Two different numerical techniques for chemistry acceleration are examined with Large Eddy Simulation of a commercial swirl industrial gas turbine combustor operating at 3 bar. This work presents the results for SGT-100 Dry Low Emission (DLE) gas turbine provided by Siemens Industrial Turbomachinery Ltd. The related experimental study was performed at the German Aerospace Centre, DLR, Stuttgart, Germany.
LES with detailed chemistry calculations is an attractive tool to study turbulent premixed flames in industrial gas turbine combustors, because it can help understand turbulence-chemistry interactions, detailed flame characteristics and pollutant formation. Detailed chemistry can capture kinetically dominated processes such as ignition, extinction and pollutant formation. However, computational resources required for such calculations are often prohibitive due to the computational costs of transporting and integration of a large number of species with a wide range of chemical time-scales. Chemistry acceleration techniques can substantially reduce run-time with ideally a small loss in accuracy. Therefore, the purpose of this work is to quantify the relative increase in performance and potential loss in accuracy with two chemistry acceleration techniques namely Clustering, Dynamic Mechanism Reduction (DMR) and their combination.
The results show that the different chemistry acceleration techniques do not compromise the time averaged flow statistics. However, there are some differences in NO and CO emissions. Chemistry acceleration techniques yield up to ∼3 times speed-up of the simulation.