Direct numerical simulations of transitional supersonic base flows

Abstract

Investigations of transitional supersonic base flows at M = 2.46 using Direct Numerical Simulations (DNS) are discussed. As a consequence of flow instabilities, coherent structures evolve that have a profound impact on the global flow behavior. Simulations with various circumferential domain sizes are performed to investigate the effect of coherent structures associated with different azimuthal modes on the mean flow. It is shown that the mean base pressure increases when the most dominant modes are deliberately eliminated. Results are presented for Reynolds numbers between 30,000 and 100,000. The results obtained from the DNS at ReD = 100,000 are compared to experiments at ReD = 3,300,000. ..