Abstract
The inlet distortion arising on a generic fan-in-wing wind-tunnel model is investigated by means of unsteady Reynolds-averaged Navier-Stokes simulations. Flow separation occurs on the inlet lip and generates a separation bubble above the rotor blades. A distortion of the total pressure distribution at the fan inlet significantly influences the blade loading. The strong flow-velocity gradient over the inlet lip induces an increase of the axial-velocity magnitude, resulting in a reduction of incidence angle on the rotor blade. In the bubble-core region, the low axialvelocity magnitude enhances the blade incidence angle and provokes blade tip stall. Steady-state calculations, using an actuator disk approach, are also conducted to identify the key parameters affecting lip boundary-layer separation. The ratio of freestream velocity to fan jet velocity and the inlet-lip radius affect the total pressure distribution by modifying the location of the flow separation. The angle of attack on the wing has a negligible impact on the inlet distortion. An inlet lip with a large radius at its front part suppresses the lip separation and considerably reduces the total pressure distortion. Injecting a jet over the inlet lip can be a solution to actively control the lip flow.
Original language | English |
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Pages (from-to) | 16-28 |
Number of pages | 13 |
Journal | Journal of Propulsion and Power |
Volume | 27 |
Issue number | 1 |
DOIs | |
State | Published - 2011 |