Computational Assessment of Wind Tunnel Flow in Closed and Open Section Model Rotor Tests

A qualitative analysis of the flow inside the closed and open test sections of the Politecnico di Milano large wind tunnel in the presence of rotor effects has been carried out with the ROSITA (ROtorcraft Software ITAly) Reynolds-averaged Navier-Stokes solver. The rotor is represented as an actuator disk. The simulations in the closed section help determine the flow breakdown boundaries in terms of tunnel-operating parameters. In the open section, no flow breakdown may be identified, but the operating conditions in which the rotor wake is escaping from the tunnel circuit can be defined. Recommendations are provided for experimental measurements to enable online detection of the flow breakdown in the closed section and the wake deflection in the open section