Experimental investigation of biomimetic self-pumping and self-adaptive transpiration cooling
Experimental investigation of biomimetic self-pumping and self-adaptive transpiration cooling
复制标题
DOI：
10.1088/1748-3190/aa753b
复制
发表时间：
2017-09
影响因子：
3.4
通讯作者：
P. Jiang;Gan Huang;Yinhai Zhu;R. Xu;Zhiyuan Liao;Taojie Lu
中科院分区：
文献类型：
--
作者：
P. Jiang;Gan Huang;Yinhai Zhu;R. Xu;Zhiyuan Liao;Taojie Lu
蒸腾冷却是保护高热流密度墙体的有效方法。然而，用于蒸腾冷却系统的泵使系统更加复杂，并且增加了负载，这对实际应用来说是一个巨大的挑战。受树木蒸腾过程的启发，研制了一种无需泵的仿生自抽蒸腾冷却系统。实验研究表明，在不需要泵的情况下，水冷剂自动从水箱流向热表面，高度差为80mm。在此基础上研制了自适应蒸腾冷却系统。当加热火焰温度为1639 K，热流密度约为0.42 MW m−2时，系统有效地冷却了热表面，表面温度保持在373 K左右。冷却效率达94.5%。随着火焰热流从0.24 MW m−2增加到0.42 MW m−2，冷却剂质量流量自适应增加，冷却表面温度保持在373 K左右。纹影照片显示，热表面上有一层保护蒸汽层，它阻挡了火焰的热流到热表面。保护蒸汽层厚度随热流密度的增大而增大。
Transpiration cooling is an effective way to protect high heat flux walls. However, the pumps for the transpiration cooling system make the system more complex and increase the load, which is a huge challenge for practical applications. A biomimetic self-pumping transpiration cooling system was developed inspired by the process of trees transpiration that has no pumps. An experimental investigation showed that the water coolant automatically flowed from the water tank to the hot surface with a height difference of 80 mm without any pumps. A self-adaptive transpiration cooling system was then developed based on this mechanism. The system effectively cooled the hot surface with the surface temperature kept to about 373 K when the heating flame temperature was 1639 K and the heat flux was about 0.42 MW m−2. The cooling efficiency reached 94.5%. The coolant mass flow rate adaptively increased with increasing flame heat flux from 0.24 MW m−2 to 0.42 MW m−2 while the cooled surface temperature stayed around 373 K. Schlieren pictures showed a protective steam layer on the hot surface which blocked the flame heat flux to the hot surface. The protective steam layer thickness also increased with increasing heat flux.