Cloud Droplet Collisions in Turbulent Environment: Collision Statistics and Parameterization
Cloud Droplet Collisions in Turbulent Environment: Collision Statistics and Parameterization
复制标题
湍流环境中的云滴碰撞：碰撞统计和参数化
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Kevin Zwijsen
中科院分区：
文献类型：
--
作者：
Sisi Chen;P. Bartello;M. Yau;P. Vaillancourt;Kevin Zwijsen
AbstractThe本文的目的是通过分别研究计算域大小，涡耗散率（EDRs）和液滴大小的影响，并最终开发一个准确的碰撞内核参数化的碰撞统计中的湍流的影响进行量化。直接数值模拟（DNS）进行了一个相对较宽的EDR和泰勒微尺度雷诺数的范围。EDR测量湍流强度水平。DNS模式研究模拟了云的绝热核心中的一个小区域内的均匀湍流。云显然比当前DNS可以模拟的规模大得多。因此，需要强调的是，从目前的DNS中获得的基本上只是一个给定EDR的计算域大小的度量，不能完全描述云湍流的物理特性。结果表明，只要液滴尺寸小于25 μm，碰撞统计与畴的大小无关，因此与计算结果无关。
AbstractThe purpose of this paper is to quantify the influence of turbulence in collision statistics by separately studying the impacts of computational domain sizes, eddy dissipation rates (EDRs), and droplet sizes and eventually to develop an accurate parameterization of collision kernels. Direct numerical simulations (DNS) were performed with a relatively wide range of EDRs and Taylor microscale Reynolds numbers . EDR measures the turbulence intensity levels. DNS model studies have simulated homogeneous turbulence in a small domain in the cloud’s adiabatic core. Clouds clearly have much larger scales than current DNS can simulate. For this reason, it is emphasized that obtained from current DNS is fundamentally only a measure of the computational domain size for a given EDR and cannot completely describe the physical properties of cloud turbulence. Results show that the collision statistics are independent of the domain sizes and hence of the computational for droplet sizes no bigger than 25 μm as long...