We investigate the low frequency transfer functions for acoustic and entropic perturbations
through nozzles and nozzle guide vanes. Previous theories rely on the isentropic …

We propose a mathematical model from physical principles to predict the sound generated
in nozzles with dissipation. The focus is on the sound generated from the acceleration of …

Indirect noise is a significant contributor to aircraft engine noise, which needs to be
minimized in the design of aircraft engines. Indirect noise is caused by the acceleration of …

Low emission aircraft engines burn in a lean regime, which makes the combustor
susceptible to unsteady combustion. Along with improper mixing and air cooling, the …

The knowledge of the acoustic and entropic transfer functions at the boundaries of
combustors is crucial to understand the fate of flame-generated pressure perturbations and …

Combustion noise has become a major research interest within the aerospace community.
Stricter pollutant emission regulations have forced the introduction of lean premixed pre …

Pressure perturbations arise in combustors from direct noise related to the change in density
in flames, as well as the indirect (entropic) noise associated with the acceleration of non …

Pressure fluctuations associated with combustion, particularly in gas turbines, are often
linked to either the direct gas expansion due to heat release (direct noise) or the passage of …