Volume 11, 2019Progress in Propulsion Physics – Volume 11
|425 - 446
|08 February 2019
Measuring the phase between fluctuating pressure and flame radiation intensity in a cylindrical combustion chamber
German Aerospace Center (DLR), Institute of Space Propulsion Im Langen Grund, Hardthausen 74239, Germany
2 Institute of Jet Propulsion and Turbomachinery, RWTH Aachen University 55 Templergraben, Aachen 52062, Germany
The energy transfer from the heat release of the combustion to the acoustic pressure oscillations is the driving element of combustion instabilities. This energy transfer is described by the Rayleigh criterion and depends on the phase shift between the pressure and heat release rate oscillations. A research rocket engine combustor, operated with the propellant combination hydrogen/oxygen, was equipped with dynamic pressure sensors and fibre optical probes to measure the flame radiation. This setup has been used for a phase shift analysis study which showed that unstable operation is characterized by a phase shift leading to an energy transfer from the heat release to the acoustic pressure oscillations.
© The Authors, published by EDP Sciences, 2019
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.