Uncertainty quantification in large eddy simulations of a rich-dome aviation gas turbine

Abstract

In this work, a rich-dome aviation combustor operating over a range of high-power conditions is investigated using multiple Large Eddy Simulations (LES). The LES flow solutions are obtained with CharLES, a massively-parallel framework for compressible, reacting flows in complex geometries. The CharLES solver constructs a body-conforming mesh from the 3D Voronoi diagram of a set of regularly distributed seed points within the computational domain. The computational domain spans from the compressor exit plane to the combustor exit plane and includes the passages around the combustor liners. A baseline solution is first obtained at nominal conditions using a reference grid and validated using non-dimensional exit profile. Non-intrusive Uncertainty Quantification (UQ) is then employed to characterize the uncertainties on a few key combustor metrics. It is found that the overall variability at the exit plane is actually larger than the input uncertainty. This highlights the non-linear coupling between the flow and the reacting processes inside the combustor. Areas of high temperature variability are highlighted, especially downstream of the dilution holes. Finally, it is found that uncertainty in fuel flowrate has a greater impact on outlet quantities whereas uncertainty in air inlet temperature has a greater impact on liner quantities.