LES of Wind-Wave-Current Interaction in Coastal Area
Abstract
We propose to use large-eddy simulations (LES) to study coastal land-air-sea interaction (CLASI), as part of the CLASI DRI. The simulations will use our powerful computation package WOW (Wave-Ocean-Wind), which has a suite of modules capable of resolving realistic land surface topography while accurately simulating wave field, turbulent wind field, temperature, and humidity. LES will be used as a tool to assist collaborators in the DRI in the planning of field deployment of measurement devices and post-analysis of measurement data. Prior to each deployment planning meeting, we will run various simulations based on realistic flow field statistics from mesoscale simulation using COAMPS, historical data, and in situ topography. The goal of these pre-deployment studies is to provide collaborators with guidance on the deployment of measurement instruments. Additionally, we will assist in the post-experiment analysis of measurement data. We will perform highly resolved and accurate simulations of each deployment site in order to provide a three dimensional, time varying flow field to assist in connecting the various measurement instruments by filling in the gaps. By assisting in both the development of the measurement deployment plan and assisting in the post-experiment analysis, we expect to improve the efficiency and accuracy of these measurements. In addition to assisting collaborators with measurement deployment design and data analysis, we intend to perform mechanistic studies of the processes over four representative realistic terrains: (1) sandy beach, (2) tidal inlet, (3) coastal mountains, and (4) urban environments. Studying these four cases will result in a comprehensive understanding of the most common coastal environments. For each of these terrains we plan to study a variety of parameters such as wind speed and direction, land topography, evaporation rate, and turbulent heat flux to learn about each parameter~s effect on the turbulent flow field. We also intend to use LES as a tool to study electromagnetic (EM) propagation, specifically by studying the effect of abrupt surface topography change and sea-to-land transition on the distribution of humidity and temperature in the near-surface flow field, and thus the refractive index for the EM signal propagation. The insights gained from the analyses will finally culminate in our plan to improve the parameterization of COAMPS. We aim to understand the fundamental reasons why the commonly used Monin-Obukhov similarity theory (MOST) fails to accurately capture the turbulent flow field in coastal regions. By understanding the weaknesses of MOST, we will be able to propose new methods of modeling the coastal domains in larger, mesoscale simulations. These new methods can then be tested and directly compared to the results of LES and measurement data to validate their accuracy and fidelity.This summary is approved for public release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 11, 2020
- Source ID
- N000142012103
Entities
People
- Lian Shen
Organizations
- Office of Naval Research
- Regents of the University of Minnesota
- United States Navy