Session: 05-04: Combustion Measurements 1

Submission Number: 178414

Spectral Proper Orthogonal Decomposition Applied to High-Speed Heterodyne Background Oriented Schlieren for the Detection of Heat Release Induced Modes 

The High-Speed Heterodyne Background-Oriented Schlieren (HBOS) technique is employed in the context of an aero-derivative burner to investigate the underlying flow dynamics and heat-release mechanisms characteristic of such combustion systems. The primary objective of integrating a high-speed imaging approach is to enable time-resolved visualization and quantitative analysis of the thermo-fluidic processes governing the burner operation. HBOS, an advanced optical diagnostic method, facilitates the concurrent measurement of density gradients and heat release, thereby providing a comprehensive perspective on the coupled aerodynamic and thermochemical phenomena.

In this study, image sequences obtained via a high-speed camera are processed to reconstruct refractive index gradients and extract pertinent flow features. In order to further interpret the complex spatio-temporal data, Principal Component Analysis (PCA) is employed to identify dominant line-of-sight (LOS) aerothermal modes. This enables the decomposition of coherent structures and their relative contributions to the overall dynamics.

The present study investigates the influence of boundary conditions on the modal behavior and coupling between flow and heat-release fluctuations in both open and confined flame configurations. A comparison of the resulting modal characteristics and reconstructed fields with previously reported experimental and numerical findings demonstrates consistency with established literature. This comparison also highlights the potential of HBOS combined with data-driven modeling for advanced combustion diagnostics.

Presenting Author: Sami Tasmany Institute of Thermal Turbomachinery and Machine Dynamics

Presenting Author Biography: Graduated at Politecnico di Milano, Milano, Lombardia, Italia.
Currently PhD candidate at the Institute of Thermal Turbomachinery and Machine Dynamics, Graz University of technology, Graz, Steiermark, Österreich.

Authors:

Sami Tasmany Institute of Thermal Turbomachinery and Machine Dynamics
Nina Paulitsch Institute of Thermal Turbomachinery and Machine Dynamics
Giorgia Bozzo Institute of Thermal Turbomachinery and Machine Dynamics
Jakob Woisetschläger Institute of Thermal Turbomachinery and Machine Dynamics
Patrick René Jagerhofer Graz University of Technology - Institute for Thermal Turbomachinery and Machine Dynamics
Johannes Gürtler Laboratory for Measurement and Sensor System Technique
Robert Kuschmierz Laboratory for Measurement and Sensor System Technique
Jürgen Czarske Laboratory for Measurement and Sensor System Technique