Seung-Min Jeong , Jeong-Yeol Choi
DOI Number XXX-YYY-ZZZ
Conference Number HiSST-2022-142
In our previous study, we conducted a two-dimensional delayed detached eddy simulation (DDES)
high-resolution numerical simulation on a laboratory-scale direct-connect hydrogen-fueled scramjet
combustor[1]. In this study, sampling data was accumulated up to 100 ms(millisecond) at each global
equivalence ratio case. The numerical results showed the formation/propagation/dissipation of pressure
and shock wave, so-called the “upstream-traveling shock wave”, induced by complex heat release in
the combustor. It was confirmed that this low-frequency combustion instability has order of 100 Hz,
and major instability frequency was shifted depending on changing of global equivalence ratio.
Dynamics of major instability frequency is derived identically from several experimental studies. The
previous numerical study showed underlying physics of low-frequency combustion instability on
scramjet combustor, however it has limitation, two-dimensional study. Therefore, in present study,
three-dimensional improved delayed detached eddy simulation (IDDES) with detailed laminar chemical
mechanism and partially stirred reactor (PaSR) model was performed to investigate more detailed
dynamics of low-frequency instability on scramjet combustor as preliminary staged. For high-resolution,
convective and viscous fluxes were handled by high-order accurate multi-dimensional limiting scheme.
Through comparison with supersonic co-axial jet experimental results, the constructed threedimensional LES-PaSR numerical framework has high-fidelity. The simulation was conducted under two
global equivalence ratio conditions of 0.35 and 0.45. Results showed dynamic of detailed reactive flowfield, and flame structure. A results of counter-rotating vortex pair (CRVP) shape inform that the effect
of different fuel injection pressure on fuel/air mixing process and forming of entire reactive flow-filed
of scramjet combustor. Based on present preliminary numerical study, series of comprehensive
numerical simulation will be performed with tremendous sampling time up to 30 ms.