Towards a Deepened Understanding of Combustion Processes Using Advanced Laser Diagnostics - TUCLA
Combustion is of utmost societal/industrial importance since it accounts for a large part of energy supply and utilization world-wide. However, combustion also significantly contributes to creation of green-house gases, such as CO2, and emissions from combustion processes constitute a major part of today's air pollutants, e.g. >90% of NOx and >50% of SOx originate from combustion devices. Detailed understanding of the complex processes in combustion, to achieve efficient fuel utilization as well as abatement of harmful environmental pollutants, poses outstanding scientific challenges. In order to address these challenges, crucial information can be obtained by non-intrusive laser-diagnostic techniques with high spatial and temporal resolution for measurements of key parameters such as species concentrations and temperatures.
The ERC-funded TUCLA project has the overall objective to develop and apply laser-diagnostic techniques for further understanding of combustion processes. The research of the project is arranged in five work packages.
Development of new diagnostic techniques.
Concepts based on structured illumination (WP1) add a new dimension to present diagnostics based on temporal, intensity and spectral properties. They allow for multi-scalar measurements and efficient suppression of background light. In WP2, ultrafast femto/picosecond lasers are employed for investigating the diagnostic applicability of filamentation, new aspects of non-linear techniques and diagnostic aspects of photodissociation phenomena. A particular highlight of the structured illumination activities has been the development of imaging of rapid sequences with unprecedented time resolution, “the world’s fastest film”. These activities have also has founded a base for an ERC starting grant awarded to Dr. Elias Kristensson.
Phenomenological combustion studies using advanced laser diagnostics.
A very important aspect of the project is to use the developed and available diagnostic techniques to assure experimental data in extremely challenging environments and together with modelling experts enhance the understanding of combustion phenomena. Research is carried out on three different topics:
- Flame structures in laminar flames at high pressure as well as turbulent flames at atmospheric/high pressure (WP3).
- Biomass gasification, where complex fuels require new techniques to measure nitrogen, alkali, chlorine and sulphur compounds, as well as for measurements inside fuel particles (WP4).
- Combustion enhancement by electric activation, which can be introduced to handle flame oscillations and instabilities (WP5).
Photo of turbulent flame (left) and laser-induced fluorescence images showing instantaneous distribution of species CH2O and OH (TUCLA WP3).
Electrical activation of combustion. A plasma, seen as a vertical blue plume, activates the chemistry of the horizontal flame (TUCLA WP5).