Self-sustained combustion instabilities are one of the most plaguing challenges and
problems in lean-conditioned propulsion and land-based engine systems, such as rocket …

Chemical mechanical planarization (CMP) has been widely used in the semiconductor
industry to create planar surfaces with a combination of chemical and mechanical forces. A …

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

Entropy waves play an important role in the production of indirect combustion noise and
thermoacoustic instability. The characteristics of entropy waves from swirling flames have …

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 …

Low-order thermoacoustic models are qualitatively correct, but typically, they are
quantitatively inaccurate. We propose a time-domain bias-aware method to make …

Broadband combustion noise is a major part of the total noise radiated by modern jet
engines. It comprises two components: direct noise originating from the unsteady heat …

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

Flow disturbances are generated inside a duct via pulsed injection of helium into a flow of
air. This leads to the generation of an acoustic pulse (direct noise), as well as the production …

In this work, we investigate both numerically and theoretically the sound generated by
entropy waves passing through sudden area expansions. This is a canonical configuration …