有序涡旋对三角槽道脉动流强化传热的影响

发布时间：2017-12-28 11:27

本文关键词：有序涡旋对三角槽道脉动流强化传热的影响　出处：《化工学报》2016年09期 　论文类型：期刊论文

【摘要】：以水为工质对三角槽道内单相液体充分发展层流脉动传热特性进行了研究。应用粒子图像测速技术(PIV)测得流场内涡的变化规律,从"涡及涡运动"的角度揭示了"有序"的涡生长及迁移过程对脉动流强化传热的影响。此外,应用"场协同"理论,通过数值模拟深入分析了流场特性与传热之间的关系。研究发现,"有序"的涡生长及迁移过程,破坏了流体边界层,促进了近壁区热流场与速度场的协同,同时,强化了三角槽道内流体与主流区流体的掺混,热量输运能力提升;存在最佳的Strouhal数(St),使得涡旋既能充分发展又能在较短时间脱落进入主流,实现最大效率的壁面换热;有序涡旋对速度场、温度梯度场以及压力梯度场三者协同性的改善是换热性能提升的关键。
[Abstract]:The characteristics of laminar flow pulsating heat transfer in a single phase liquid in a triangular channel are studied with water as a working fluid. Particle image velocimetry (PIV) is applied to measure the variation of vorticity in the flow field. From the perspective of "vortex and vortex motion", the influence of "ordered" vortex growth and migration process on heat transfer enhancement in pulsating flow is revealed. In addition, the relationship between the flow field characteristics and the heat transfer is analyzed by numerical simulation by using the field synergy theory. The study found that the vortex growth and migration process in order ", damage the flow boundary layer, promote synergy, flow field and velocity field in the near wall region at the same time, strengthen the river channel flow and mainstream flow mixing, heat transport capability; there exists an optimal number of Strouhal (St). The vortex can be fully developed and in a relatively short time falling into the mainstream, to achieve the maximum efficiency of the wall heat transfer; ordered vortex on the velocity field, temperature field and pressure gradient field three synergistic improvement is the key to improving the performance of heat exchanger.
【作者单位】：浙江工业大学能源与动力工程研究所脉动技术工程研究中心;
【基金】：浙江省科技厅资助项目(2014C31034)~~
【分类号】：TK124
【正文快照】： 引言热量的传递过程广泛存在于动力、核能、制冷、化工、石油、航空等行业中。换热器在上述各行业中不仅是保证工程设备正常运转不可或缺的部件,而且在金属消耗、动力消耗和投资方面占有重要份额。例如在制冷机中,换热器的动力消耗占总能耗的20%~30%[1];化工企业里,换热器的能

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