Computational Studies of Thermo-Acoustics Instabilities of Turbulent Premixed Combustion in Backward-Facing Step Using LES

Backward-facing step is commonly used in applications where highly turbulent flow separation and turbulent mixing are sought and thus, turbulent combustion is one of the applications where the backward-facing step is commonly used. The interaction between combustion and acoustic instabilities is still not fully understood and thus, further studies are required. Hence, the current research concerns the impact of the Reynolds number on the turbulence enhancement and acoustic noise in a backward-facing step turbulent flow. The computational studies are carried out using the large-eddy simulation (LES) approach. The main objective of the present research is to provide a comprehensive insight into the physical phenomena associated with the acoustic instabilities, and noise, of turbulent flows past backward facing step. The present research reveals that the expansion ratio enhances the turbulence intensity and acoustics noise.