Coherent Structures and Mixing in Rotating and Stratified Flows

New Mexico Consortium, Los Alamos NM

Investigators

Abstract

This is a proposal to explore and model the structure of turbulence that leads to mixing in turbulent flows. The work will focus on cases of anisotropic turbulence, an area that has not been explored as much as other turbulent flows, but is of the utmost importance in engineering and in the environment. The research proposed in this work covers computations at a multitude of scales, even scales relevant to geophysical flows, allowing the results to be useful not only because of the fundamental aspect of turbulent mixing, but also due to applicability in practical situations. Our climate, agriculture, and commerce are affected by turbulence in the atmosphere and in the ocean. This work could lead to more accurate models for ocean and atmospheric flows with impact on policy, economic and infrastructure decision. The data that will be generated will become available to the scientific community through the established Johns Hopkins University Turbulence Database. In addition, graduate students will participate in this project. The goal of the proposed study is to investigate rotation and stratification effects and the scales at which different mixing dynamics are active in a turbulent flow. The PI proposes to use state-of-the-art direct numerical simulations (DNS) code and to run several large calculations using computational resources that are quite impressive (available through allocations from the DOE Office of Science). The proposed work aims to advance our fundamental understanding of turbulent mixing by, 1) characterizing and quantifying the instrinsic scales of coherent structures formed in canonical rotating and stratified flows using statistical measures and, 2) quantifying the relationship of the scales thus recovered to the statistics and the instrinsic scales of mixing.