Publications

Second mode growth in a high-velocity boundary layer using stability theory and DNS

Harris, Shaun R.; Wagnild, Ross M.

Direct numerical simulations (DNS) were conducted of a high-velocity flat plate boundary layer with time-periodic fluctuating inflow. The DNS fluctuation growth and evolution over the plate is then compared to the solution as computed using classical linear stability theory (LST) and the parabolized stability equations (PSE) of a second mode eigenfunction. The agreement observed between the eigenfunction from LST and the fundamental harmonic of the temporal Fourier transform (FT) of the DNS simulation demonstrates the ability of the solver to capture the initiation and linear growth of a hypersonic boundary layer instability. The work enables the study of the perturbation’s evolution in the boundary layer as well as provides confidence in the numerical solver to study further development towards non-linear growth and eventual transition to turbulence.