A Mixing Study Using Coherent Structure Dynamics to Drive a Surrogate Fluid Dynamics Model
Abstract
This paper uses a reduced-order Coherent Structure Dynamics model, introduced in an earlier paper, to compute the time-dependent interspecies mixing due to a non-equilibrium spectrum of fluid dynamic turbulence expressing interactions between the coherent structures observed in turbulence (Brown and Roshko, 1974). The Coherent Structure Dynamics (CSD) model addresses situations where the time-scale for changes in the fluid dynamics driving the turbulence is short. The turbulence will be far from equilibrium when the turbulent small scales do not have time to reach their equilibrium strength. True molecular mixing and thus chemical reactions of initially separate species depends on the short scales in the velocity spectrum to mix the species. Surrogate Fluid Dynamic (SFD) realizations of such a turbulent flow, driven by the time-dependent CSD turbulence spectrum, are computed in a triply-periodic cube of a tracer density to study the mixing of two chemical species. This paper measures the time delay in molecular-scale mixing caused by the non-equilibrium delay to establish the small turbulent scales that bring the species close enough to mix molecularly.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 29, 2021
- Accession Number
- AD1144458
Entities
People
- Jay Paul Boris
Organizations
- United States Naval Research Laboratory