Combustion Noise Dependency on Thermal Load and Global Equivalence Ratio in a Swirl-Stabilized Combustor

Abstract

A laboratory scale, swirl stabilized burner is investigated in view of the impact of global equivalence ratio and thermal power variation on broadband combustion noise emission. The PRECCINSTA burner (Prediction and Control of Combustion Instabilities in Industrial Gas Turbines) is operated at atmospheric conditions. The presented combustion noise studies are based on a perfectly premixed configuration, where methane is burnt with air. From experiments, newly measured sound pressure spectra in the combustion system with well-defined acoustic boundary conditions are presented for several thermal loads and global equivalent ratios. For the combustion noise simulations, the hybrid CFD/CCA approach 3D FRPM-CN (Fast Random Particle Method for Combustion Noise Prediction) is used. Numerical simulation results of CFD and combustion acoustics are compared with experimental data in terms of flow field and combustion. 3D FRPM-CN is then assessed for its prediction capability of effects of combustion parameter variation on broadband noise emission. Numerical results are interpreted with a method for spectral mode decomposition. High frequency acoustic modes in the combustion chamber are identified and characterized. Sound pressure spectra from numerical simulations are evaluated with experimental data in view of reproduction of absolute direct combustion noise levels and shape of spectra. With the study presented in this work, not only a combustion noise prediction tools is further validated, but also a large experimental data base for combustion noise and thermo-acoustics validation in swirl-stabilized, confined configurations is introduced.

A comprehensive investigation of acoustic power level in a moderate or intense low oxygen dilution in a jet-in-hot-coflow under various working conditions

“…Pillai and Kurose [41] analyzed the characteristics of noise radiation in a turbulent spray flame. Grimm et al [42] investigated the impact of global equivalence ratio and thermal power variation on broadband combustion noise emission in a swirl-stabilized burner experimentally and numerically.…”

Modal decomposition of the unsteady non-reactive flow field in a swirl-stabilized combustor operated by a Lean Premixed injection system

“…In this way, the POD technique applied to numerical studies has characterised the Vortex Breakdown Bubble and the transition to helical breakdown modes in non-reacting conditions [38,39], the combustion dynamics and flame interactions in reactive conditions [40][41][42][43], and the impact of variations of thermal load and global equivalence ratio on combustion acoustics noise levels [44].…”

Computational study on the non-reacting flow in Lean Direct Injection gas turbine combustors through Eulerian-Lagrangian Large-Eddy Simulations

“…Nevertheless, as a consequence of experimental diagnosis shortcomings (e.g., the sampling frequency of the Stereo PIV system can be sometimes much smaller than the PVC frequency [157]), temporal and spatial-detailed CFD simulations have emerged as a potential tool to successfully characterise the coherent structures within the combustor through pressure, vorticity and species signals decomposition rather than dealing just with velocity. In this way, the POD technique applied to numerical studies has characterised the VBB and the transition to helical breakdown modes in non-reacting conditions [80,167,168], the combustion dynamics and flame interactions in reacting conditions [115,[169][170][171][172] and the impact of variations of thermal load and global equivalence ratio on combustion acoustics noise levels [173,174].…”