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Thermodynamics
Technology-driven thermo-fluid dynamics research
n
Our research guideline is the proposition that scientific research in an engineering school should
be focused on problems with high technological relevance. A key to realizing our mission is the
close cooperation with industry in general and in particular with partners who – developing their
top-class global products at the leading edge of technology – have encountered barriers that might
be overcome by fundamental research.
Our partner industries are optimizing their technologies
towards a lower carbon footprint, integration with renew
able power sources and environmental compatibility. Their
research needs are reflected in our three research clusters:
The increase of fuel efficiency and operational flexibility
of gas turbines and large reciprocating engines at low
pollutant emissions requires fundamental research on
pollutant formation and emission, reliability, combustion
instabilities and multi-phase phenomena. Safety issues
in nuclear power plants and in the process industries are
addressed by our work on detonation and on two phase
flows. Finally, further research is devoted to the grand
challenge of providing clean water for the world.
The appreciation of our technologically oriented research
approach in the technical community is reflected by two
ASME Gas Turbine Awards for the best publication of the
year on gas turbines and numerous best paper awards
that our research group has received during the past two
decades from several organizations.
Combustion Emissions and Reliability
1. Boundary Layer Flashback in Premixed Combustion
of Highly Reactive Fuels
Furthermore, it was shown that the existence of average
boundary layer separation is not a distinct criterion for the
occurrence of confined boundary layer flashback. Instead,
flashback is triggered if local flow separation zones at the
flame bulges are large enough to locally promote flame
propagation.
2. Operational Flexibility of Gas Turbine Power Plants
Motivation and Objectives
To balance the increasing share of volatile power from
renewable power sources, highly flexible conventional
power plants are needed. Gas turbine power plants
have the potential to quickly adjust to changing power
demand but their operating range is limited by emission
Confined flame front at flashback (red) with local flow separation zones (blue)
Motivation and Objectives
If modern gas turbines are operated on highly reactive
fuels such as hydrogen, flame flashback inside the
burner’s wall boundary layer is a major issue which limits
stable and safe operation. A detailed understanding of the
underlying physical mechanism as well as tools to predict
the flashback limits are of great interest in the design of
gas turbine burners.
Approach to Solution
Boundary layer flashback is numerically investigated with
large eddy simulations. Combustion is modeled with finite
rate chemistry including detailed diffusion modelling.
This improves the insight into the mechanisms leading to
flashback.
Key Results
The numerical model can reproduce the boundary layer
flashback limits of flames confined in a duct. All relevant
physical effects are thus accounted for by the chosen
modelling approach.
OH*-chemiliminescence of the swirl stabilized jet burner with syngas injection