Christian Bak is a Senior Scientist and heading the new Poul la Cour Tunnel, that is a large aerodynamic and aeroacoustic wind tunnel dedicated wind energy. He is based at the Technical University of Denmark at the department DTU Wind Energy and has carried out research at Risø Campus since 1997. His main activity is within theoretical and experimental airfoil and rotor aerodynamics. He has been designer and co-designer of the wind turbine dedicated Risø airfoils, which are used on MW rotors. Also, different concepts of rotor design have been investigated, e.g. he is co-inventor on the use of active trailing edge flaps for wind turbines. Examples of his activities are the detailed aerodynamic full-scale measurements on a 2 MW wind turbine rotor in the so called DAN-AERO MW project, several wind tunnel measurement campaigns, principal organizer and project leader of the establishment of the artificial DTU 10 MW wind turbine and leading projects to investigate the influence of blade leading edge roughness on the aerodynamic performance. Finally, he has been the project leader of the establishment of the Poul la Cour Tunnel in Denmark.