Quantifying structural uncertainty in the BHR model for variable-density flows

TL;DR

This paper develops a framework to quantify and reduce structural uncertainties in the BHR model for variable-density flows by extending eigenspace perturbation methods to various canonical flow cases.

Contribution

It introduces a novel uncertainty quantification strategy for the BHR model using eigenspace perturbation tailored for variable-density flows.

Findings

Effective uncertainty quantification in 1D Rayleigh-Taylor instability

Application to turbulent jet mixing flows

Extension of eigenspace perturbation to variable-density models

Abstract

In this brief, we try to develop a comprehensive framework to identify, quantify, isolate, and reduce the uncertainties in the original BHR model \citep {Besnard1992} for variable-density flows. Because the eigenspace perturbation of Reynolds stress successfully accounts for the structural uncertainty in many flows, we first extend this methodology to the BHR model for variable-density flows with different $At$. The philosophy of eigenspace perturbation in Reynolds stress, i.e., quantifying the states of maximizing and minimizing the production mechanism, has led to the proposals of the structural uncertainty quantification strategy in the BHR model for variable-density flows. Several canonical flows, including one-dimensional (1D) Rayleigh-Taylor instability (1DRT), Rayleigh-Taylor mixing in a tilted rig (TR) and turbulent jet mixing flow, are investigated.