Session: 04-21: Combustion Dynamics - Flame Transfer Functions

Paper Number: 84357

84357 - "From Pressure Time Series Data to Flame Transfer Functions: A Framework for Perfectly-Premixed Swirling Flames " 

Combustion instabilities (CIs) remain a major technological challenge towards low-emission energy generation. A key element for the analysis of CIs is the Flame Transfer Function (FTF), which is a crucial quantity to determine the stability of the combustion chamber. However, the FTF is not known a priori. Typically, it is determined experimentally and/or numerically and, hence, requires significant effort in measurement diagnostics and/or computational resources, respectively. We present a novel methodology that combines (i) a physically-based analytical model of the FTF for swirling flows, together with (ii) recent theoretical developments on the propagation speed of inertial waves and (iii) data-driven FTF modeling strategies using pressure times series. We validate the method by using experimentally recorded pressure time series and FTF measurements of a turbulent, lean-premixed, swirling flame. The position of the swirler is varied for three power ratings (30kW, 50kW and 70kW), which result in 6 different operating conditions for which the FTFs were measured. We demonstrate the accurate FTF estimation of all cases. Note that this method does not require heavy computational requirements: the estimation procedure is implemented in Matlab and takes in average less than 30mins per computation on a standard work station, which renders this method suitable for industrial purposes.

Presenting Author: Abdulla Ghani TU Berlin

Presenting Author Biography: Junior Professor TU Berlin

Authors:

Abdulla Ghani TU Berlin
Alp Albayrak TU Berlin