CAREER: Scalar Transport in High Reynolds Number Boundary Layer with Heterogeneous Roughness and Source Flux: Modeling Marine Aerosol in Coastal Regions

这项研究的目标是更好地了解粗糙表面上湍流的传输，因为这一理解对于广泛的科学和工程应用非常重要，例如污染物传输、城市流动、花粉传播、空气质量、通信用电磁波的传播。该项目将侧重于沿海地区的海洋气溶胶输送，包括海岸粗糙度和海浪产生的气溶胶。湍流扩散输运在自然界中是常见的，但目前的理解是基于简单的流动情况，而不是实际应用。该项目将通过一种基于物理的方法来推动未来几代湍流扩散过程的模型。综合教育计划涉及STEM、边界层流动、湍流，并将产生广泛的影响，具体做法是：1)教育学生了解大气湍流对环境流动的作用；2)让高中生和本科生团队参与与研究有关的设计项目；3)通过激光雷达夏令营和为弱势青年服务的社区图书馆轮流展览，提高对边界层流动对环境作用的认识。这项工作将涉及传统上代表性不足的学生，并反映达拉斯-沃斯堡大都会地区的不同人口统计学特征。该项目将包括三项相互关联的任务：i)在得克萨斯州加尔维斯顿湾海岸的激光雷达实地活动，在海洋大气边界层进行同时和共同位置的风和海洋气溶胶测量；ii)应用机器学习模型来描述、分类和预测海洋-气溶胶输送的各种湍流过程；iii)发展在表层没有平衡条件下标量输送的全张量涡旋扩散率模式。拟议项目的目标是：1)表征和模拟高度和流向上的标量浓度，作为地面粗糙度可变性和局部源通量的函数；2)研究在没有平衡条件的情况下，大型含能湍流结构在表面层内气溶胶浓度重新组织中的作用；3)建立标量输送的涡扩散模型，作为非均匀地面气溶胶通量和粗糙度的统计函数。该奖项反映了NSF的法定任务，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The goals of this research is to better understand transport by turbulent flow over rough surfaces since this understanding is important for a broad range of scientific and engineering applications, such as pollutant transport, urban flows, pollen dispersion, air quality, propagation of electromagnetic waves for communication. This project will focus on the transport of marine aerosol in coastal regions, accounting for shore roughness and aerosol generation from waves. Transport by turbulent diffusion is common in nature, yet current understanding is based on simplistic flow cases rather than real applications. This project will drive future generations of models for turbulent diffusion processes through a physics-based approach. The integrated education plan is at the interface of STEM, boundary-layer flows, turbulence, and will have a broad impact by: 1) educating students about the role of atmospheric turbulence for environmental flows; 2) involving teams of high school and undergraduate students in research-related design projects; 3) promoting awareness about the role of boundary-layer flows for the environment through the LiDAR summer camp and exhibits for rotation in community libraries serving disadvantaged youth. This work will involve traditionally under-represented students and reflect the diverse demographics of the Dallas-Fort Worth metroplex area.This project will encompass three interrelated tasks: i) A LiDAR field campaign at the coast of Galveston Bay in Texas to perform simultaneous and co-located wind and marine aerosol measurements in the marine atmospheric boundary layer; ii) Application of machine learning models to characterize, classify and predict various turbulent processes for marine-aerosol transport; iii) Development of fully tensorial eddy-diffusivity models for scalar transport in absence of equilibrium condition in the surface layer. The goals of the proposed project are: 1) Characterize and model scalar concentration over height and streamwise direction as a function of surface roughness variability and local source flux; 2) Investigate the role of large energy-containing turbulent structures in the re-organization of aerosol concentration within the surface layer in absence of equilibrium condition; 3) Develop eddy-diffusivity models for scalar transport as a function of statistics of heterogeneous surface aerosol flux and roughness.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.