Numerical and Experimental Analysis of a Generic Fan-in-Wing Configuration

The present investigation focuses on assessing the predictive capabilities of state-of-the-art computational fluid dynamics for a generic fan-in-wing configuration by comparison with experimental data. The objective is to reproduce a short take off and landing or a transition-flight situation without ground effect. A rotating fan is placed in the wing plane, inside of the wing's rear part and close to the root section. The obtained experimental data include force measurements, surface pressure measurements, flowfield mapping using particle image velocimetry and wool-tufts visualization. A structured mesh of the entire configuration with minimum geometrical simplifications is used to perform unsteady Reynolds-averaged Navier-Stokes computations. The area surrounding the rotor blades is set up as sliding mesh to simulate the rotation. Because of the abrupt deflection of the flow by the fan, an unsteady recirculation area is generated above the rotor blades resulting in a highly distorted inflow. The blocking of the freestream by the jet exiting the fan's nozzle creates a back pressure affecting the internal aerodynamics. The jet rolls up in a counter-rotating vortex pair with considerable impact on the wing's aerodynamic performance. Time-averaged unsteady results over one fan revolution show a good agreement with the experimental data. The major turbulence phenomena are well predicted by the simulation.