Combustion noise comprises two components: direct combustion noise and indirect
combustion noise. The latter is the lesser studied, with entropy noise believed to be its main …

The implementation of advanced low-emission aircraft engine technologies and the
reduction of noise from airframe, fan, and jet exhaust have made noise contributions from an …

Combustion noise is becoming increasingly important as a major noise source in
aeroengines and ground based gas turbines. This is partially because advances in design …

The acoustic and entropy transfer functions of quasi-one-dimensional nozzles are studied
analytically for both subsonic and choked flows with and without shock waves. The present …

A combustion instability in a combustor terminated by a nozzle is analysed and modelled
based on a low-order Helmholtz solver. A large eddy simulation (LES) of the corresponding …

Survival of entropy waves during their advection throughout a combustor is central to the
generation of entropic sound and the subsequent effects upon thermoacoustic stability of the …

Indirect noise generated by the acceleration of synthetic compositional and entropic
perturbations through non-isentropic nozzles is measured experimentally. A physics-based …

The present paper deals with the generation of sound by the passage of acoustic or entropy
perturbations through a nozzle in the nonlinear regime and in the low-frequency limit. The …

This article revisits the problem of indirect combustion noise in nozzles of finite length. The
analytical model proposed by Moase for indirect combustion noise is rederived and applied …

The acceleration of entropy waves in the turbine stages of aero-engines and gas turbines
produces sound, which can contribute to the feedback mechanism of thermoacoustic …