Task 2.1 Scaling laws for the effect of hydrogen content on flame dynamics and on thermoacoustic frequencies
This task will determine the scaling rules that describe how hydrogen content affects the flame transfer function and important characteristics of thermoacoustic oscillations (stability, frequency, amplitude). It will take a "divide-and-conquer" approach and dissect the web of flame-flow interactions into separate interactions (e.g. convective transport of a fuel-enriched pocket towards the flame, where it modulates the heat of reaction and the flame speed). It is expected that each interaction is driven by a different physical mechanism, so they will initially be studied separately. To this end, highly resolved combustion simulations will be performed. Guided by these simulations, physical models will be developed, and these will be validated by experiments. Once each mechanism is fully understood, the interactions will be considered in combination, and scaling rules will be established for the flame dynamics, as well as for the thermoacoustic oscillations. Individual physical models, which are a by-product of this task, will contribute to the development of fast CFD codes in task 2.2 and task 2.3. This task will build on recent work at TUM (Jaensch et al 2016).