After 2008 (Dr.-Ing. Jutta Pieringer), 2013 (Dr.-Ing. Jannis Gikadi) and 2016 (Dr.-Ing. Thomas Fiala) the Willy Messerschmidt Prize goes this year to Dr.-Ing. Vera Hoferichter for her dissertation "Boundary Layer Flashback in Premixed Combustion Systems".
Flame flashback into the premixing section is a challenge in the design of gas turbine burners since the beginning of the application of premixed combustion systems. For highly reactive fuels, especially flame flashback inside the low velocity region of the burner wall is a major issue. In the presence of combustion instabilities, boundary layer flashback can be triggered by induced velocity oscillations at the burner exit.
Vera Hoferichter experimentally investigated the effect of velocity oscillations on boundary layer flashback characteristics of turbulent hydrogen-air flames depending on oscillation amplitude and frequency. Two flashback regimes were discovered: For low oscillation amplitudes, the flashback limits in terms of minimum flow velocities in the oscillation cycle correspond to the well-established flashback limits of unconfined flames. At high oscillation amplitudes, however, the flame periodically enters the burner duct. Flashback occurs if the maximum flow velocity in the oscillation cycle falls below the flashback limit of flames confined in ducts. As the two limiting cases of confined and unconfined flames are of special interest in the design of gas turbine burners, quantitative semi-analytic prediction models were developed and validated by Vera Hoferichter based on qualitative descriptions of the flashback processes introduced in previous studies.
The prize is rewarded with 5000 EUR and goes back to Prof. Willy Messerschmitt (1898-1978), who dedicated his professional life to the development, design and application of high-performance aircraft.