Manipulating flow structures in turbulent pipe flow

Two different tools, the non-empirical resolvent analysis and the data-based dynamic mode decomposition, are employed to assess the changes induced by transpiration in the dynamics of a turbulent pipe flow. The focus is on very large-scale motions. Both analyses permit the observation of streamwise waviness in the large flow structures and how the transpiration can inhibit fluctuation in localized axial positions. We discuss under which conditions an agreement between both methodologies can be achieved.