Thermoacoustic Response & NOx Emissions of H₂ Micromix Flames
Why hydrogen micromix?
Hydrogen combustion promises carbon-free gas-turbine power, but its high flame speed and reactivity make it prone to thermoacoustic instability and localised NOx formation.
The micromix concept splits combustion into many small, rapidly-mixed flames to suppress both — yet the unsteady physics remain poorly resolved.
High-fidelity LES with acoustic forcing
A compressible Large-Eddy Simulation framework in STAR-CCM+ with finite-rate chemistry captures the resolved turbulence–chemistry interaction across the full injector array.
The combustor is acoustically forced across a frequency sweep. Dynamic Mode Decomposition extracts the dominant thermoacoustic modes from the coupled pressure and heat-release fields.
Coupling, mode shapes & emissions
The LES resolves a dominant thermoacoustic mode and its phase relationship with the flame surface. The work maps how injector geometry shifts the flame transfer function and the resulting trade-off between instability margin and NOx output.
In detail
What this work delivers
Resolved coupling
LES captures the two-way coupling between acoustics and the flame array that low-order models miss.
Design sensitivity
Injector geometry measurably shifts the flame transfer function and instability margin.
Emissions map
A quantified path between thermoacoustic stability and NOx output.
H. H.-W. Funke et al., "Numerical and experimental evaluation of a hydrogen micromix combustor," 2019.
T. Poinsot & D. Veynante, Theoretical and Numerical Combustion.
OpenFOAM v2312 User Guide, OpenCFD Ltd.