CFD simulation of combustion characteristics and re-ignition sources in a valveless pulse combustor

Abstract EN

Due to the complex mechanism of the combustion process in the pulse combustor, it is challenging to conduct experimental applications to investigate the sources of re-ignition.

the paper presents a 3D numerical simulation study of the re-ignition mechanism in a Helmholtz-type valveless pulse combustor.

the numerical simulation is conducted by involving the fundamental equations of Reynolds averaged Navier-stokes.

the turbulence-chemistry interaction scheme is implemented using the eddy dissipation model and a propane-air mixture utilizing a two-step process.

the CFD combustion model was used to predict the limit cycle of thermoacoustic instability in a laboratory-scale pulse combustor and was examined with experimental results to assess its validity.

our simulation study revealed there was a weak re-ignition source at the beginning of the combustion chamber, but it was extinct due to insufficient thermal energy.

the main re-ignition source occurs when the high-temperature gas in the hot zone recirculates in counter-rotating and pulls the flame to extend around the bluff body.

the combustible air-fuel mixture instantly interacts with the bluff body's extended flame, causing self-ignite to the downstream mixture flow.

the results confirm that the model CFD simulations are capable of accurately capturing the periodic re-ignition sources and scientifically proving the Rayleigh criteria.