(322c) Conditional Moment Methods for Turbulent Reacting Flows

In turbulent reacting flows, due to presence of turbulence-chemistry interactions, the source terms in the Reynolds-averaged transport equations are unclosed. A common method for closure in computational fluid dynamics (CFD) applications is a moment-based method. Among them, the conditional moment closure (CMC) is a promising candidate, which solves the conditionally averaged transport equations of the joint probability density function of reactive scalars, while the chemical source terms are written in terms of the conditional scalar means [1]. In our recent study, [2] the idea of the application of Gaussian quadrature-based moment methods (QBMM) to the first-order CMC is exploited by first deriving a closed set of differential transport equations of the higher-order moments of joint mixture-fraction and reaction-progress variable, which are then solved via the conditional quadrature method of moments [3]. To show the effect of degree of correlation to the product yield as well as the application of QBMM-CMC, three-dimensional CFD simulations are run inside a multi-inlet vortex reactor with two-step parallel acid-base liquid phase reaction.

References:

1. R. O. Fox, “Computational Models for Turbulent Reacting Flows”, Cambridge University Press, Cambridge, UK (2003).

2. A. D. Ilgun, A. Passalacqua, and R. O. Fox, “Solution of the first-order conditional moment closure for multiphase reacting flows using quadrature-based moment methods,” Chem. Eng. J. 405, 127020 (2021).

3. C. Yuan and R. O. Fox, “Conditional quadrature method of moments for kinetic equations,” J. Comput. Phys. 230(22), 8216–8246 (2011).