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Large Eddy Simulation of Turbulence at the Sediment-Water Interface


EMSL Project ID
50508

Abstract

Understanding the fundamental connections between surface and groundwater is a critical component of the current PNNL Subsurface Science Scientific Focus Area (SFA). The sediment-water interface in the Columbia River is an important boundary where surface and groundwater components can mix and be exchanged. Thus, developing an accurate mechanistic understanding of the mass and momentum exchange processes in this region are important for developing accurate, science-based hydrologic models such as PFLOTRAN (the large-scale hydrologic model currently adopted by PNNL). The main objectives of the proposed work are to perform a limited suite of particle-resolved LES for (i) turbulent flow and (ii) solute transport over a flat, porous bed for a range of free-stream Reynolds numbers turbulence of $10^4$--$10^5$, which is representative of small streams, in the minimal flow unit necessary to maintain turbulence. The pressure and velocity fluctuations over the porous bed will be quantified using energy spectra, auto-correlations, and turbulence kinetic energy budget. The data will be compared against non-porous, smooth beds to obtain insights into the effect of porous bed on turbulence and solute transport. To conduct these simulations, computing time of 200,000 node-hours on Cascade is requested.

Project Details

Project type
Exploratory Research
Start Date
2018-10-21
End Date
2019-09-30
Status
Closed

Team

Principal Investigator

Sourabh Apte
Institution
Oregon State University

Team Members

Xiaoliang He
Institution
Pacific Northwest National Laboratory