擦阻力系数,详细讨论了雷诺数和纳米粒子体积份额对纳米流体对流换热系数和摩擦阻力系数的影响,分析了航天用纳米流体的强化传热性能。实验结果表明,在液体中添加纳米粒子增大了液体的管内对流换热系数,增加了液体的传热效果,粒子的体积份额是影响纳米流体对流换热系数的因素之一,在相同雷诺数条件下,纳米流体的对流换热系数随粒子体积份额的增加而增大。与原液体工质相比,航天用纳米流体的流动阻力系数稍有增大,纳米流体的流动阻力系数不随纳米粒子的体积份额而变化。与航天用纳米流体对流换热系数的增加相比,纳米流体流动阻力系数增大的程度极小,验证了纳米流体强化传热技术应用于航天器热控系统的可行性。

Experimental Investigation on Flow and Convective Heat Transfer Feature of A Nanofluid for Aerospace Thermal Management

This paper studied the feature of flowing and heat transfer of spacecrafts nanofluid. both the convective heat transfer coefficient and friction factor of a new nanofluid for thermal management of spacecrafts flowing in a tube were measured, respectively. The effects of many factors as the volume fraction of suspended nanoparticles and the Reynolds number on the heat transfer and flow characteristics were discussed in detail. The experimental results showed that the suspended nanoparticles remarkably increased the convective heat transfer coefficient in comparison with that of the base fluid and showed that the heat transfer feature of a nanofluid increased with the volume fraction of nanoparticles. The friction factor of the nanofluid was higher than that for the pure fluid under the same Reynolds number. Comparison between the enhancement of convective heat transfer and the increment of pressure drop of the nanofluid for aerospace application showed that the increment of the friction factor of the nanofluid was much lower than the enhancement magnitude of the convective heat transfer coefficient of the nanofluid. It is expected that this type of the nanofluid is suitable for practical application in thermal management system of spacecrafts.