EAGER: The Dynamics of Large Buoyant Plumes

该奖项是为了研究由非常大的火灾引发的垂直羽流。 经典的例子是核武器爆炸，这将导致大规模的火灾，将烟尘和灰烬送到大气层中。 正如火山记录的那样，如果这些物质在大气中达到一定水平，它们可以长时间悬浮并冷却地球表面。 该项目将利用现代计算工具重新审视大火产生的羽流概念。 这项研究可能会产生政策影响，并将有助于教育和培训下一代科学家。EAGER奖的总体目标是为非常大的火灾（如核武器爆炸引发的火灾）上方的流动发展一个通用理论。 该项目的首席科学家提出，鉴于火灾的基本特征，我们无法预测由此产生的羽流的浮力。如果没有浮力估计，我们就无法预测烟羽的中性浮力水平或气溶胶最终在大气中停留的高度。 研究小组将制定一个理论，提供估计的初始高度，水平宽度和特征浮力的流体出现的自旋层。有了这个理论，研究人员将初始化垂直羽流，并研究在垂直羽流中向上发射的空气的命运。 其目的是制定一个理论的羽的水平的中性浮力。 该方法将是爬上的层次从二维干未分层的初步结果，一个全面的理论，现实的羽流在三维潮湿的分层大气。 该理论的结果将通过大涡和直接数值模拟（LES和DNS）的高分辨率模拟进行验证。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is for the study of vertical plumes that are initiated from very large fires. The classic example is detonations of nuclear weapons which would result in massive fires, sending soot and ash far up into the atmosphere. As has been documented with volcanoes, if the materials reach a certain level in the atmosphere they can stay suspended for a long time and cool the surface of the Earth. This project will revisit the concept of plumes originating from large fires using modern computational tools. The research may have policy implications and will contribute to the education and training of the next generation of scientists.The overarching goal of this EAGER award is to develop a general theory for the flow above very large fires, such as those initiated by the detonation of a nuclear weapon. The lead scientist for this project makes the case that given the basic characteristics of a fire, we are unable to predict the buoyancy of the resultant plume. And without a buoyancy estimate, we cannot predict the plume's level of neutral buoyancy or the height at which aerosols will ultimately reside in the atmosphere. The research team will formulate a theory that provides estimates of the initial height, horizontal width, and characteristic buoyancy of the fluid emerging from the spin-up layer. With this theory in hand, the researchers will initialize the vertical plume and study the fate of the air launched upwards in the vertical plume. The aim is to formulate a theory for the plume's level of neutral buoyancy. The approach will be to climb up the hierarchy from 2D dry unstratified initial results to a comprehensive theory for realistic plumes in a 3D moist stratified atmosphere. The results of this theory will be validated against high-resolution simulations from Large Eddy and Direct Numerical Simulations (LES and DNS).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.