Wind Tunnel Simulation of Propeller Effects in the A400M FLA-4 Model

Propeller slipstreams heavily in∞uence the aerodynamics of an airplane. These efiects are di‐cult to assess by theoretical methods alone and therefore extensive wind tunnel testing is often required. An engine system based on high-power hydraulic engines was developed and successfully used during several low-speed wind tunnel campaigns with the Airbus A400M military transport aircraft. The engine system including the hydraulic engines, the associated control system, the propeller/engine instrumentation and the balance crossing system is described in detail. Some selected results are presented, which show the importance of the efiects on the aerodynamic coe‐cients of the propeller slipstream.