Subsequent projects
Prof. Dr. Thomas Sattelmayer
Technische Universität München
Lehrstuhl für Thermodynamik
Prof. Vince McDonell
University of California, Irvine
Combustion Laboratory
Environmentally-Friendly Power Generation through Safe and Reliable Combustion of Hydrogen-Rich Fuels
Due to the absence of climate-damaging carbon dioxide emissions and low nitrogen oxide emissions, lean premixed combustion of hydrogen in gas turbines contributes to sustainable power generation in the future. However, this technique involves the risk of uncontrolled flame flashbacks from the combustion chamber into the premixing region. This safety-critical phenomenon has been investigated in depth during experimental studies at both the Technische Universität München (TUM) and the University of California in Irvine (UCI). Furthermore boundary layer flashback of generic burner configurations at low pressure has been investigated numerically with open source software at the TUM. On this basis boundary layer flashback of realistic burner configurations at elevated pressure will be investigated within this joint effort. In this process it will also be determined whether commercial fluid dynamics software used in the gas turbine industry is capable of modelling boundary layer flashback.
Primary project: Environmentally-Friendly Power Generation through Safe and Reliable Combustion of Hydrogen-Rich Fuels
Final Report
The capability of large eddy simulations to model unconfined boundary layer flashback was investigated during the cooperation project with the University of California in Irvine (UCI). The commercial fluid dynamics software ANSYS Fluent and the open source software OpenFOAM were used for this purpose. Validation data was obtained from previous experiments with a generic tube burner. The spatial discretization of this tube burner was similar for both solvers. The same holds for the combustion-, turbulence- and diffusion models as well as for the boundary conditions and discretization schemes. Despite the elaborate modelling approach, the experimental flashback limits could not be reproduced with ANSYS Fluent. No boundary layer flashback was observed even at significantly higher equivalence ratios than in the experiments. With OpenFOAM however, boundary layer flashback was observed exactly at the experimental flashback limit. This shows that the modelling approach is generally suited for modelling unconfined boundary layer flashback. The reason for the difference between the two solvers was however not figured out during the cooperation project. This should be investigated in the future. Due to its significantly lower resource requirements, ANSYS Fluent could then be used to simulate more complex and more realistic burner configurations at elevated pressure.