AUTOMOTIVE FAN ASSEMBLY WITH FLARED SHROUD AND FAN WITH CONFORMING BLADE TIPS
High efficiency and low noise is achieved in an automotive engine-cooling fan assembly (10) by flaring the inlet (241) to the shroud barrel (20), and shaping the tips (46) of the fan blades (4) to conform to the shape of the inlet. Separation of the flow entering the fan is reduced by extending the flare over the axial extent of the blade tips, and tip clearance losses are reduced by controlling recirculation along the entire blade tip. Blade rake is used to minimize fan deflection, thereby allowing the use of small tip clearances, which further enhance performance.