Response of passive scalar to momentum disturbance in a transpired channel with wall injection

Abstract

In a transpired channel, the response of turbulent field to the external concentrated momentum forcing was investigated. The flow was characterized by a strong shear layer resulting from the interaction of the main flow with the injected mass at the surface. The time scale of the shedding vortex was imposed on the external disturbance to study the subsequent evolution of the resulting flow near the surface. The imposed time characteristics were persistent in the pressure field, but the amplification of instability was not evident in the present configuration. In contrast with pressure, the effect of external disturbance was not clearly exhibited in the temperature field near the surface. This is considered to be due to the dissimilarity between the turbulent velocity and the temperature fields in the presence of wall injection. Thus, it is expected that the perturbed near-wall heat transfer characteristics should be modeled in a different way from that of the velocity field.