Category: Fluid Dynamics

Jet aero-acoustics

  The development of aircraft transportation has brought an increase of air traffic volume and issues related to environmental aspects such as carbon and NOx emissions and noise pollution. The jet exhausting from aircraft engine is the responsible for pollutant discharge and one of the main sources of community and interior noise. Jet noise is a challenging topic for the scientific community. Despite of many years of research, the mechanism by which turbulent structures generate noise is still unknown. The...

Gas Turbine Combustion Instabilities Diagnosis

Combustion of lean and preformed mixtures (Lean Premixed Combustion, LPM) is the current state of the art among the combustion technologies for stationary gas turbine plants, fuelled by natural gas. This in terms both of energy conversion efficiency both of harmful emission reduction. However, just the ultra-lean premixed flames are those most prone to thermo-acoustic instabilities, that is to the onset of large amplitude pressure fluctuations, dues to the coupling between the unsteady expansion effects of heat release fluctuations and...