Time-resolved combustion diagnostics to study the movement of flames

In technical combustion processes, the interaction of the flame with the turbulent flow field plays a crucial role in the stability, safety and efficiency of energy conversion. Turbulent combustion is a three-dimensional multiscale phenomenon. In the operation of technical burners, transient combustion states such as spark and self-ignition, flame extinction and flashback can also occur. To investigate these phenomena, imaging laser-optical measurement methods are developed in this work and simultaneously applied to the measurement of transient flames in a turbulent environment.
The work includes fundamental further developments of imaging high-speed measurement technology with regard to quantitative imaging of scalar fields and the quasi-4D recording of the movement of flame surfaces. At the beginning, the arc is methodically stretched from simple visualizations of the unsteady flame movement to the tracking of shape features (feature tracking) to the fully quantified imaging of scalar variables, such as mixture and temperature fields. Due to the low pulse energy of the solid-state laser systems used, advanced suppression of detector noise is essential for good data quality of scalar fields. The developed WAT2d algorithm does this with outstanding performance, especially for the complex case of the spatially inhomogeneous CMOS image sensors used.
In addition to the development of diagnostics, the simultaneous application in three laser light sections for quasi-4D imaging is an innovation of this work . With this, the inherent velocity of premixed flames could be measured in a time-resolved manner for the first time in the application to a turbulent fireball. In addition to their contributions to basic research in combustion technology, the generated data sets also serve as validation data for coarse structure simulations.

Details

• Title: Time-resolved combustion diagnostics to investigate the movement of flames in turbulent flow fields
• Author: Dr. Philipp Johann Trunk
• University: Technical University of Darmstadt
• Published: 1st edition 12/31/2013
• Department: Mechanical & Process Engineering
• Product Type: Book (Hardcover)
• Product type: Dissertation
• Language: German
• Binding: Softcover (paperback)
• Dimensions: 21.0 x 14.8 cm (DIN A5)
• Scope: VI / 149 pages
• Condition: New (shrink-wrapped in foil)
• Keywords: image processing, chinematography, feature tracking, flame propagation, fluorescence, high-speed metrology, image denoising, multi-plane imaging, OH-PLIF, PIV, quantitative imaging, quasi-4D imaging, statistical analysis, tracer-LIF, transient combustion processes, Turbulence, Combustion, Wavelet Threshold

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