School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, People's Republic of China.
Proc Natl Acad Sci U S A. 2022 Aug 16;119(33):e2202037119. doi: 10.1073/pnas.2202037119. Epub 2022 Aug 8.
The bronze goose-and-fish lamp exhibited in the national museum of China is a 2,000-y-old artifact once used for indoor lighting by nobility in the Western Han dynasty (206 BCE TO 25 CE). The beauty of this national treasure arises from its elegant shape vividly showing a goose catching fish with beautiful colors painted over the whole body. Beyond the artistic and historical value, what enchants people most is the eco-design concept of this oil-burning lamp. It is widely believed that the smoke generated by burning animal oil can flow into the goose belly through its long neck, then be absorbed by prefilled water in the belly, hence mitigating indoor air pollution. Although different mechanistic hypotheses such as natural convection and even the siphon effect have been proposed to qualitatively rationalize the above-claimed pollution mitigation function, due to the absence of a true scientific analysis, the definitive mechanism remains a mystery. By rigorous modeling of the nonisothermal fluid flow coupled with convection-diffusion of pollutant within and out of the lamp, we discover that it is the unnoticeable gap between goose body and lamp tray (i.e., an intrinsic feature of the multicompartmental design) that can offer definitive ventilation in the lamp. The ventilation is facilitated by natural convection due to oil burning. Adequate ventilation plays a key role in enabling pollution mitigation, as it allows pollutant to reach the goose belly, travel over and be absorbed by the water.
中国国家博物馆展出的铜雁鱼灯是一件 2000 年前的西汉贵族室内照明用具。这件国宝的美在于其优雅的造型，生动地展示了一只正在捕鱼的鹅，全身绘有美丽的色彩。除了艺术和历史价值，最吸引人的是这种油灯的生态设计理念。人们普遍认为，燃烧动物油产生的烟雾可以通过鹅的长脖子流入鹅的腹部，然后被腹部预先填充的水吸收，从而减轻室内空气污染。尽管已经提出了自然对流等不同的机械假设，甚至虹吸效应，来定性地合理化上述减轻污染的功能，但由于缺乏真正的科学分析，确切的机制仍然是一个谜。通过对油灯内和油灯外的非等温流体流动以及污染物的对流扩散进行严格建模，我们发现正是鹅身和灯盘之间难以察觉的缝隙（即多腔室设计的固有特征）为油灯提供了通风。由于燃烧油，自然对流促进了通风。充足的通风对减轻污染起着关键作用，因为它可以使污染物到达鹅的腹部，在水中传播并被吸收。
