Campus Units

Chemical and Biological Engineering, Mechanical Engineering

Document Type


Research Focus Area

Computational Fluid Dynamics

Publication Version

Accepted Manuscript

Publication Date


Journal or Book Title

Chemical Engineering Journal



First Page





The quadrature-based semi-analytical solution for the conditional moment closure (SA-CMC) given in (A. D. Ilgun, A. Passalacqua, and R. O. Fox, “A quadrature-based conditional moment closure for mixing-sensitive reactions,” Chem. Eng. Sci., 226, 2020) eliminates the additional conditioning-space discretization in CMC applications by assuming that the mixture-fraction PDF is well represented by a β-PDF. A Gaussian quadrature provides the mixture-fraction abscissae, and the conditional scalar mean is expressed in terms of Jacobi polynomials. Here, by preserving the computational efficiency of SA-CMC, a novel quadrature-based moment method (QBMM-CMC) is developed for CMC applications, which does not assume the form of the mixture-fraction PDF. Remarkably, by solving the closed forms for the micromixing terms from CMC, exact expressions result for the mixture-fraction moments of any order. Thus, QBMM-CMC covers cases where the mixture-fraction PDF cannot be well represented by a β-PDF and can be applied to disperse multiphase flows with mass transfer (e.g., droplet evaporation). For single-phase and multiphase pure-mixing problems, the QBMM-CMC mixture-fraction moments are observed to deviate from the β-PDF. For single-phase mixing with and without dispersed-phase mass transfer, QBMM-CMC predictions for mixing-sensitive competitive-consecutive and parallel reactions are investigated parametrically.


This is a manuscript of an article published as Ilgun, A. D., R. O. Fox, and A. Passalacqua. "Solution of the first-order conditional moment closure for multiphase reacting flows using quadrature-based moment methods." Chemical Engineering Journal (2020): 127020. DOI: 10.1016/j.cej.2020.127020. Posted with permission.

Copyright Owner

Elsevier B.V.



File Format


Available for download on Thursday, September 15, 2022

Published Version