## Abstract

Large eddy simulation of turbulent reacting flows requires closure of the filtered chemical source term, which can be achieved using a presumed form of the joint subfilter probability density function (PDF) of the controlling scalars. In the flamelet/progress variable approach, the controlling scalars are the mixture fraction and progress variable, and a beta distribution is most often used to model the marginal subfilter PDF of the mixture fraction. Recent advances on this class of model allow for multiple inlets by defining additional mixture fractions and therefore require a model for the joint subfilter PDF of these mixture fractions. Several models have been proposed, including the statistically-most-likely distribution, the Dirichlet distribution, and a more general bivariate form of the b-distribution. In this work, direct numerical simulations of multiscalar mixing in isotropic homogeneous turbulence are used to provide a physical basis for selecting an appropriate subfilter PDF model. This is further supported mathematically by applying the concept of statistical neutrality for the proposed distributions.

Original language | English (US) |
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State | Published - 2017 |

Externally published | Yes |

Event | 10th U.S. National Combustion Meeting - College Park, United States Duration: Apr 23 2017 → Apr 26 2017 |

### Other

Other | 10th U.S. National Combustion Meeting |
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Country/Territory | United States |

City | College Park |

Period | 4/23/17 → 4/26/17 |

## All Science Journal Classification (ASJC) codes

- General Chemical Engineering
- Physical and Theoretical Chemistry
- Mechanical Engineering

## Keywords

- Large eddy simulation
- Subfilter PDF
- Turbulent mixing