Uncertainty quantification of injected droplet size in mono-dispersed Eulerian simulations

Théa Lancien (1) , Nicolas Dumont (1) , Kevin Prieur (1) , Daniel Durox (1) , Sébastien M. Candel (1) , Olivier Gicquel (1) , Ronan Vicquelin (1)

1 EM2C - Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion

Large-eddy simulations (LES) of a laboratory-scale two-phase burner are considered by describing the disperse liquid spray with a mono-disperse Eulerian approach. In this simplified framework, the choice of the size of the injected droplets becomes a critical issue. The impact of this key parameter upon the numerical results is carefully assessed though uncertainty quantification tools. Using Polynomial Chaos Expansion and Clenshaw-Curtis nested quadrature rule, several LES are performed for different injected droplet sizes in order to obtain a response surface of velocity and diameter fields at any point in the computational domain as a function of the injected one. Post-treatment of the response surface gives access to the precise impact of the chosen injected droplet size on the results. It is shown that information obtained from different mono-disperse simulations enables to answer a couple of practical questions in such two-phase flow simulations: How can the mono-disperse simulations be compared to the poly-disperse experimental results and their accuracy evaluated? More importantly, if only one simulation is to be carried out for a larger case, which value of the injected droplet size is the best?

Mots clés: Two-phase flows; Polynomial Chaos Expansion; Large Eddy Simulation; Eulerian-Eulerian approach

Domaines: Milieux fluides et réactifs

Théa Lancien, Nicolas Dumont, Kevin Prieur, Daniel Durox, Sébastien M. Candel, et al.. Uncertainty quantification of injected droplet size in mono-dispersed Eulerian simulations. 9th International Conference on Multiphase Flow, May 2016, Firenze, Italy. ⟨hal-01780997⟩