Direct Numerical Simulations (DNS) are carried out to investigate laminar-turbulent transition initiated by a fundamental resonance scenario for a flared cone at Mach 6. The model geometry of the flared cone experiments in the Boeing/AFOSR Mach 6 Quiet Tunnel (BAM6QT) at Purdue University is used for the simulations. Low grid-resolution simulations were first carried out in order to identify if the subharmonic or the fundamental resonance is the stronger secondary instability mechanism. The azimuthal wave number of the secondary waves that lead to the strongest secondary growth rate was found for both resonance scenarios. It was found that for the experimental conditions considered here, fundamental resonance resulted in much larger secondary instability growth rates than subharmonic resonance. Subsequently, detailed investigations were carried out using high-resolution DNS for three different azimuthal wave numbers. A case with the azimuthal wave number equal to the one that led to the strongest secondary growth rate is compared to the cases using an azimuthal wave number that is either larger or smaller compared to this wave number. For all cases the simulation results exhibit the development of stream-wise streaks of high skin friction and of high heat transfer at the cone surface. Streamwise streaks on the surface of the cone were also observed using temperature sensitive paint in the experiments carried out at Purdue University (BAM6QT facility).
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