Sensitivity and stability analysis of a rigid canopy flow

The present research project aims at examining the possibility of using walls covered by fexible filaments as a mean of reducing drag; we first study a rigid canopy flow model that involve several initial parameters. A sensitivity study using adjoints allows to pinpoint the parameters which influence the most both the shape of the profile and integral quantities associated to it. The intrinsic stability properties of the flow, which result from the model, are analysed with a linear local stability approach in the temporal framework. A second approach, based on adjoint stability equations, provides the sensitivity of the eigenvalues of the stability problem to changes in the flow profile, changes which can arise from a modifications of the parameters of the model.