Team

For fundamental understanding of flames and the scope of model validation for numerical simulations a detailed knowledge of the velocity field ant the thermo kinetic state of generic flows is necessary. Generic flames such as stratified flames represent effects or geometries of technical combustion devices. Insights can contribute to optimize combustion processes and to improve technical applications.

Methods

Spectroscopic techniques are a very efficient, non intrusive method to provide various data about reacting and non-reacting flows. Laser spectroscopy is a sensitive state-of-the-art technique featuring the possibility of high spatial and temporal resolution measurements.

- Spontaneous Raman/Rayleigh line scattering (1D) is used to obtain all major species concentrations and the temperature at one on single shot basis. For this a high power laser pulse is focused into the probe volume. The scattered light is collected using low f number imaging optics, dispersed by a transmission spectrometer, and detected by sensitive CCD cameras.

- Laser induced fluorescence (LIF) swerves to detect resonantly minor species such as OH, CH, or CO. Combined with simultaneous Raman/Rayleigh scattering it can be extended to a quantitative technique. The presence of these radicals and intermediate species gives information about the chemical reaction state and the position of the flame front

Flames of Interest

Besides turbulent swirling methane flames especially lean premixed stratified flames with Re numbers over 10,000 and thermal powers up to 100 kW are examined. A stratified burner provides the possibility to investigate the various effects of Re number, equivalence ratio, shear, stratification, and fuel type in the context of turbulence-chemistry interaction.