Modeling of the Combustion Oscillations and Soot Formation in Aerovalved Pulse Combustors

Abstract

This paper describes the modifications and evolution of a thermal pulse combustionmodel for predicting the combustion oscillations of an aerovalved 250 kW pulse combustorincorporating a soot formation-combustion model. Validation of the model is carried out from theexperimental data of an aerovalved Helmholtz type pulse combustor, where a sinusoidal air inlet massflow coupled with pressure oscillations within the combustor is needed to model the instabilities ofcombustion oscillations correctly. The model is used to investigate the influence of different boundaryconditions on combustion oscillations and soot production in the pulse combustor. The results identifythe operating conditions for which continuous oscillations, steady flames and flame extinction occur.The results also show that for ambient temperatures of inlet air (lower than 325 K) with walltemperatures lower than 1100 K soot emission from propane firing pulse combustors is negligible.