LIFD Colloquium: Aimee Morgans

LEEDS INSTITUTE FOR FLUID DYNAMICS

Virtual Colloquium | 16th December 2020, 14.00 (GMT)

Professor Aimee Morgans, "Thermoacoustic instability: acoustic, flame and flow interactions"

Bio: Aimee Morgans is Professor of Thermofluids in the Department of Mechanical Engineering at Imperial College London. She studied Engineering at Cambridge, remaining at Cambridge for a PhD in aeroacoustics, completed in 2003. She then held a RAEng Research Fellowship, joining Imperial College as a Lecturer in 2007, where she has remained since. She formerly held an ERC Starting Grant, and currently holds an ERC Consolidator Grant, both on thermoacoustic instability.

Abstract: Thermoacoustic instability is caused by interactions between acoustic waves, flames and flow. It leads to damaging oscillations in the combustors of aero-engines, rocket engines, gas turbines and boilers. Carbon-free fuels like hydrogen and ammonia show increased propensity to thermoacoustic instability, and the design of futuristic aerospace engines is dependent on being able to avoid it. Because of the range of length scales involved – from the tiny flame front wrinkling to the long acoustic wavelengths - computational prediction is a real challenge.

This talk will explore the acoustic, flame and flow interactions which underpin thermoacoustic instability. We will consider the response of the flame to acoustic waves, the damping of acoustic waves at area expansions with flow separation, and the importance of “entropy noise” – the noise generated when temperature fluctuations undergo a flow acceleration. The implications for efficient computational prediction will be discussed.

Please note that this online seminar will take place via Zoom. Meeting details will be emailed to registered attendees prior to the event.