Acoustic pulsation for heat transfer abatement in supersonic channel flow

The impact of periodic pulsation normal to the flow passage on heat and momentum transport is studied using direct numerical simulations. selected test case fully developed supersonic turbulent at Reynolds numbers Reb=ρ¯bU¯bδ/μ¯wall=3000 6000 Mach number Mcl=U¯cl/c¯cl≈1.5, bounded by isothermal walls. introduced imposing a time-periodic uniform body-force in spanwise directions, mimicking two acoustic drivers placed side-walls that are operating with 180° phase difference. Results indicate moderate forcing amplitude, velocity oscillation amplitude W̃cl≈12% bulk streamwise or W̃cl+=W̃cl/uτ≈2, can create about 8% reduction Nusselt (Nu), as well skin friction coefficient (Cf), if applied optimal period T+=Tuτ2/ν¯wall within [173, 346], where T=2π/ωf. excitation outside this band fails achieve such high levels modulations processes near Visualizing instantaneous temperature field reveals tilting near-wall structures translated into decay energy vortices an increase mean distance structures. effect reducing flux shear stress studied, resulting streaming profiles discussed.