Seminars

Abstract. The effects of introducing a two- or three-dimensional streamwise traveling wave type body forcing in a turbulent channel flow at Re=180 are investigated using direct numerical simulations (DNS). The optimal forcing shape (that is, the forcing that leads to the most amplified or highest-gain velocity response) is obtained from the resolvent analysis of McKeon & Sharma (2010) for wave-numbers and wave-speed representative of the near-wall cycle. The velocity response due to imposed forcing obtained from DNS is found to agree well with resolvent analysis predictions at small forcing amplitude. The changes in mean velocity, shear stress and kinetic energy are characterized for various amplitudes of forcing.