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基于计算流体动力学?离散相模型模拟研究恒热流密度条件下3D圆形管道内相变微胶囊悬浮液(Micro-PCMS)紊流的对流传热特性,讨论了微胶囊质量分数对管道内悬浮液速度、温度及壁面温度的影响,获得了沿流动方向不同截面的速度分布、温度分布及修正的局部Nu数.结果表明,靠近管道壁面处,相变微胶囊的存在使悬浮液速度降低,且随其含量增加而降低愈加明显;管内悬浮液温度分布分为非融化区、融化区和完全融化区;管道壁面温度、悬浮液出口温度均比纯水降低,相变微胶囊含量为12%,16%,20%(?)时,出口处悬浮液温度分别降低25.5%,33.9%,42.4%,壁面温度分别降低23.9%,31.0%,39.2%.且因存在相变吸热及扰动的共同效应,管道内温度分布从规则的抛物线形逐渐演变为具有尖峰的曲线.
The convection heat transfer characteristics of the phase-change microcapsule suspension (Micro-PCMS) turbulent flow in a 3D circular tube under constant heat flux density were studied based on the computational fluid dynamics (DFT) discrete phase model. The effects of microcapsule mass fraction Liquid velocity, temperature and wall temperature, the velocity distribution, temperature distribution and the modified local Nu numbers of different sections along the flow direction were obtained.The results show that the phase velocity microcapsules near the pipe wall reduce the velocity of suspension, The temperature distribution in the pipe was divided into non-melting zone, melting zone and completely melting zone. The temperature of the pipe wall and the outlet temperature of the suspension were all lower than that of the pure water. The content of the phase-change microcapsule was 12% , 16% and 20% (?), The temperature of the outlet suspension decreased by 25.5%, 33.9% and 42.4% respectively, and the wall temperature decreased by 23.9%, 31.0% and 39.2% The common effect is that the temperature distribution in the pipeline gradually evolves from the regular parabola to the curve with spikes.