A novel reduced-order model method for characterization of acoustic response of laminar premixed flames

Abstract

This study presents a general, predictive and cost-efficient reduced-order modeling (ROM) technique for characterization of laminar premixed flame response under acoustic modulation. The model is built upon the kinematic flame model–G-equation to describe the flame topology and dynamics, and the novelties of the ROM lie in i) a procedure to create the compatible base flow that can reproduce the correct flame geometry and ii) the use of a physically-consistent acoustic modulation field for the characterization of flame response. This ROM addresses the significant limitations of the classical kinematic model, which is only applicable to simple flame configurations and relies on ad-hoc models for the modulation field. The ROM is validated by considering the acoustically-excited laminar premixed methane/air flames in conical and M-shape configurations, experimentally study by Durox et al. Proc. Combust. Inst., 32 (2009). To test the model availability to practical burners, a confined flame configuration Cuquel et al., Proc. Combust. Inst., 34 (2013) is also employed for model evaluation. The model accuracy is evaluated concerning flame geometrical features and flame describing function, and assessed by comparing the ROM results with both the experimental measurements and the direct-numerical-simulation results. It is found that the flame describing/transfer functions predicted by the ROM compare well with reference data, and are more accurate than those obtained from the conventional kinematic model built upon heuristically-presumed modulation fields.