Co-utilization of experiments and large eddy simulations in turbulent combustion

Interactions between experiments and LES typically have taken similar forms to interactions between experiments and RANS. That is, experimental data may offer physical justification for a closure model, help specify boundary conditions for a simulation, and provide metrics – generally in the form of low-order moments – to compare against the simulation results. While this approach has led to steady improvements in LES fidelity, truly predictive simulations of complicated phenomena in realistic combustors remain an aspirational goal. On the experimental side, design of experiments and conversion of acquired signals to physical quantities of interest has progressed with limited input from simulations.

This presentation will discuss richer methods of experiment/LES interaction. We first will consider the use of 3D (and 4D) experimental data to directly assess closure models. This has the potential to overcome some of the computational cost restrictions regarding a priori analysis of DNS, and to determine how well closure paradigms hold in realistic configurations. We then will discuss the assimilation of experimental data into LES, with an view towards improved state- and parameter-estimation in real combustors. Finally, we will consider improvements to experimental signal analysis that can be achieved through incorporation of prior information obtained from LES, particularly in the context of underdetermined signal conversion problems.