Concurrent Experimental and Computational Study of Combustion Dynamics in a Single-Element Lean Direct Injection (LDI) Gas Turbine Combustor

摘要

A concurrent effort comprising simulation and experiment to assess the ability of high-fidelity models to predict combustion dynamics in a high pressure (1 MPa) liquid fueled lean direct inject (LDI) combustor are presented in the paper. Results from experiment and computations at an inlet air temperature of 800 K and an equivalence ratio of 0.6 are described. High frequency wall pressure and 10 kHz OH-PLIF measurements from experiment are compared with corresponding wall pressure, heat release and OH mass fraction results from hybrid RANS-LES simulations using both 2-step global and a reduced 18-reaction kinetics model. A dominant mode in the 1450-1650 Hz range- corresponding to the 4L chamber mode- is observed in the combustor, both in experiments and simulations, with a pressure fluctuation amplitude of ～10% P'/Pc. Dynamic Mode Decomposition (DMD) of the OH-PLIF data and the simulation results identify similar dominant unstable modes in the combustor.